From 400b7f6d1465815cc3992c009caa760a668928e5 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Wed, 8 Sep 2021 16:43:57 +0100 Subject: [PATCH 01/10] linux-user: Fix coding style nits in qemu.h MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We're about to move a lot of the code in qemu.h out into different header files; fix the coding style nits first so that checkpatch is happy with the pure code-movement patches. This is mostly block-comment style but also a few whitespace issues. Signed-off-by: Peter Maydell Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Richard Henderson Message-Id: <20210908154405.15417-2-peter.maydell@linaro.org> Signed-off-by: Laurent Vivier --- linux-user/qemu.h | 47 ++++++++++++++++++++++++++++++----------------- 1 file changed, 30 insertions(+), 17 deletions(-) diff --git a/linux-user/qemu.h b/linux-user/qemu.h index 3b0b6b75fe..34b975ba50 100644 --- a/linux-user/qemu.h +++ b/linux-user/qemu.h @@ -15,12 +15,14 @@ #include "target_syscall.h" #include "exec/gdbstub.h" -/* This is the size of the host kernel's sigset_t, needed where we make +/* + * This is the size of the host kernel's sigset_t, needed where we make * direct system calls that take a sigset_t pointer and a size. */ #define SIGSET_T_SIZE (_NSIG / 8) -/* This struct is used to hold certain information about the image. +/* + * This struct is used to hold certain information about the image. * Basically, it replicates in user space what would be certain * task_struct fields in the kernel */ @@ -48,13 +50,13 @@ struct image_info { abi_ulong env_strings; abi_ulong file_string; uint32_t elf_flags; - int personality; + int personality; abi_ulong alignment; /* The fields below are used in FDPIC mode. */ abi_ulong loadmap_addr; uint16_t nsegs; - void *loadsegs; + void *loadsegs; abi_ulong pt_dynamic_addr; abi_ulong interpreter_loadmap_addr; abi_ulong interpreter_pt_dynamic_addr; @@ -98,8 +100,10 @@ struct emulated_sigtable { target_siginfo_t info; }; -/* NOTE: we force a big alignment so that the stack stored after is - aligned too */ +/* + * NOTE: we force a big alignment so that the stack stored after is + * aligned too + */ typedef struct TaskState { pid_t ts_tid; /* tid (or pid) of this task */ #ifdef TARGET_ARM @@ -134,20 +138,23 @@ typedef struct TaskState { struct emulated_sigtable sync_signal; struct emulated_sigtable sigtab[TARGET_NSIG]; - /* This thread's signal mask, as requested by the guest program. + /* + * This thread's signal mask, as requested by the guest program. * The actual signal mask of this thread may differ: * + we don't let SIGSEGV and SIGBUS be blocked while running guest code * + sometimes we block all signals to avoid races */ sigset_t signal_mask; - /* The signal mask imposed by a guest sigsuspend syscall, if we are + /* + * The signal mask imposed by a guest sigsuspend syscall, if we are * currently in the middle of such a syscall */ sigset_t sigsuspend_mask; /* Nonzero if we're leaving a sigsuspend and sigsuspend_mask is valid. */ int in_sigsuspend; - /* Nonzero if process_pending_signals() needs to do something (either + /* + * Nonzero if process_pending_signals() needs to do something (either * handle a pending signal or unblock signals). * This flag is written from a signal handler so should be accessed via * the qatomic_read() and qatomic_set() functions. (It is not accessed @@ -168,8 +175,10 @@ extern unsigned long mmap_min_addr; /* ??? See if we can avoid exposing so much of the loader internals. */ -/* Read a good amount of data initially, to hopefully get all the - program headers loaded. */ +/* + * Read a good amount of data initially, to hopefully get all the + * program headers loaded. + */ #define BPRM_BUF_SIZE 1024 /* @@ -184,7 +193,7 @@ struct linux_binprm { int argc, envc; char **argv; char **envp; - char * filename; /* Name of binary */ + char *filename; /* Name of binary */ int (*core_dump)(int, const CPUArchState *); /* coredump routine */ }; @@ -212,10 +221,11 @@ void do_init_thread(struct target_pt_regs *regs, struct image_info *infop); abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp, abi_ulong stringp, int push_ptr); int loader_exec(int fdexec, const char *filename, char **argv, char **envp, - struct target_pt_regs * regs, struct image_info *infop, + struct target_pt_regs *regs, struct image_info *infop, struct linux_binprm *); -/* Returns true if the image uses the FDPIC ABI. If this is the case, +/* + * Returns true if the image uses the FDPIC ABI. If this is the case, * we have to provide some information (loadmap, pt_dynamic_info) such * that the program can be relocated adequately. This is also useful * when handling signals. @@ -283,7 +293,8 @@ void probe_guest_base(const char *image_name, * with any of the host errno values.) */ -/* A guide to using safe_syscall() to handle interactions between guest +/* + * A guide to using safe_syscall() to handle interactions between guest * syscalls and guest signals: * * Guest syscalls come in two flavours: @@ -392,7 +403,8 @@ extern long safe_syscall_base(int *pending, long number, ...); #else -/* Fallback for architectures which don't yet provide a safe-syscall assembly +/* + * Fallback for architectures which don't yet provide a safe-syscall assembly * fragment; note that this is racy! * This should go away when all host architectures have been updated. */ @@ -736,7 +748,8 @@ static inline int regpairs_aligned(void *cpu_env, int num) { return 0; } */ void preexit_cleanup(CPUArchState *env, int code); -/* Include target-specific struct and function definitions; +/* + * Include target-specific struct and function definitions; * they may need access to the target-independent structures * above, so include them last. */ From a44d57a3b9aef9691402560de5da3c03cadd16e5 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Wed, 8 Sep 2021 16:43:58 +0100 Subject: [PATCH 02/10] linux-user: Split strace prototypes into strace.h MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The functions implemented in strace.c are only used in a few files in linux-user; split them out of qemu.h and into a new strace.h header which we include in the places that need it. Signed-off-by: Peter Maydell Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Richard Henderson Message-Id: <20210908154405.15417-3-peter.maydell@linaro.org> Signed-off-by: Laurent Vivier --- linux-user/qemu.h | 18 ------------------ linux-user/signal.c | 1 + linux-user/strace.c | 2 ++ linux-user/strace.h | 38 ++++++++++++++++++++++++++++++++++++++ linux-user/syscall.c | 1 + 5 files changed, 42 insertions(+), 18 deletions(-) create mode 100644 linux-user/strace.h diff --git a/linux-user/qemu.h b/linux-user/qemu.h index 34b975ba50..ad2d49fed9 100644 --- a/linux-user/qemu.h +++ b/linux-user/qemu.h @@ -415,24 +415,6 @@ extern long safe_syscall_base(int *pending, long number, ...); /* syscall.c */ int host_to_target_waitstatus(int status); -/* strace.c */ -void print_syscall(void *cpu_env, int num, - abi_long arg1, abi_long arg2, abi_long arg3, - abi_long arg4, abi_long arg5, abi_long arg6); -void print_syscall_ret(void *cpu_env, int num, abi_long ret, - abi_long arg1, abi_long arg2, abi_long arg3, - abi_long arg4, abi_long arg5, abi_long arg6); -/** - * print_taken_signal: - * @target_signum: target signal being taken - * @tinfo: target_siginfo_t which will be passed to the guest for the signal - * - * Print strace output indicating that this signal is being taken by the guest, - * in a format similar to: - * --- SIGSEGV {si_signo=SIGSEGV, si_code=SI_KERNEL, si_addr=0} --- - */ -void print_taken_signal(int target_signum, const target_siginfo_t *tinfo); - /* signal.c */ void process_pending_signals(CPUArchState *cpu_env); void signal_init(void); diff --git a/linux-user/signal.c b/linux-user/signal.c index a8faea6f09..ee1934947a 100644 --- a/linux-user/signal.c +++ b/linux-user/signal.c @@ -22,6 +22,7 @@ #include #include "qemu.h" +#include "strace.h" #include "trace.h" #include "signal-common.h" diff --git a/linux-user/strace.c b/linux-user/strace.c index cce0a5d1e3..ee3429fae8 100644 --- a/linux-user/strace.c +++ b/linux-user/strace.c @@ -1,4 +1,5 @@ #include "qemu/osdep.h" + #include #include #include @@ -14,6 +15,7 @@ #include #include #include "qemu.h" +#include "strace.h" struct syscallname { int nr; diff --git a/linux-user/strace.h b/linux-user/strace.h new file mode 100644 index 0000000000..1e232d07fc --- /dev/null +++ b/linux-user/strace.h @@ -0,0 +1,38 @@ +/* + * strace.h: prototypes for linux-user builtin strace handling + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see . + */ + +#ifndef LINUX_USER_STRACE_H +#define LINUX_USER_STRACE_H + +void print_syscall(void *cpu_env, int num, + abi_long arg1, abi_long arg2, abi_long arg3, + abi_long arg4, abi_long arg5, abi_long arg6); +void print_syscall_ret(void *cpu_env, int num, abi_long ret, + abi_long arg1, abi_long arg2, abi_long arg3, + abi_long arg4, abi_long arg5, abi_long arg6); +/** + * print_taken_signal: + * @target_signum: target signal being taken + * @tinfo: target_siginfo_t which will be passed to the guest for the signal + * + * Print strace output indicating that this signal is being taken by the guest, + * in a format similar to: + * --- SIGSEGV {si_signo=SIGSEGV, si_code=SI_KERNEL, si_addr=0} --- + */ +void print_taken_signal(int target_signum, const target_siginfo_t *tinfo); + +#endif /* LINUX_USER_STRACE_H */ diff --git a/linux-user/syscall.c b/linux-user/syscall.c index ccd3892b2d..4ac2801e49 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -127,6 +127,7 @@ #include "uname.h" #include "qemu.h" +#include "strace.h" #include "qemu/guest-random.h" #include "qemu/selfmap.h" #include "user/syscall-trace.h" From 2113aed687cb0b84ad512c440c1edf6eea8fcde2 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Wed, 8 Sep 2021 16:43:59 +0100 Subject: [PATCH 03/10] linux-user: Split signal-related prototypes into signal-common.h MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Split the signal related prototypes into the existing header file signal-common.h, and include it in those places that now require it. Signed-off-by: Peter Maydell Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Richard Henderson Message-Id: <20210908154405.15417-4-peter.maydell@linaro.org> Signed-off-by: Laurent Vivier --- linux-user/aarch64/cpu_loop.c | 1 + linux-user/alpha/cpu_loop.c | 1 + linux-user/arm/cpu_loop.c | 1 + linux-user/cris/cpu_loop.c | 1 + linux-user/fd-trans.c | 1 + linux-user/hexagon/cpu_loop.c | 1 + linux-user/hppa/cpu_loop.c | 1 + linux-user/i386/cpu_loop.c | 1 + linux-user/m68k/cpu_loop.c | 1 + linux-user/main.c | 1 + linux-user/microblaze/cpu_loop.c | 1 + linux-user/mips/cpu_loop.c | 1 + linux-user/nios2/cpu_loop.c | 1 + linux-user/openrisc/cpu_loop.c | 1 + linux-user/ppc/cpu_loop.c | 1 + linux-user/qemu.h | 36 -------------------------------- linux-user/riscv/cpu_loop.c | 1 + linux-user/s390x/cpu_loop.c | 1 + linux-user/sh4/cpu_loop.c | 1 + linux-user/signal-common.h | 36 ++++++++++++++++++++++++++++++++ linux-user/sparc/cpu_loop.c | 1 + linux-user/syscall.c | 1 + linux-user/xtensa/cpu_loop.c | 1 + 23 files changed, 57 insertions(+), 36 deletions(-) diff --git a/linux-user/aarch64/cpu_loop.c b/linux-user/aarch64/cpu_loop.c index ee72a1c20f..5cac76f67b 100644 --- a/linux-user/aarch64/cpu_loop.c +++ b/linux-user/aarch64/cpu_loop.c @@ -21,6 +21,7 @@ #include "qemu-common.h" #include "qemu.h" #include "cpu_loop-common.h" +#include "signal-common.h" #include "qemu/guest-random.h" #include "semihosting/common-semi.h" #include "target/arm/syndrome.h" diff --git a/linux-user/alpha/cpu_loop.c b/linux-user/alpha/cpu_loop.c index 7ce2461a02..8464047368 100644 --- a/linux-user/alpha/cpu_loop.c +++ b/linux-user/alpha/cpu_loop.c @@ -21,6 +21,7 @@ #include "qemu-common.h" #include "qemu.h" #include "cpu_loop-common.h" +#include "signal-common.h" void cpu_loop(CPUAlphaState *env) { diff --git a/linux-user/arm/cpu_loop.c b/linux-user/arm/cpu_loop.c index 69632d15be..5556d38146 100644 --- a/linux-user/arm/cpu_loop.c +++ b/linux-user/arm/cpu_loop.c @@ -22,6 +22,7 @@ #include "qemu.h" #include "elf.h" #include "cpu_loop-common.h" +#include "signal-common.h" #include "semihosting/common-semi.h" #define get_user_code_u32(x, gaddr, env) \ diff --git a/linux-user/cris/cpu_loop.c b/linux-user/cris/cpu_loop.c index 334edddd1e..8c9fc3127e 100644 --- a/linux-user/cris/cpu_loop.c +++ b/linux-user/cris/cpu_loop.c @@ -21,6 +21,7 @@ #include "qemu-common.h" #include "qemu.h" #include "cpu_loop-common.h" +#include "signal-common.h" void cpu_loop(CPUCRISState *env) { diff --git a/linux-user/fd-trans.c b/linux-user/fd-trans.c index 86b6f484d3..48203c1af9 100644 --- a/linux-user/fd-trans.c +++ b/linux-user/fd-trans.c @@ -28,6 +28,7 @@ #endif #include "qemu.h" #include "fd-trans.h" +#include "signal-common.h" enum { QEMU_IFLA_BR_UNSPEC, diff --git a/linux-user/hexagon/cpu_loop.c b/linux-user/hexagon/cpu_loop.c index bc34f5d7c3..348d2dc341 100644 --- a/linux-user/hexagon/cpu_loop.c +++ b/linux-user/hexagon/cpu_loop.c @@ -21,6 +21,7 @@ #include "qemu/osdep.h" #include "qemu.h" #include "cpu_loop-common.h" +#include "signal-common.h" #include "internal.h" void cpu_loop(CPUHexagonState *env) diff --git a/linux-user/hppa/cpu_loop.c b/linux-user/hppa/cpu_loop.c index 82d8183821..c3661994a5 100644 --- a/linux-user/hppa/cpu_loop.c +++ b/linux-user/hppa/cpu_loop.c @@ -20,6 +20,7 @@ #include "qemu/osdep.h" #include "qemu.h" #include "cpu_loop-common.h" +#include "signal-common.h" static abi_ulong hppa_lws(CPUHPPAState *env) { diff --git a/linux-user/i386/cpu_loop.c b/linux-user/i386/cpu_loop.c index f813e87294..ee2e139a06 100644 --- a/linux-user/i386/cpu_loop.c +++ b/linux-user/i386/cpu_loop.c @@ -21,6 +21,7 @@ #include "qemu-common.h" #include "qemu.h" #include "cpu_loop-common.h" +#include "signal-common.h" /***********************************************************/ /* CPUX86 core interface */ diff --git a/linux-user/m68k/cpu_loop.c b/linux-user/m68k/cpu_loop.c index c7a500b58c..3a330401bf 100644 --- a/linux-user/m68k/cpu_loop.c +++ b/linux-user/m68k/cpu_loop.c @@ -21,6 +21,7 @@ #include "qemu-common.h" #include "qemu.h" #include "cpu_loop-common.h" +#include "signal-common.h" void cpu_loop(CPUM68KState *env) { diff --git a/linux-user/main.c b/linux-user/main.c index a6094563b6..4f51670735 100644 --- a/linux-user/main.c +++ b/linux-user/main.c @@ -49,6 +49,7 @@ #include "cpu_loop-common.h" #include "crypto/init.h" #include "fd-trans.h" +#include "signal-common.h" #ifndef AT_FLAGS_PRESERVE_ARGV0 #define AT_FLAGS_PRESERVE_ARGV0_BIT 0 diff --git a/linux-user/microblaze/cpu_loop.c b/linux-user/microblaze/cpu_loop.c index c3396a6e09..0d2c8f8dea 100644 --- a/linux-user/microblaze/cpu_loop.c +++ b/linux-user/microblaze/cpu_loop.c @@ -21,6 +21,7 @@ #include "qemu-common.h" #include "qemu.h" #include "cpu_loop-common.h" +#include "signal-common.h" void cpu_loop(CPUMBState *env) { diff --git a/linux-user/mips/cpu_loop.c b/linux-user/mips/cpu_loop.c index 9d813ece4e..7dfaa0cb1e 100644 --- a/linux-user/mips/cpu_loop.c +++ b/linux-user/mips/cpu_loop.c @@ -21,6 +21,7 @@ #include "qemu-common.h" #include "qemu.h" #include "cpu_loop-common.h" +#include "signal-common.h" #include "elf.h" #include "internal.h" #include "fpu_helper.h" diff --git a/linux-user/nios2/cpu_loop.c b/linux-user/nios2/cpu_loop.c index 9869083fa1..68f95d7ad7 100644 --- a/linux-user/nios2/cpu_loop.c +++ b/linux-user/nios2/cpu_loop.c @@ -20,6 +20,7 @@ #include "qemu/osdep.h" #include "qemu.h" #include "cpu_loop-common.h" +#include "signal-common.h" void cpu_loop(CPUNios2State *env) { diff --git a/linux-user/openrisc/cpu_loop.c b/linux-user/openrisc/cpu_loop.c index b33fa77718..f6c6785988 100644 --- a/linux-user/openrisc/cpu_loop.c +++ b/linux-user/openrisc/cpu_loop.c @@ -21,6 +21,7 @@ #include "qemu-common.h" #include "qemu.h" #include "cpu_loop-common.h" +#include "signal-common.h" void cpu_loop(CPUOpenRISCState *env) { diff --git a/linux-user/ppc/cpu_loop.c b/linux-user/ppc/cpu_loop.c index fa91ea0eed..ace431238c 100644 --- a/linux-user/ppc/cpu_loop.c +++ b/linux-user/ppc/cpu_loop.c @@ -21,6 +21,7 @@ #include "qemu-common.h" #include "qemu.h" #include "cpu_loop-common.h" +#include "signal-common.h" static inline uint64_t cpu_ppc_get_tb(CPUPPCState *env) { diff --git a/linux-user/qemu.h b/linux-user/qemu.h index ad2d49fed9..76d3f5e7eb 100644 --- a/linux-user/qemu.h +++ b/linux-user/qemu.h @@ -415,42 +415,6 @@ extern long safe_syscall_base(int *pending, long number, ...); /* syscall.c */ int host_to_target_waitstatus(int status); -/* signal.c */ -void process_pending_signals(CPUArchState *cpu_env); -void signal_init(void); -int queue_signal(CPUArchState *env, int sig, int si_type, - target_siginfo_t *info); -void host_to_target_siginfo(target_siginfo_t *tinfo, const siginfo_t *info); -void target_to_host_siginfo(siginfo_t *info, const target_siginfo_t *tinfo); -int target_to_host_signal(int sig); -int host_to_target_signal(int sig); -long do_sigreturn(CPUArchState *env); -long do_rt_sigreturn(CPUArchState *env); -abi_long do_sigaltstack(abi_ulong uss_addr, abi_ulong uoss_addr, - CPUArchState *env); -int do_sigprocmask(int how, const sigset_t *set, sigset_t *oldset); -abi_long do_swapcontext(CPUArchState *env, abi_ulong uold_ctx, - abi_ulong unew_ctx, abi_long ctx_size); -/** - * block_signals: block all signals while handling this guest syscall - * - * Block all signals, and arrange that the signal mask is returned to - * its correct value for the guest before we resume execution of guest code. - * If this function returns non-zero, then the caller should immediately - * return -TARGET_ERESTARTSYS to the main loop, which will take the pending - * signal and restart execution of the syscall. - * If block_signals() returns zero, then the caller can continue with - * emulation of the system call knowing that no signals can be taken - * (and therefore that no race conditions will result). - * This should only be called once, because if it is called a second time - * it will always return non-zero. (Think of it like a mutex that can't - * be recursively locked.) - * Signals will be unblocked again by process_pending_signals(). - * - * Return value: non-zero if there was a pending signal, zero if not. - */ -int block_signals(void); /* Returns non zero if signal pending */ - #ifdef TARGET_I386 /* vm86.c */ void save_v86_state(CPUX86State *env); diff --git a/linux-user/riscv/cpu_loop.c b/linux-user/riscv/cpu_loop.c index 74a9628dc9..47978c4e35 100644 --- a/linux-user/riscv/cpu_loop.c +++ b/linux-user/riscv/cpu_loop.c @@ -22,6 +22,7 @@ #include "qemu/error-report.h" #include "qemu.h" #include "cpu_loop-common.h" +#include "signal-common.h" #include "elf.h" #include "semihosting/common-semi.h" diff --git a/linux-user/s390x/cpu_loop.c b/linux-user/s390x/cpu_loop.c index 6a69a6dd26..ae70f63053 100644 --- a/linux-user/s390x/cpu_loop.c +++ b/linux-user/s390x/cpu_loop.c @@ -21,6 +21,7 @@ #include "qemu-common.h" #include "qemu.h" #include "cpu_loop-common.h" +#include "signal-common.h" /* s390x masks the fault address it reports in si_addr for SIGSEGV and SIGBUS */ #define S390X_FAIL_ADDR_MASK -4096LL diff --git a/linux-user/sh4/cpu_loop.c b/linux-user/sh4/cpu_loop.c index 222ed1c670..06e4a4d007 100644 --- a/linux-user/sh4/cpu_loop.c +++ b/linux-user/sh4/cpu_loop.c @@ -21,6 +21,7 @@ #include "qemu-common.h" #include "qemu.h" #include "cpu_loop-common.h" +#include "signal-common.h" void cpu_loop(CPUSH4State *env) { diff --git a/linux-user/signal-common.h b/linux-user/signal-common.h index ea86328b28..58ea23f6ea 100644 --- a/linux-user/signal-common.h +++ b/linux-user/signal-common.h @@ -47,4 +47,40 @@ void setup_frame(int sig, struct target_sigaction *ka, void setup_rt_frame(int sig, struct target_sigaction *ka, target_siginfo_t *info, target_sigset_t *set, CPUArchState *env); + +void process_pending_signals(CPUArchState *cpu_env); +void signal_init(void); +int queue_signal(CPUArchState *env, int sig, int si_type, + target_siginfo_t *info); +void host_to_target_siginfo(target_siginfo_t *tinfo, const siginfo_t *info); +void target_to_host_siginfo(siginfo_t *info, const target_siginfo_t *tinfo); +int target_to_host_signal(int sig); +int host_to_target_signal(int sig); +long do_sigreturn(CPUArchState *env); +long do_rt_sigreturn(CPUArchState *env); +abi_long do_sigaltstack(abi_ulong uss_addr, abi_ulong uoss_addr, + CPUArchState *env); +int do_sigprocmask(int how, const sigset_t *set, sigset_t *oldset); +abi_long do_swapcontext(CPUArchState *env, abi_ulong uold_ctx, + abi_ulong unew_ctx, abi_long ctx_size); +/** + * block_signals: block all signals while handling this guest syscall + * + * Block all signals, and arrange that the signal mask is returned to + * its correct value for the guest before we resume execution of guest code. + * If this function returns non-zero, then the caller should immediately + * return -TARGET_ERESTARTSYS to the main loop, which will take the pending + * signal and restart execution of the syscall. + * If block_signals() returns zero, then the caller can continue with + * emulation of the system call knowing that no signals can be taken + * (and therefore that no race conditions will result). + * This should only be called once, because if it is called a second time + * it will always return non-zero. (Think of it like a mutex that can't + * be recursively locked.) + * Signals will be unblocked again by process_pending_signals(). + * + * Return value: non-zero if there was a pending signal, zero if not. + */ +int block_signals(void); /* Returns non zero if signal pending */ + #endif diff --git a/linux-user/sparc/cpu_loop.c b/linux-user/sparc/cpu_loop.c index 02532f198d..b2c0611194 100644 --- a/linux-user/sparc/cpu_loop.c +++ b/linux-user/sparc/cpu_loop.c @@ -21,6 +21,7 @@ #include "qemu-common.h" #include "qemu.h" #include "cpu_loop-common.h" +#include "signal-common.h" #define SPARC64_STACK_BIAS 2047 diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 4ac2801e49..ad635ed3a5 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -128,6 +128,7 @@ #include "qemu.h" #include "strace.h" +#include "signal-common.h" #include "qemu/guest-random.h" #include "qemu/selfmap.h" #include "user/syscall-trace.h" diff --git a/linux-user/xtensa/cpu_loop.c b/linux-user/xtensa/cpu_loop.c index 64831c9199..bb5335e2b6 100644 --- a/linux-user/xtensa/cpu_loop.c +++ b/linux-user/xtensa/cpu_loop.c @@ -20,6 +20,7 @@ #include "qemu/osdep.h" #include "qemu.h" #include "cpu_loop-common.h" +#include "signal-common.h" static void xtensa_rfw(CPUXtensaState *env) { From 3ad0a76928df01726e5872b8530d8e1eaa1a971d Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Wed, 8 Sep 2021 16:44:00 +0100 Subject: [PATCH 04/10] linux-user: Split loader-related prototypes into loader.h MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Split guest-binary loader prototypes out into a new header loader.h which we include only where required. Signed-off-by: Peter Maydell Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Richard Henderson Message-Id: <20210908154405.15417-5-peter.maydell@linaro.org> Signed-off-by: Laurent Vivier --- linux-user/elfload.c | 1 + linux-user/flatload.c | 1 + linux-user/linuxload.c | 1 + linux-user/loader.h | 59 ++++++++++++++++++++++++++++++++++++++++++ linux-user/main.c | 1 + linux-user/qemu.h | 40 ---------------------------- linux-user/signal.c | 1 + linux-user/syscall.c | 1 + 8 files changed, 65 insertions(+), 40 deletions(-) create mode 100644 linux-user/loader.h diff --git a/linux-user/elfload.c b/linux-user/elfload.c index 01e9a833fb..6244fcd05c 100644 --- a/linux-user/elfload.c +++ b/linux-user/elfload.c @@ -6,6 +6,7 @@ #include #include "qemu.h" +#include "loader.h" #include "disas/disas.h" #include "qemu/bitops.h" #include "qemu/path.h" diff --git a/linux-user/flatload.c b/linux-user/flatload.c index 3e5594cf89..7484a4a354 100644 --- a/linux-user/flatload.c +++ b/linux-user/flatload.c @@ -36,6 +36,7 @@ #include "qemu/osdep.h" #include "qemu.h" +#include "loader.h" #include "flat.h" #include "target_flat.h" diff --git a/linux-user/linuxload.c b/linux-user/linuxload.c index 9d4eb5e94b..27be7090d8 100644 --- a/linux-user/linuxload.c +++ b/linux-user/linuxload.c @@ -2,6 +2,7 @@ #include "qemu/osdep.h" #include "qemu.h" +#include "loader.h" #define NGROUPS 32 diff --git a/linux-user/loader.h b/linux-user/loader.h new file mode 100644 index 0000000000..f375ee0679 --- /dev/null +++ b/linux-user/loader.h @@ -0,0 +1,59 @@ +/* + * loader.h: prototypes for linux-user guest binary loader + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see . + */ + +#ifndef LINUX_USER_LOADER_H +#define LINUX_USER_LOADER_H + +/* + * Read a good amount of data initially, to hopefully get all the + * program headers loaded. + */ +#define BPRM_BUF_SIZE 1024 + +/* + * This structure is used to hold the arguments that are + * used when loading binaries. + */ +struct linux_binprm { + char buf[BPRM_BUF_SIZE] __attribute__((aligned)); + abi_ulong p; + int fd; + int e_uid, e_gid; + int argc, envc; + char **argv; + char **envp; + char *filename; /* Name of binary */ + int (*core_dump)(int, const CPUArchState *); /* coredump routine */ +}; + +void do_init_thread(struct target_pt_regs *regs, struct image_info *infop); +abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp, + abi_ulong stringp, int push_ptr); +int loader_exec(int fdexec, const char *filename, char **argv, char **envp, + struct target_pt_regs *regs, struct image_info *infop, + struct linux_binprm *); + +uint32_t get_elf_eflags(int fd); +int load_elf_binary(struct linux_binprm *bprm, struct image_info *info); +int load_flt_binary(struct linux_binprm *bprm, struct image_info *info); + +abi_long memcpy_to_target(abi_ulong dest, const void *src, + unsigned long len); + +extern unsigned long guest_stack_size; + +#endif /* LINUX_USER_LOADER_H */ diff --git a/linux-user/main.c b/linux-user/main.c index 4f51670735..67c5a87ffa 100644 --- a/linux-user/main.c +++ b/linux-user/main.c @@ -50,6 +50,7 @@ #include "crypto/init.h" #include "fd-trans.h" #include "signal-common.h" +#include "loader.h" #ifndef AT_FLAGS_PRESERVE_ARGV0 #define AT_FLAGS_PRESERVE_ARGV0_BIT 0 diff --git a/linux-user/qemu.h b/linux-user/qemu.h index 76d3f5e7eb..02c4778c97 100644 --- a/linux-user/qemu.h +++ b/linux-user/qemu.h @@ -173,30 +173,6 @@ void stop_all_tasks(void); extern const char *qemu_uname_release; extern unsigned long mmap_min_addr; -/* ??? See if we can avoid exposing so much of the loader internals. */ - -/* - * Read a good amount of data initially, to hopefully get all the - * program headers loaded. - */ -#define BPRM_BUF_SIZE 1024 - -/* - * This structure is used to hold the arguments that are - * used when loading binaries. - */ -struct linux_binprm { - char buf[BPRM_BUF_SIZE] __attribute__((aligned)); - abi_ulong p; - int fd; - int e_uid, e_gid; - int argc, envc; - char **argv; - char **envp; - char *filename; /* Name of binary */ - int (*core_dump)(int, const CPUArchState *); /* coredump routine */ -}; - typedef struct IOCTLEntry IOCTLEntry; typedef abi_long do_ioctl_fn(const IOCTLEntry *ie, uint8_t *buf_temp, @@ -217,13 +193,6 @@ extern IOCTLEntry ioctl_entries[]; #define IOC_W 0x0002 #define IOC_RW (IOC_R | IOC_W) -void do_init_thread(struct target_pt_regs *regs, struct image_info *infop); -abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp, - abi_ulong stringp, int push_ptr); -int loader_exec(int fdexec, const char *filename, char **argv, char **envp, - struct target_pt_regs *regs, struct image_info *infop, - struct linux_binprm *); - /* * Returns true if the image uses the FDPIC ABI. If this is the case, * we have to provide some information (loadmap, pt_dynamic_info) such @@ -232,12 +201,6 @@ int loader_exec(int fdexec, const char *filename, char **argv, char **envp, */ int info_is_fdpic(struct image_info *info); -uint32_t get_elf_eflags(int fd); -int load_elf_binary(struct linux_binprm *bprm, struct image_info *info); -int load_flt_binary(struct linux_binprm *bprm, struct image_info *info); - -abi_long memcpy_to_target(abi_ulong dest, const void *src, - unsigned long len); void target_set_brk(abi_ulong new_brk); abi_long do_brk(abi_ulong new_brk); void syscall_init(void); @@ -440,9 +403,6 @@ abi_ulong mmap_find_vma(abi_ulong, abi_ulong, abi_ulong); void mmap_fork_start(void); void mmap_fork_end(int child); -/* main.c */ -extern unsigned long guest_stack_size; - /* user access */ #define VERIFY_READ PAGE_READ diff --git a/linux-user/signal.c b/linux-user/signal.c index ee1934947a..0fa15f088b 100644 --- a/linux-user/signal.c +++ b/linux-user/signal.c @@ -23,6 +23,7 @@ #include "qemu.h" #include "strace.h" +#include "loader.h" #include "trace.h" #include "signal-common.h" diff --git a/linux-user/syscall.c b/linux-user/syscall.c index ad635ed3a5..b1cd7410d8 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -129,6 +129,7 @@ #include "qemu.h" #include "strace.h" #include "signal-common.h" +#include "loader.h" #include "qemu/guest-random.h" #include "qemu/selfmap.h" #include "user/syscall-trace.h" From 5423e6d3a416342ee5857d02688c30b776574b66 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Wed, 8 Sep 2021 16:44:01 +0100 Subject: [PATCH 05/10] linux-user: Split mmap prototypes into user-mmap.h MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Split out the mmap prototypes into a new header user-mmap.h which we only include where required. Signed-off-by: Peter Maydell Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Richard Henderson Message-Id: <20210908154405.15417-6-peter.maydell@linaro.org> Signed-off-by: Laurent Vivier --- linux-user/elfload.c | 1 + linux-user/flatload.c | 1 + linux-user/i386/cpu_loop.c | 1 + linux-user/main.c | 1 + linux-user/mmap.c | 1 + linux-user/qemu.h | 14 -------------- linux-user/syscall.c | 1 + linux-user/user-mmap.h | 34 ++++++++++++++++++++++++++++++++++ 8 files changed, 40 insertions(+), 14 deletions(-) create mode 100644 linux-user/user-mmap.h diff --git a/linux-user/elfload.c b/linux-user/elfload.c index 6244fcd05c..c291f3cee0 100644 --- a/linux-user/elfload.c +++ b/linux-user/elfload.c @@ -7,6 +7,7 @@ #include "qemu.h" #include "loader.h" +#include "user-mmap.h" #include "disas/disas.h" #include "qemu/bitops.h" #include "qemu/path.h" diff --git a/linux-user/flatload.c b/linux-user/flatload.c index 7484a4a354..99550061db 100644 --- a/linux-user/flatload.c +++ b/linux-user/flatload.c @@ -37,6 +37,7 @@ #include "qemu.h" #include "loader.h" +#include "user-mmap.h" #include "flat.h" #include "target_flat.h" diff --git a/linux-user/i386/cpu_loop.c b/linux-user/i386/cpu_loop.c index ee2e139a06..fcc410a426 100644 --- a/linux-user/i386/cpu_loop.c +++ b/linux-user/i386/cpu_loop.c @@ -22,6 +22,7 @@ #include "qemu.h" #include "cpu_loop-common.h" #include "signal-common.h" +#include "user-mmap.h" /***********************************************************/ /* CPUX86 core interface */ diff --git a/linux-user/main.c b/linux-user/main.c index 67c5a87ffa..a76aec7336 100644 --- a/linux-user/main.c +++ b/linux-user/main.c @@ -51,6 +51,7 @@ #include "fd-trans.h" #include "signal-common.h" #include "loader.h" +#include "user-mmap.h" #ifndef AT_FLAGS_PRESERVE_ARGV0 #define AT_FLAGS_PRESERVE_ARGV0_BIT 0 diff --git a/linux-user/mmap.c b/linux-user/mmap.c index 0e103859fe..4b182444bb 100644 --- a/linux-user/mmap.c +++ b/linux-user/mmap.c @@ -20,6 +20,7 @@ #include "trace.h" #include "exec/log.h" #include "qemu.h" +#include "user-mmap.h" static pthread_mutex_t mmap_mutex = PTHREAD_MUTEX_INITIALIZER; static __thread int mmap_lock_count; diff --git a/linux-user/qemu.h b/linux-user/qemu.h index 02c4778c97..0cb7999057 100644 --- a/linux-user/qemu.h +++ b/linux-user/qemu.h @@ -389,20 +389,6 @@ void sparc64_set_context(CPUSPARCState *env); void sparc64_get_context(CPUSPARCState *env); #endif -/* mmap.c */ -int target_mprotect(abi_ulong start, abi_ulong len, int prot); -abi_long target_mmap(abi_ulong start, abi_ulong len, int prot, - int flags, int fd, abi_ulong offset); -int target_munmap(abi_ulong start, abi_ulong len); -abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size, - abi_ulong new_size, unsigned long flags, - abi_ulong new_addr); -extern unsigned long last_brk; -extern abi_ulong mmap_next_start; -abi_ulong mmap_find_vma(abi_ulong, abi_ulong, abi_ulong); -void mmap_fork_start(void); -void mmap_fork_end(int child); - /* user access */ #define VERIFY_READ PAGE_READ diff --git a/linux-user/syscall.c b/linux-user/syscall.c index b1cd7410d8..b6c8406e1d 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -130,6 +130,7 @@ #include "strace.h" #include "signal-common.h" #include "loader.h" +#include "user-mmap.h" #include "qemu/guest-random.h" #include "qemu/selfmap.h" #include "user/syscall-trace.h" diff --git a/linux-user/user-mmap.h b/linux-user/user-mmap.h new file mode 100644 index 0000000000..d1dec99c02 --- /dev/null +++ b/linux-user/user-mmap.h @@ -0,0 +1,34 @@ +/* + * user-mmap.h: prototypes for linux-user guest binary loader + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see . + */ + +#ifndef LINUX_USER_USER_MMAP_H +#define LINUX_USER_USER_MMAP_H + +int target_mprotect(abi_ulong start, abi_ulong len, int prot); +abi_long target_mmap(abi_ulong start, abi_ulong len, int prot, + int flags, int fd, abi_ulong offset); +int target_munmap(abi_ulong start, abi_ulong len); +abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size, + abi_ulong new_size, unsigned long flags, + abi_ulong new_addr); +extern unsigned long last_brk; +extern abi_ulong mmap_next_start; +abi_ulong mmap_find_vma(abi_ulong, abi_ulong, abi_ulong); +void mmap_fork_start(void); +void mmap_fork_end(int child); + +#endif /* LINUX_USER_USER_MMAP_H */ From a57e0c3657b764fa0311ffca2c72bd8dcd39e8af Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Wed, 8 Sep 2021 16:44:02 +0100 Subject: [PATCH 06/10] linux-user: Split safe-syscall macro into its own header MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Split the safe-syscall macro from qemu.h into a new safe-syscall.h. Signed-off-by: Peter Maydell Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Richard Henderson Message-Id: <20210908154405.15417-7-peter.maydell@linaro.org> Signed-off-by: Laurent Vivier --- linux-user/qemu.h | 135 --------------------------------- linux-user/safe-syscall.h | 154 ++++++++++++++++++++++++++++++++++++++ linux-user/syscall.c | 1 + 3 files changed, 155 insertions(+), 135 deletions(-) create mode 100644 linux-user/safe-syscall.h diff --git a/linux-user/qemu.h b/linux-user/qemu.h index 0cb7999057..a82a46236e 100644 --- a/linux-user/qemu.h +++ b/linux-user/qemu.h @@ -240,141 +240,6 @@ void probe_guest_base(const char *image_name, #include "qemu/log.h" -/* safe_syscall.S */ - -/** - * safe_syscall: - * @int number: number of system call to make - * ...: arguments to the system call - * - * Call a system call if guest signal not pending. - * This has the same API as the libc syscall() function, except that it - * may return -1 with errno == TARGET_ERESTARTSYS if a signal was pending. - * - * Returns: the system call result, or -1 with an error code in errno - * (Errnos are host errnos; we rely on TARGET_ERESTARTSYS not clashing - * with any of the host errno values.) - */ - -/* - * A guide to using safe_syscall() to handle interactions between guest - * syscalls and guest signals: - * - * Guest syscalls come in two flavours: - * - * (1) Non-interruptible syscalls - * - * These are guest syscalls that never get interrupted by signals and - * so never return EINTR. They can be implemented straightforwardly in - * QEMU: just make sure that if the implementation code has to make any - * blocking calls that those calls are retried if they return EINTR. - * It's also OK to implement these with safe_syscall, though it will be - * a little less efficient if a signal is delivered at the 'wrong' moment. - * - * Some non-interruptible syscalls need to be handled using block_signals() - * to block signals for the duration of the syscall. This mainly applies - * to code which needs to modify the data structures used by the - * host_signal_handler() function and the functions it calls, including - * all syscalls which change the thread's signal mask. - * - * (2) Interruptible syscalls - * - * These are guest syscalls that can be interrupted by signals and - * for which we need to either return EINTR or arrange for the guest - * syscall to be restarted. This category includes both syscalls which - * always restart (and in the kernel return -ERESTARTNOINTR), ones - * which only restart if there is no handler (kernel returns -ERESTARTNOHAND - * or -ERESTART_RESTARTBLOCK), and the most common kind which restart - * if the handler was registered with SA_RESTART (kernel returns - * -ERESTARTSYS). System calls which are only interruptible in some - * situations (like 'open') also need to be handled this way. - * - * Here it is important that the host syscall is made - * via this safe_syscall() function, and *not* via the host libc. - * If the host libc is used then the implementation will appear to work - * most of the time, but there will be a race condition where a - * signal could arrive just before we make the host syscall inside libc, - * and then then guest syscall will not correctly be interrupted. - * Instead the implementation of the guest syscall can use the safe_syscall - * function but otherwise just return the result or errno in the usual - * way; the main loop code will take care of restarting the syscall - * if appropriate. - * - * (If the implementation needs to make multiple host syscalls this is - * OK; any which might really block must be via safe_syscall(); for those - * which are only technically blocking (ie which we know in practice won't - * stay in the host kernel indefinitely) it's OK to use libc if necessary. - * You must be able to cope with backing out correctly if some safe_syscall - * you make in the implementation returns either -TARGET_ERESTARTSYS or - * EINTR though.) - * - * block_signals() cannot be used for interruptible syscalls. - * - * - * How and why the safe_syscall implementation works: - * - * The basic setup is that we make the host syscall via a known - * section of host native assembly. If a signal occurs, our signal - * handler checks the interrupted host PC against the addresse of that - * known section. If the PC is before or at the address of the syscall - * instruction then we change the PC to point at a "return - * -TARGET_ERESTARTSYS" code path instead, and then exit the signal handler - * (causing the safe_syscall() call to immediately return that value). - * Then in the main.c loop if we see this magic return value we adjust - * the guest PC to wind it back to before the system call, and invoke - * the guest signal handler as usual. - * - * This winding-back will happen in two cases: - * (1) signal came in just before we took the host syscall (a race); - * in this case we'll take the guest signal and have another go - * at the syscall afterwards, and this is indistinguishable for the - * guest from the timing having been different such that the guest - * signal really did win the race - * (2) signal came in while the host syscall was blocking, and the - * host kernel decided the syscall should be restarted; - * in this case we want to restart the guest syscall also, and so - * rewinding is the right thing. (Note that "restart" semantics mean - * "first call the signal handler, then reattempt the syscall".) - * The other situation to consider is when a signal came in while the - * host syscall was blocking, and the host kernel decided that the syscall - * should not be restarted; in this case QEMU's host signal handler will - * be invoked with the PC pointing just after the syscall instruction, - * with registers indicating an EINTR return; the special code in the - * handler will not kick in, and we will return EINTR to the guest as - * we should. - * - * Notice that we can leave the host kernel to make the decision for - * us about whether to do a restart of the syscall or not; we do not - * need to check SA_RESTART flags in QEMU or distinguish the various - * kinds of restartability. - */ -#ifdef HAVE_SAFE_SYSCALL -/* The core part of this function is implemented in assembly */ -extern long safe_syscall_base(int *pending, long number, ...); - -#define safe_syscall(...) \ - ({ \ - long ret_; \ - int *psp_ = &((TaskState *)thread_cpu->opaque)->signal_pending; \ - ret_ = safe_syscall_base(psp_, __VA_ARGS__); \ - if (is_error(ret_)) { \ - errno = -ret_; \ - ret_ = -1; \ - } \ - ret_; \ - }) - -#else - -/* - * Fallback for architectures which don't yet provide a safe-syscall assembly - * fragment; note that this is racy! - * This should go away when all host architectures have been updated. - */ -#define safe_syscall syscall - -#endif - /* syscall.c */ int host_to_target_waitstatus(int status); diff --git a/linux-user/safe-syscall.h b/linux-user/safe-syscall.h new file mode 100644 index 0000000000..6bc0390262 --- /dev/null +++ b/linux-user/safe-syscall.h @@ -0,0 +1,154 @@ +/* + * safe-syscall.h: prototypes for linux-user signal-race-safe syscalls + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see . + */ + +#ifndef LINUX_USER_SAFE_SYSCALL_H +#define LINUX_USER_SAFE_SYSCALL_H + +/** + * safe_syscall: + * @int number: number of system call to make + * ...: arguments to the system call + * + * Call a system call if guest signal not pending. + * This has the same API as the libc syscall() function, except that it + * may return -1 with errno == TARGET_ERESTARTSYS if a signal was pending. + * + * Returns: the system call result, or -1 with an error code in errno + * (Errnos are host errnos; we rely on TARGET_ERESTARTSYS not clashing + * with any of the host errno values.) + */ + +/* + * A guide to using safe_syscall() to handle interactions between guest + * syscalls and guest signals: + * + * Guest syscalls come in two flavours: + * + * (1) Non-interruptible syscalls + * + * These are guest syscalls that never get interrupted by signals and + * so never return EINTR. They can be implemented straightforwardly in + * QEMU: just make sure that if the implementation code has to make any + * blocking calls that those calls are retried if they return EINTR. + * It's also OK to implement these with safe_syscall, though it will be + * a little less efficient if a signal is delivered at the 'wrong' moment. + * + * Some non-interruptible syscalls need to be handled using block_signals() + * to block signals for the duration of the syscall. This mainly applies + * to code which needs to modify the data structures used by the + * host_signal_handler() function and the functions it calls, including + * all syscalls which change the thread's signal mask. + * + * (2) Interruptible syscalls + * + * These are guest syscalls that can be interrupted by signals and + * for which we need to either return EINTR or arrange for the guest + * syscall to be restarted. This category includes both syscalls which + * always restart (and in the kernel return -ERESTARTNOINTR), ones + * which only restart if there is no handler (kernel returns -ERESTARTNOHAND + * or -ERESTART_RESTARTBLOCK), and the most common kind which restart + * if the handler was registered with SA_RESTART (kernel returns + * -ERESTARTSYS). System calls which are only interruptible in some + * situations (like 'open') also need to be handled this way. + * + * Here it is important that the host syscall is made + * via this safe_syscall() function, and *not* via the host libc. + * If the host libc is used then the implementation will appear to work + * most of the time, but there will be a race condition where a + * signal could arrive just before we make the host syscall inside libc, + * and then then guest syscall will not correctly be interrupted. + * Instead the implementation of the guest syscall can use the safe_syscall + * function but otherwise just return the result or errno in the usual + * way; the main loop code will take care of restarting the syscall + * if appropriate. + * + * (If the implementation needs to make multiple host syscalls this is + * OK; any which might really block must be via safe_syscall(); for those + * which are only technically blocking (ie which we know in practice won't + * stay in the host kernel indefinitely) it's OK to use libc if necessary. + * You must be able to cope with backing out correctly if some safe_syscall + * you make in the implementation returns either -TARGET_ERESTARTSYS or + * EINTR though.) + * + * block_signals() cannot be used for interruptible syscalls. + * + * + * How and why the safe_syscall implementation works: + * + * The basic setup is that we make the host syscall via a known + * section of host native assembly. If a signal occurs, our signal + * handler checks the interrupted host PC against the addresse of that + * known section. If the PC is before or at the address of the syscall + * instruction then we change the PC to point at a "return + * -TARGET_ERESTARTSYS" code path instead, and then exit the signal handler + * (causing the safe_syscall() call to immediately return that value). + * Then in the main.c loop if we see this magic return value we adjust + * the guest PC to wind it back to before the system call, and invoke + * the guest signal handler as usual. + * + * This winding-back will happen in two cases: + * (1) signal came in just before we took the host syscall (a race); + * in this case we'll take the guest signal and have another go + * at the syscall afterwards, and this is indistinguishable for the + * guest from the timing having been different such that the guest + * signal really did win the race + * (2) signal came in while the host syscall was blocking, and the + * host kernel decided the syscall should be restarted; + * in this case we want to restart the guest syscall also, and so + * rewinding is the right thing. (Note that "restart" semantics mean + * "first call the signal handler, then reattempt the syscall".) + * The other situation to consider is when a signal came in while the + * host syscall was blocking, and the host kernel decided that the syscall + * should not be restarted; in this case QEMU's host signal handler will + * be invoked with the PC pointing just after the syscall instruction, + * with registers indicating an EINTR return; the special code in the + * handler will not kick in, and we will return EINTR to the guest as + * we should. + * + * Notice that we can leave the host kernel to make the decision for + * us about whether to do a restart of the syscall or not; we do not + * need to check SA_RESTART flags in QEMU or distinguish the various + * kinds of restartability. + */ +#ifdef HAVE_SAFE_SYSCALL +/* The core part of this function is implemented in assembly */ +extern long safe_syscall_base(int *pending, long number, ...); + +#define safe_syscall(...) \ + ({ \ + long ret_; \ + int *psp_ = &((TaskState *)thread_cpu->opaque)->signal_pending; \ + ret_ = safe_syscall_base(psp_, __VA_ARGS__); \ + if (is_error(ret_)) { \ + errno = -ret_; \ + ret_ = -1; \ + } \ + ret_; \ + }) + +#else + +/* + * Fallback for architectures which don't yet provide a safe-syscall assembly + * fragment; note that this is racy! + * This should go away when all host architectures have been updated. + */ +#define safe_syscall syscall + +#endif + +#endif diff --git a/linux-user/syscall.c b/linux-user/syscall.c index b6c8406e1d..9873830b46 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -131,6 +131,7 @@ #include "signal-common.h" #include "loader.h" #include "user-mmap.h" +#include "safe-syscall.h" #include "qemu/guest-random.h" #include "qemu/selfmap.h" #include "user/syscall-trace.h" From 3b249d2661c752e75ef6d2d4ac63bdf9a921dd4b Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Wed, 8 Sep 2021 16:44:03 +0100 Subject: [PATCH 07/10] linux-user: Split linux-user internals out of qemu.h qemu.h is included in various non-linux-user files (which mostly want the TaskState struct and the functions for doing usermode access to guest addresses like lock_user(), unlock_user(), get_user*(), etc). Split out the parts that are only used in linux-user itself into a new user-internals.h. This leaves qemu.h with basically three things: * the definition of the TaskState struct * the user-access functions and macros * do_brk() all of which are needed by code outside linux-user that includes qemu.h. The addition of all the extra #include lines was done with sed -i '/include.*qemu\.h/a #include "user-internals.h"' $(git grep -l 'include.*qemu\.h' linux-user) (and then undoing the change to fpa11.h). Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-Id: <20210908154405.15417-8-peter.maydell@linaro.org> Signed-off-by: Laurent Vivier --- linux-user/aarch64/cpu_loop.c | 1 + linux-user/aarch64/signal.c | 1 + linux-user/alpha/cpu_loop.c | 1 + linux-user/alpha/signal.c | 1 + linux-user/arm/cpu_loop.c | 1 + linux-user/arm/signal.c | 1 + linux-user/cris/cpu_loop.c | 1 + linux-user/cris/signal.c | 1 + linux-user/elfload.c | 1 + linux-user/exit.c | 1 + linux-user/fd-trans.c | 1 + linux-user/flatload.c | 1 + linux-user/hexagon/cpu_loop.c | 1 + linux-user/hexagon/signal.c | 1 + linux-user/hppa/cpu_loop.c | 1 + linux-user/hppa/signal.c | 1 + linux-user/i386/cpu_loop.c | 1 + linux-user/i386/signal.c | 1 + linux-user/linuxload.c | 1 + linux-user/m68k/cpu_loop.c | 1 + linux-user/m68k/signal.c | 1 + linux-user/main.c | 1 + linux-user/microblaze/cpu_loop.c | 1 + linux-user/microblaze/signal.c | 1 + linux-user/mips/cpu_loop.c | 1 + linux-user/mips/signal.c | 1 + linux-user/mmap.c | 1 + linux-user/nios2/cpu_loop.c | 1 + linux-user/nios2/signal.c | 1 + linux-user/openrisc/cpu_loop.c | 1 + linux-user/openrisc/signal.c | 1 + linux-user/ppc/cpu_loop.c | 1 + linux-user/ppc/signal.c | 1 + linux-user/qemu.h | 164 +-------------------------- linux-user/riscv/cpu_loop.c | 1 + linux-user/riscv/signal.c | 1 + linux-user/s390x/cpu_loop.c | 1 + linux-user/s390x/signal.c | 1 + linux-user/semihost.c | 1 + linux-user/sh4/cpu_loop.c | 1 + linux-user/sh4/signal.c | 1 + linux-user/signal.c | 1 + linux-user/sparc/cpu_loop.c | 1 + linux-user/sparc/signal.c | 1 + linux-user/strace.c | 1 + linux-user/syscall.c | 1 + linux-user/uaccess.c | 1 + linux-user/uname.c | 1 + linux-user/user-internals.h | 184 +++++++++++++++++++++++++++++++ linux-user/vm86.c | 1 + linux-user/xtensa/cpu_loop.c | 1 + linux-user/xtensa/signal.c | 1 + 52 files changed, 235 insertions(+), 163 deletions(-) create mode 100644 linux-user/user-internals.h diff --git a/linux-user/aarch64/cpu_loop.c b/linux-user/aarch64/cpu_loop.c index 5cac76f67b..5425b85659 100644 --- a/linux-user/aarch64/cpu_loop.c +++ b/linux-user/aarch64/cpu_loop.c @@ -20,6 +20,7 @@ #include "qemu/osdep.h" #include "qemu-common.h" #include "qemu.h" +#include "user-internals.h" #include "cpu_loop-common.h" #include "signal-common.h" #include "qemu/guest-random.h" diff --git a/linux-user/aarch64/signal.c b/linux-user/aarch64/signal.c index 662bcd1c4e..49025648cb 100644 --- a/linux-user/aarch64/signal.c +++ b/linux-user/aarch64/signal.c @@ -18,6 +18,7 @@ */ #include "qemu/osdep.h" #include "qemu.h" +#include "user-internals.h" #include "signal-common.h" #include "linux-user/trace.h" diff --git a/linux-user/alpha/cpu_loop.c b/linux-user/alpha/cpu_loop.c index 8464047368..1b00a81385 100644 --- a/linux-user/alpha/cpu_loop.c +++ b/linux-user/alpha/cpu_loop.c @@ -20,6 +20,7 @@ #include "qemu/osdep.h" #include "qemu-common.h" #include "qemu.h" +#include "user-internals.h" #include "cpu_loop-common.h" #include "signal-common.h" diff --git a/linux-user/alpha/signal.c b/linux-user/alpha/signal.c index 1129ffeea1..3a820f616b 100644 --- a/linux-user/alpha/signal.c +++ b/linux-user/alpha/signal.c @@ -18,6 +18,7 @@ */ #include "qemu/osdep.h" #include "qemu.h" +#include "user-internals.h" #include "signal-common.h" #include "linux-user/trace.h" diff --git a/linux-user/arm/cpu_loop.c b/linux-user/arm/cpu_loop.c index 5556d38146..07032b3006 100644 --- a/linux-user/arm/cpu_loop.c +++ b/linux-user/arm/cpu_loop.c @@ -20,6 +20,7 @@ #include "qemu/osdep.h" #include "qemu-common.h" #include "qemu.h" +#include "user-internals.h" #include "elf.h" #include "cpu_loop-common.h" #include "signal-common.h" diff --git a/linux-user/arm/signal.c b/linux-user/arm/signal.c index 1dfcfd2d57..ed144f9455 100644 --- a/linux-user/arm/signal.c +++ b/linux-user/arm/signal.c @@ -18,6 +18,7 @@ */ #include "qemu/osdep.h" #include "qemu.h" +#include "user-internals.h" #include "signal-common.h" #include "linux-user/trace.h" diff --git a/linux-user/cris/cpu_loop.c b/linux-user/cris/cpu_loop.c index 8c9fc3127e..b9085619c4 100644 --- a/linux-user/cris/cpu_loop.c +++ b/linux-user/cris/cpu_loop.c @@ -20,6 +20,7 @@ #include "qemu/osdep.h" #include "qemu-common.h" #include "qemu.h" +#include "user-internals.h" #include "cpu_loop-common.h" #include "signal-common.h" diff --git a/linux-user/cris/signal.c b/linux-user/cris/signal.c index 1e02194377..2c39bdf727 100644 --- a/linux-user/cris/signal.c +++ b/linux-user/cris/signal.c @@ -18,6 +18,7 @@ */ #include "qemu/osdep.h" #include "qemu.h" +#include "user-internals.h" #include "signal-common.h" #include "linux-user/trace.h" diff --git a/linux-user/elfload.c b/linux-user/elfload.c index c291f3cee0..5f9e2141ad 100644 --- a/linux-user/elfload.c +++ b/linux-user/elfload.c @@ -6,6 +6,7 @@ #include #include "qemu.h" +#include "user-internals.h" #include "loader.h" #include "user-mmap.h" #include "disas/disas.h" diff --git a/linux-user/exit.c b/linux-user/exit.c index 527e29cbc1..68a3a6f9df 100644 --- a/linux-user/exit.c +++ b/linux-user/exit.c @@ -18,6 +18,7 @@ */ #include "qemu/osdep.h" #include "qemu.h" +#include "user-internals.h" #ifdef CONFIG_GPROF #include #endif diff --git a/linux-user/fd-trans.c b/linux-user/fd-trans.c index 48203c1af9..6941089959 100644 --- a/linux-user/fd-trans.c +++ b/linux-user/fd-trans.c @@ -27,6 +27,7 @@ #include #endif #include "qemu.h" +#include "user-internals.h" #include "fd-trans.h" #include "signal-common.h" diff --git a/linux-user/flatload.c b/linux-user/flatload.c index 99550061db..e4c2f89a22 100644 --- a/linux-user/flatload.c +++ b/linux-user/flatload.c @@ -36,6 +36,7 @@ #include "qemu/osdep.h" #include "qemu.h" +#include "user-internals.h" #include "loader.h" #include "user-mmap.h" #include "flat.h" diff --git a/linux-user/hexagon/cpu_loop.c b/linux-user/hexagon/cpu_loop.c index 348d2dc341..bee2a9e4ea 100644 --- a/linux-user/hexagon/cpu_loop.c +++ b/linux-user/hexagon/cpu_loop.c @@ -20,6 +20,7 @@ #include "qemu/osdep.h" #include "qemu.h" +#include "user-internals.h" #include "cpu_loop-common.h" #include "signal-common.h" #include "internal.h" diff --git a/linux-user/hexagon/signal.c b/linux-user/hexagon/signal.c index 85eab5e943..c7f0bf6b92 100644 --- a/linux-user/hexagon/signal.c +++ b/linux-user/hexagon/signal.c @@ -19,6 +19,7 @@ */ #include "qemu/osdep.h" #include "qemu.h" +#include "user-internals.h" #include "signal-common.h" #include "linux-user/trace.h" diff --git a/linux-user/hppa/cpu_loop.c b/linux-user/hppa/cpu_loop.c index c3661994a5..81607a9b27 100644 --- a/linux-user/hppa/cpu_loop.c +++ b/linux-user/hppa/cpu_loop.c @@ -19,6 +19,7 @@ #include "qemu/osdep.h" #include "qemu.h" +#include "user-internals.h" #include "cpu_loop-common.h" #include "signal-common.h" diff --git a/linux-user/hppa/signal.c b/linux-user/hppa/signal.c index 0e266f472d..c2fbc26ebb 100644 --- a/linux-user/hppa/signal.c +++ b/linux-user/hppa/signal.c @@ -18,6 +18,7 @@ */ #include "qemu/osdep.h" #include "qemu.h" +#include "user-internals.h" #include "signal-common.h" #include "linux-user/trace.h" diff --git a/linux-user/i386/cpu_loop.c b/linux-user/i386/cpu_loop.c index fcc410a426..f6a1cc632b 100644 --- a/linux-user/i386/cpu_loop.c +++ b/linux-user/i386/cpu_loop.c @@ -20,6 +20,7 @@ #include "qemu/osdep.h" #include "qemu-common.h" #include "qemu.h" +#include "user-internals.h" #include "cpu_loop-common.h" #include "signal-common.h" #include "user-mmap.h" diff --git a/linux-user/i386/signal.c b/linux-user/i386/signal.c index 841cd19651..3b4b55fc0a 100644 --- a/linux-user/i386/signal.c +++ b/linux-user/i386/signal.c @@ -18,6 +18,7 @@ */ #include "qemu/osdep.h" #include "qemu.h" +#include "user-internals.h" #include "signal-common.h" #include "linux-user/trace.h" diff --git a/linux-user/linuxload.c b/linux-user/linuxload.c index 27be7090d8..2ed5fc45ed 100644 --- a/linux-user/linuxload.c +++ b/linux-user/linuxload.c @@ -2,6 +2,7 @@ #include "qemu/osdep.h" #include "qemu.h" +#include "user-internals.h" #include "loader.h" #define NGROUPS 32 diff --git a/linux-user/m68k/cpu_loop.c b/linux-user/m68k/cpu_loop.c index 3a330401bf..ebf32be78f 100644 --- a/linux-user/m68k/cpu_loop.c +++ b/linux-user/m68k/cpu_loop.c @@ -20,6 +20,7 @@ #include "qemu/osdep.h" #include "qemu-common.h" #include "qemu.h" +#include "user-internals.h" #include "cpu_loop-common.h" #include "signal-common.h" diff --git a/linux-user/m68k/signal.c b/linux-user/m68k/signal.c index d06230655e..4f8eb6f727 100644 --- a/linux-user/m68k/signal.c +++ b/linux-user/m68k/signal.c @@ -18,6 +18,7 @@ */ #include "qemu/osdep.h" #include "qemu.h" +#include "user-internals.h" #include "signal-common.h" #include "linux-user/trace.h" diff --git a/linux-user/main.c b/linux-user/main.c index a76aec7336..9edc0b2220 100644 --- a/linux-user/main.c +++ b/linux-user/main.c @@ -30,6 +30,7 @@ #include "qapi/error.h" #include "qemu.h" +#include "user-internals.h" #include "qemu/path.h" #include "qemu/queue.h" #include "qemu/config-file.h" diff --git a/linux-user/microblaze/cpu_loop.c b/linux-user/microblaze/cpu_loop.c index 0d2c8f8dea..52222eb93f 100644 --- a/linux-user/microblaze/cpu_loop.c +++ b/linux-user/microblaze/cpu_loop.c @@ -20,6 +20,7 @@ #include "qemu/osdep.h" #include "qemu-common.h" #include "qemu.h" +#include "user-internals.h" #include "cpu_loop-common.h" #include "signal-common.h" diff --git a/linux-user/microblaze/signal.c b/linux-user/microblaze/signal.c index 4c483bd8c6..b822679d18 100644 --- a/linux-user/microblaze/signal.c +++ b/linux-user/microblaze/signal.c @@ -18,6 +18,7 @@ */ #include "qemu/osdep.h" #include "qemu.h" +#include "user-internals.h" #include "signal-common.h" #include "linux-user/trace.h" diff --git a/linux-user/mips/cpu_loop.c b/linux-user/mips/cpu_loop.c index 7dfaa0cb1e..cb03fb066b 100644 --- a/linux-user/mips/cpu_loop.c +++ b/linux-user/mips/cpu_loop.c @@ -20,6 +20,7 @@ #include "qemu/osdep.h" #include "qemu-common.h" #include "qemu.h" +#include "user-internals.h" #include "cpu_loop-common.h" #include "signal-common.h" #include "elf.h" diff --git a/linux-user/mips/signal.c b/linux-user/mips/signal.c index e6be807a81..d174b3453c 100644 --- a/linux-user/mips/signal.c +++ b/linux-user/mips/signal.c @@ -18,6 +18,7 @@ */ #include "qemu/osdep.h" #include "qemu.h" +#include "user-internals.h" #include "signal-common.h" #include "linux-user/trace.h" diff --git a/linux-user/mmap.c b/linux-user/mmap.c index 4b182444bb..c125031b90 100644 --- a/linux-user/mmap.c +++ b/linux-user/mmap.c @@ -20,6 +20,7 @@ #include "trace.h" #include "exec/log.h" #include "qemu.h" +#include "user-internals.h" #include "user-mmap.h" static pthread_mutex_t mmap_mutex = PTHREAD_MUTEX_INITIALIZER; diff --git a/linux-user/nios2/cpu_loop.c b/linux-user/nios2/cpu_loop.c index 68f95d7ad7..34290fb3b5 100644 --- a/linux-user/nios2/cpu_loop.c +++ b/linux-user/nios2/cpu_loop.c @@ -19,6 +19,7 @@ #include "qemu/osdep.h" #include "qemu.h" +#include "user-internals.h" #include "cpu_loop-common.h" #include "signal-common.h" diff --git a/linux-user/nios2/signal.c b/linux-user/nios2/signal.c index cc3872f11d..a77e8a40f4 100644 --- a/linux-user/nios2/signal.c +++ b/linux-user/nios2/signal.c @@ -18,6 +18,7 @@ */ #include "qemu/osdep.h" #include "qemu.h" +#include "user-internals.h" #include "signal-common.h" #include "linux-user/trace.h" diff --git a/linux-user/openrisc/cpu_loop.c b/linux-user/openrisc/cpu_loop.c index f6c6785988..f6360db47c 100644 --- a/linux-user/openrisc/cpu_loop.c +++ b/linux-user/openrisc/cpu_loop.c @@ -20,6 +20,7 @@ #include "qemu/osdep.h" #include "qemu-common.h" #include "qemu.h" +#include "user-internals.h" #include "cpu_loop-common.h" #include "signal-common.h" diff --git a/linux-user/openrisc/signal.c b/linux-user/openrisc/signal.c index 5c5640a284..ca2532bf50 100644 --- a/linux-user/openrisc/signal.c +++ b/linux-user/openrisc/signal.c @@ -18,6 +18,7 @@ */ #include "qemu/osdep.h" #include "qemu.h" +#include "user-internals.h" #include "signal-common.h" #include "linux-user/trace.h" diff --git a/linux-user/ppc/cpu_loop.c b/linux-user/ppc/cpu_loop.c index ace431238c..840b23736b 100644 --- a/linux-user/ppc/cpu_loop.c +++ b/linux-user/ppc/cpu_loop.c @@ -20,6 +20,7 @@ #include "qemu/osdep.h" #include "qemu-common.h" #include "qemu.h" +#include "user-internals.h" #include "cpu_loop-common.h" #include "signal-common.h" diff --git a/linux-user/ppc/signal.c b/linux-user/ppc/signal.c index edfad28a37..e4d0dfa3bf 100644 --- a/linux-user/ppc/signal.c +++ b/linux-user/ppc/signal.c @@ -18,6 +18,7 @@ */ #include "qemu/osdep.h" #include "qemu.h" +#include "user-internals.h" #include "signal-common.h" #include "linux-user/trace.h" diff --git a/linux-user/qemu.h b/linux-user/qemu.h index a82a46236e..92290a55c0 100644 --- a/linux-user/qemu.h +++ b/linux-user/qemu.h @@ -1,7 +1,6 @@ #ifndef QEMU_H #define QEMU_H -#include "hostdep.h" #include "cpu.h" #include "exec/exec-all.h" #include "exec/cpu_ldst.h" @@ -10,7 +9,6 @@ #include "exec/user/abitypes.h" -#include "exec/user/thunk.h" #include "syscall_defs.h" #include "target_syscall.h" #include "exec/gdbstub.h" @@ -166,93 +164,9 @@ typedef struct TaskState { struct target_sigaltstack sigaltstack_used; } __attribute__((aligned(16))) TaskState; -extern char *exec_path; -void init_task_state(TaskState *ts); -void task_settid(TaskState *); -void stop_all_tasks(void); -extern const char *qemu_uname_release; -extern unsigned long mmap_min_addr; - -typedef struct IOCTLEntry IOCTLEntry; - -typedef abi_long do_ioctl_fn(const IOCTLEntry *ie, uint8_t *buf_temp, - int fd, int cmd, abi_long arg); - -struct IOCTLEntry { - int target_cmd; - unsigned int host_cmd; - const char *name; - int access; - do_ioctl_fn *do_ioctl; - const argtype arg_type[5]; -}; - -extern IOCTLEntry ioctl_entries[]; - -#define IOC_R 0x0001 -#define IOC_W 0x0002 -#define IOC_RW (IOC_R | IOC_W) - -/* - * Returns true if the image uses the FDPIC ABI. If this is the case, - * we have to provide some information (loadmap, pt_dynamic_info) such - * that the program can be relocated adequately. This is also useful - * when handling signals. - */ -int info_is_fdpic(struct image_info *info); - -void target_set_brk(abi_ulong new_brk); -abi_long do_brk(abi_ulong new_brk); -void syscall_init(void); -abi_long do_syscall(void *cpu_env, int num, abi_long arg1, - abi_long arg2, abi_long arg3, abi_long arg4, - abi_long arg5, abi_long arg6, abi_long arg7, - abi_long arg8); -extern __thread CPUState *thread_cpu; -void cpu_loop(CPUArchState *env); -const char *target_strerror(int err); -int get_osversion(void); -void init_qemu_uname_release(void); -void fork_start(void); -void fork_end(int child); - -/** - * probe_guest_base: - * @image_name: the executable being loaded - * @loaddr: the lowest fixed address in the executable - * @hiaddr: the highest fixed address in the executable - * - * Creates the initial guest address space in the host memory space. - * - * If @loaddr == 0, then no address in the executable is fixed, - * i.e. it is fully relocatable. In that case @hiaddr is the size - * of the executable. - * - * This function will not return if a valid value for guest_base - * cannot be chosen. On return, the executable loader can expect - * - * target_mmap(loaddr, hiaddr - loaddr, ...) - * - * to succeed. - */ -void probe_guest_base(const char *image_name, - abi_ulong loaddr, abi_ulong hiaddr); - #include "qemu/log.h" -/* syscall.c */ -int host_to_target_waitstatus(int status); - -#ifdef TARGET_I386 -/* vm86.c */ -void save_v86_state(CPUX86State *env); -void handle_vm86_trap(CPUX86State *env, int trapno); -void handle_vm86_fault(CPUX86State *env); -int do_vm86(CPUX86State *env, long subfunction, abi_ulong v86_addr); -#elif defined(TARGET_SPARC64) -void sparc64_set_context(CPUSPARCState *env); -void sparc64_get_context(CPUSPARCState *env); -#endif +abi_long do_brk(abi_ulong new_brk); /* user access */ @@ -437,80 +351,4 @@ void *lock_user_string(abi_ulong guest_addr); unlock_user(host_ptr, guest_addr, (copy) ? sizeof(*host_ptr) : 0) #include - -static inline int is_error(abi_long ret) -{ - return (abi_ulong)ret >= (abi_ulong)(-4096); -} - -#if TARGET_ABI_BITS == 32 -static inline uint64_t target_offset64(uint32_t word0, uint32_t word1) -{ -#ifdef TARGET_WORDS_BIGENDIAN - return ((uint64_t)word0 << 32) | word1; -#else - return ((uint64_t)word1 << 32) | word0; -#endif -} -#else /* TARGET_ABI_BITS == 32 */ -static inline uint64_t target_offset64(uint64_t word0, uint64_t word1) -{ - return word0; -} -#endif /* TARGET_ABI_BITS != 32 */ - -void print_termios(void *arg); - -/* ARM EABI and MIPS expect 64bit types aligned even on pairs or registers */ -#ifdef TARGET_ARM -static inline int regpairs_aligned(void *cpu_env, int num) -{ - return ((((CPUARMState *)cpu_env)->eabi) == 1) ; -} -#elif defined(TARGET_MIPS) && (TARGET_ABI_BITS == 32) -static inline int regpairs_aligned(void *cpu_env, int num) { return 1; } -#elif defined(TARGET_PPC) && !defined(TARGET_PPC64) -/* - * SysV AVI for PPC32 expects 64bit parameters to be passed on odd/even pairs - * of registers which translates to the same as ARM/MIPS, because we start with - * r3 as arg1 - */ -static inline int regpairs_aligned(void *cpu_env, int num) { return 1; } -#elif defined(TARGET_SH4) -/* SH4 doesn't align register pairs, except for p{read,write}64 */ -static inline int regpairs_aligned(void *cpu_env, int num) -{ - switch (num) { - case TARGET_NR_pread64: - case TARGET_NR_pwrite64: - return 1; - - default: - return 0; - } -} -#elif defined(TARGET_XTENSA) -static inline int regpairs_aligned(void *cpu_env, int num) { return 1; } -#elif defined(TARGET_HEXAGON) -static inline int regpairs_aligned(void *cpu_env, int num) { return 1; } -#else -static inline int regpairs_aligned(void *cpu_env, int num) { return 0; } -#endif - -/** - * preexit_cleanup: housekeeping before the guest exits - * - * env: the CPU state - * code: the exit code - */ -void preexit_cleanup(CPUArchState *env, int code); - -/* - * Include target-specific struct and function definitions; - * they may need access to the target-independent structures - * above, so include them last. - */ -#include "target_cpu.h" -#include "target_structs.h" - #endif /* QEMU_H */ diff --git a/linux-user/riscv/cpu_loop.c b/linux-user/riscv/cpu_loop.c index 47978c4e35..9859a366e4 100644 --- a/linux-user/riscv/cpu_loop.c +++ b/linux-user/riscv/cpu_loop.c @@ -21,6 +21,7 @@ #include "qemu-common.h" #include "qemu/error-report.h" #include "qemu.h" +#include "user-internals.h" #include "cpu_loop-common.h" #include "signal-common.h" #include "elf.h" diff --git a/linux-user/riscv/signal.c b/linux-user/riscv/signal.c index 9405c7fd9a..f7f33bc90a 100644 --- a/linux-user/riscv/signal.c +++ b/linux-user/riscv/signal.c @@ -18,6 +18,7 @@ */ #include "qemu/osdep.h" #include "qemu.h" +#include "user-internals.h" #include "signal-common.h" #include "linux-user/trace.h" diff --git a/linux-user/s390x/cpu_loop.c b/linux-user/s390x/cpu_loop.c index ae70f63053..69b69981f6 100644 --- a/linux-user/s390x/cpu_loop.c +++ b/linux-user/s390x/cpu_loop.c @@ -20,6 +20,7 @@ #include "qemu/osdep.h" #include "qemu-common.h" #include "qemu.h" +#include "user-internals.h" #include "cpu_loop-common.h" #include "signal-common.h" diff --git a/linux-user/s390x/signal.c b/linux-user/s390x/signal.c index bf8a8fbfe9..80f34086d7 100644 --- a/linux-user/s390x/signal.c +++ b/linux-user/s390x/signal.c @@ -18,6 +18,7 @@ */ #include "qemu/osdep.h" #include "qemu.h" +#include "user-internals.h" #include "signal-common.h" #include "linux-user/trace.h" diff --git a/linux-user/semihost.c b/linux-user/semihost.c index f53ab526fb..17f074ac56 100644 --- a/linux-user/semihost.c +++ b/linux-user/semihost.c @@ -13,6 +13,7 @@ #include "qemu/osdep.h" #include "semihosting/console.h" #include "qemu.h" +#include "user-internals.h" #include int qemu_semihosting_console_outs(CPUArchState *env, target_ulong addr) diff --git a/linux-user/sh4/cpu_loop.c b/linux-user/sh4/cpu_loop.c index 06e4a4d007..65b8972e3c 100644 --- a/linux-user/sh4/cpu_loop.c +++ b/linux-user/sh4/cpu_loop.c @@ -20,6 +20,7 @@ #include "qemu/osdep.h" #include "qemu-common.h" #include "qemu.h" +#include "user-internals.h" #include "cpu_loop-common.h" #include "signal-common.h" diff --git a/linux-user/sh4/signal.c b/linux-user/sh4/signal.c index 0451e65806..d70d744bef 100644 --- a/linux-user/sh4/signal.c +++ b/linux-user/sh4/signal.c @@ -18,6 +18,7 @@ */ #include "qemu/osdep.h" #include "qemu.h" +#include "user-internals.h" #include "signal-common.h" #include "linux-user/trace.h" diff --git a/linux-user/signal.c b/linux-user/signal.c index 0fa15f088b..6af66123d0 100644 --- a/linux-user/signal.c +++ b/linux-user/signal.c @@ -22,6 +22,7 @@ #include #include "qemu.h" +#include "user-internals.h" #include "strace.h" #include "loader.h" #include "trace.h" diff --git a/linux-user/sparc/cpu_loop.c b/linux-user/sparc/cpu_loop.c index b2c0611194..ad29b4eb6a 100644 --- a/linux-user/sparc/cpu_loop.c +++ b/linux-user/sparc/cpu_loop.c @@ -20,6 +20,7 @@ #include "qemu/osdep.h" #include "qemu-common.h" #include "qemu.h" +#include "user-internals.h" #include "cpu_loop-common.h" #include "signal-common.h" diff --git a/linux-user/sparc/signal.c b/linux-user/sparc/signal.c index 0cc3db5570..3bc023d281 100644 --- a/linux-user/sparc/signal.c +++ b/linux-user/sparc/signal.c @@ -18,6 +18,7 @@ */ #include "qemu/osdep.h" #include "qemu.h" +#include "user-internals.h" #include "signal-common.h" #include "linux-user/trace.h" diff --git a/linux-user/strace.c b/linux-user/strace.c index ee3429fae8..2cdbf030ba 100644 --- a/linux-user/strace.c +++ b/linux-user/strace.c @@ -15,6 +15,7 @@ #include #include #include "qemu.h" +#include "user-internals.h" #include "strace.h" struct syscallname { diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 9873830b46..e4ffdec0d8 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -127,6 +127,7 @@ #include "uname.h" #include "qemu.h" +#include "user-internals.h" #include "strace.h" #include "signal-common.h" #include "loader.h" diff --git a/linux-user/uaccess.c b/linux-user/uaccess.c index 6a5b029607..425cbf677f 100644 --- a/linux-user/uaccess.c +++ b/linux-user/uaccess.c @@ -3,6 +3,7 @@ #include "qemu/cutils.h" #include "qemu.h" +#include "user-internals.h" void *lock_user(int type, abi_ulong guest_addr, ssize_t len, bool copy) { diff --git a/linux-user/uname.c b/linux-user/uname.c index a09ffe1ea7..1d82608c10 100644 --- a/linux-user/uname.c +++ b/linux-user/uname.c @@ -20,6 +20,7 @@ #include "qemu/osdep.h" #include "qemu.h" +#include "user-internals.h" //#include "qemu-common.h" #include "uname.h" diff --git a/linux-user/user-internals.h b/linux-user/user-internals.h new file mode 100644 index 0000000000..1729a8b62e --- /dev/null +++ b/linux-user/user-internals.h @@ -0,0 +1,184 @@ +/* + * user-internals.h: prototypes etc internal to the linux-user implementation + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see . + */ + +#ifndef LINUX_USER_USER_INTERNALS_H +#define LINUX_USER_USER_INTERNALS_H + +#include "hostdep.h" +#include "exec/user/thunk.h" + +extern char *exec_path; +void init_task_state(TaskState *ts); +void task_settid(TaskState *); +void stop_all_tasks(void); +extern const char *qemu_uname_release; +extern unsigned long mmap_min_addr; + +typedef struct IOCTLEntry IOCTLEntry; + +typedef abi_long do_ioctl_fn(const IOCTLEntry *ie, uint8_t *buf_temp, + int fd, int cmd, abi_long arg); + +struct IOCTLEntry { + int target_cmd; + unsigned int host_cmd; + const char *name; + int access; + do_ioctl_fn *do_ioctl; + const argtype arg_type[5]; +}; + +extern IOCTLEntry ioctl_entries[]; + +#define IOC_R 0x0001 +#define IOC_W 0x0002 +#define IOC_RW (IOC_R | IOC_W) + +/* + * Returns true if the image uses the FDPIC ABI. If this is the case, + * we have to provide some information (loadmap, pt_dynamic_info) such + * that the program can be relocated adequately. This is also useful + * when handling signals. + */ +int info_is_fdpic(struct image_info *info); + +void target_set_brk(abi_ulong new_brk); +void syscall_init(void); +abi_long do_syscall(void *cpu_env, int num, abi_long arg1, + abi_long arg2, abi_long arg3, abi_long arg4, + abi_long arg5, abi_long arg6, abi_long arg7, + abi_long arg8); +extern __thread CPUState *thread_cpu; +void cpu_loop(CPUArchState *env); +const char *target_strerror(int err); +int get_osversion(void); +void init_qemu_uname_release(void); +void fork_start(void); +void fork_end(int child); + +/** + * probe_guest_base: + * @image_name: the executable being loaded + * @loaddr: the lowest fixed address in the executable + * @hiaddr: the highest fixed address in the executable + * + * Creates the initial guest address space in the host memory space. + * + * If @loaddr == 0, then no address in the executable is fixed, + * i.e. it is fully relocatable. In that case @hiaddr is the size + * of the executable. + * + * This function will not return if a valid value for guest_base + * cannot be chosen. On return, the executable loader can expect + * + * target_mmap(loaddr, hiaddr - loaddr, ...) + * + * to succeed. + */ +void probe_guest_base(const char *image_name, + abi_ulong loaddr, abi_ulong hiaddr); + +/* syscall.c */ +int host_to_target_waitstatus(int status); + +#ifdef TARGET_I386 +/* vm86.c */ +void save_v86_state(CPUX86State *env); +void handle_vm86_trap(CPUX86State *env, int trapno); +void handle_vm86_fault(CPUX86State *env); +int do_vm86(CPUX86State *env, long subfunction, abi_ulong v86_addr); +#elif defined(TARGET_SPARC64) +void sparc64_set_context(CPUSPARCState *env); +void sparc64_get_context(CPUSPARCState *env); +#endif + +static inline int is_error(abi_long ret) +{ + return (abi_ulong)ret >= (abi_ulong)(-4096); +} + +#if TARGET_ABI_BITS == 32 +static inline uint64_t target_offset64(uint32_t word0, uint32_t word1) +{ +#ifdef TARGET_WORDS_BIGENDIAN + return ((uint64_t)word0 << 32) | word1; +#else + return ((uint64_t)word1 << 32) | word0; +#endif +} +#else /* TARGET_ABI_BITS == 32 */ +static inline uint64_t target_offset64(uint64_t word0, uint64_t word1) +{ + return word0; +} +#endif /* TARGET_ABI_BITS != 32 */ + +void print_termios(void *arg); + +/* ARM EABI and MIPS expect 64bit types aligned even on pairs or registers */ +#ifdef TARGET_ARM +static inline int regpairs_aligned(void *cpu_env, int num) +{ + return ((((CPUARMState *)cpu_env)->eabi) == 1) ; +} +#elif defined(TARGET_MIPS) && (TARGET_ABI_BITS == 32) +static inline int regpairs_aligned(void *cpu_env, int num) { return 1; } +#elif defined(TARGET_PPC) && !defined(TARGET_PPC64) +/* + * SysV AVI for PPC32 expects 64bit parameters to be passed on odd/even pairs + * of registers which translates to the same as ARM/MIPS, because we start with + * r3 as arg1 + */ +static inline int regpairs_aligned(void *cpu_env, int num) { return 1; } +#elif defined(TARGET_SH4) +/* SH4 doesn't align register pairs, except for p{read,write}64 */ +static inline int regpairs_aligned(void *cpu_env, int num) +{ + switch (num) { + case TARGET_NR_pread64: + case TARGET_NR_pwrite64: + return 1; + + default: + return 0; + } +} +#elif defined(TARGET_XTENSA) +static inline int regpairs_aligned(void *cpu_env, int num) { return 1; } +#elif defined(TARGET_HEXAGON) +static inline int regpairs_aligned(void *cpu_env, int num) { return 1; } +#else +static inline int regpairs_aligned(void *cpu_env, int num) { return 0; } +#endif + +/** + * preexit_cleanup: housekeeping before the guest exits + * + * env: the CPU state + * code: the exit code + */ +void preexit_cleanup(CPUArchState *env, int code); + +/* + * Include target-specific struct and function definitions; + * they may need access to the target-independent structures + * above, so include them last. + */ +#include "target_cpu.h" +#include "target_structs.h" + +#endif diff --git a/linux-user/vm86.c b/linux-user/vm86.c index 4412522c4c..c2facf3fc2 100644 --- a/linux-user/vm86.c +++ b/linux-user/vm86.c @@ -19,6 +19,7 @@ #include "qemu/osdep.h" #include "qemu.h" +#include "user-internals.h" //#define DEBUG_VM86 diff --git a/linux-user/xtensa/cpu_loop.c b/linux-user/xtensa/cpu_loop.c index bb5335e2b6..622afbcd34 100644 --- a/linux-user/xtensa/cpu_loop.c +++ b/linux-user/xtensa/cpu_loop.c @@ -19,6 +19,7 @@ #include "qemu/osdep.h" #include "qemu.h" +#include "user-internals.h" #include "cpu_loop-common.h" #include "signal-common.h" diff --git a/linux-user/xtensa/signal.c b/linux-user/xtensa/signal.c index 72771e1294..7a3bfb92ca 100644 --- a/linux-user/xtensa/signal.c +++ b/linux-user/xtensa/signal.c @@ -18,6 +18,7 @@ */ #include "qemu/osdep.h" #include "qemu.h" +#include "user-internals.h" #include "signal-common.h" #include "linux-user/trace.h" From 85b4fa0cd189311dc1c69714e669b5a12b0552f6 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Wed, 8 Sep 2021 16:44:04 +0100 Subject: [PATCH 08/10] linux-user: Don't include gdbstub.h in qemu.h MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently the linux-user qemu.h pulls in gdbstub.h. There's no real reason why it should do this; include it directly from the C files which require it, and drop the include line in qemu.h. (Note that several of the C files previously relying on this indirect include were going out of their way to only include gdbstub.h conditionally on not CONFIG_USER_ONLY!) Signed-off-by: Peter Maydell Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Richard Henderson Message-Id: <20210908154405.15417-9-peter.maydell@linaro.org> Signed-off-by: Laurent Vivier --- gdbstub.c | 2 +- linux-user/exit.c | 1 + linux-user/main.c | 1 + linux-user/qemu.h | 1 - linux-user/signal.c | 2 ++ semihosting/arm-compat-semi.c | 2 +- target/m68k/m68k-semi.c | 2 +- target/nios2/nios2-semi.c | 2 +- 8 files changed, 8 insertions(+), 5 deletions(-) diff --git a/gdbstub.c b/gdbstub.c index 5d8e6ae3cd..36b85aa50e 100644 --- a/gdbstub.c +++ b/gdbstub.c @@ -31,13 +31,13 @@ #include "qemu/cutils.h" #include "qemu/module.h" #include "trace/trace-root.h" +#include "exec/gdbstub.h" #ifdef CONFIG_USER_ONLY #include "qemu.h" #else #include "monitor/monitor.h" #include "chardev/char.h" #include "chardev/char-fe.h" -#include "exec/gdbstub.h" #include "hw/cpu/cluster.h" #include "hw/boards.h" #endif diff --git a/linux-user/exit.c b/linux-user/exit.c index 68a3a6f9df..fa6ef0b9b4 100644 --- a/linux-user/exit.c +++ b/linux-user/exit.c @@ -17,6 +17,7 @@ * along with this program; if not, see . */ #include "qemu/osdep.h" +#include "exec/gdbstub.h" #include "qemu.h" #include "user-internals.h" #ifdef CONFIG_GPROF diff --git a/linux-user/main.c b/linux-user/main.c index 9edc0b2220..5ce17e423d 100644 --- a/linux-user/main.c +++ b/linux-user/main.c @@ -40,6 +40,7 @@ #include "qemu/module.h" #include "qemu/plugin.h" #include "exec/exec-all.h" +#include "exec/gdbstub.h" #include "tcg/tcg.h" #include "qemu/timer.h" #include "qemu/envlist.h" diff --git a/linux-user/qemu.h b/linux-user/qemu.h index 92290a55c0..fda90fc28d 100644 --- a/linux-user/qemu.h +++ b/linux-user/qemu.h @@ -11,7 +11,6 @@ #include "syscall_defs.h" #include "target_syscall.h" -#include "exec/gdbstub.h" /* * This is the size of the host kernel's sigset_t, needed where we make diff --git a/linux-user/signal.c b/linux-user/signal.c index 6af66123d0..f8346f5ec5 100644 --- a/linux-user/signal.c +++ b/linux-user/signal.c @@ -18,6 +18,8 @@ */ #include "qemu/osdep.h" #include "qemu/bitops.h" +#include "exec/gdbstub.h" + #include #include diff --git a/semihosting/arm-compat-semi.c b/semihosting/arm-compat-semi.c index 1c29146dcf..01badea99c 100644 --- a/semihosting/arm-compat-semi.c +++ b/semihosting/arm-compat-semi.c @@ -37,12 +37,12 @@ #include "semihosting/console.h" #include "semihosting/common-semi.h" #include "qemu/timer.h" +#include "exec/gdbstub.h" #ifdef CONFIG_USER_ONLY #include "qemu.h" #define COMMON_SEMI_HEAP_SIZE (128 * 1024 * 1024) #else -#include "exec/gdbstub.h" #include "qemu/cutils.h" #ifdef TARGET_ARM #include "hw/arm/boot.h" diff --git a/target/m68k/m68k-semi.c b/target/m68k/m68k-semi.c index d919245e4f..44ec7e4612 100644 --- a/target/m68k/m68k-semi.c +++ b/target/m68k/m68k-semi.c @@ -20,11 +20,11 @@ #include "qemu/osdep.h" #include "cpu.h" +#include "exec/gdbstub.h" #if defined(CONFIG_USER_ONLY) #include "qemu.h" #define SEMIHOSTING_HEAP_SIZE (128 * 1024 * 1024) #else -#include "exec/gdbstub.h" #include "exec/softmmu-semi.h" #include "hw/boards.h" #endif diff --git a/target/nios2/nios2-semi.c b/target/nios2/nios2-semi.c index e508b2fafc..fe5598bae4 100644 --- a/target/nios2/nios2-semi.c +++ b/target/nios2/nios2-semi.c @@ -24,11 +24,11 @@ #include "qemu/osdep.h" #include "cpu.h" +#include "exec/gdbstub.h" #if defined(CONFIG_USER_ONLY) #include "qemu.h" #else #include "qemu-common.h" -#include "exec/gdbstub.h" #include "exec/softmmu-semi.h" #endif #include "qemu/log.h" From d0a7920eb4fc44dd4485167edf7db7fac1de6977 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Wed, 8 Sep 2021 16:44:05 +0100 Subject: [PATCH 09/10] linux-user: Drop unneeded includes from qemu.h MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Trim down the #includes in qemu.h where we can, either by dropping unneeded headers or by moving them to user-internals.h. This includes deleting a couple of #includes that appear at weird points midway through the header file. Signed-off-by: Peter Maydell Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Richard Henderson Message-Id: <20210908154405.15417-10-peter.maydell@linaro.org> Signed-off-by: Laurent Vivier --- linux-user/qemu.h | 4 ---- linux-user/user-internals.h | 2 ++ thunk.c | 1 + 3 files changed, 3 insertions(+), 4 deletions(-) diff --git a/linux-user/qemu.h b/linux-user/qemu.h index fda90fc28d..5c713fa8ab 100644 --- a/linux-user/qemu.h +++ b/linux-user/qemu.h @@ -2,7 +2,6 @@ #define QEMU_H #include "cpu.h" -#include "exec/exec-all.h" #include "exec/cpu_ldst.h" #undef DEBUG_REMAP @@ -163,8 +162,6 @@ typedef struct TaskState { struct target_sigaltstack sigaltstack_used; } __attribute__((aligned(16))) TaskState; -#include "qemu/log.h" - abi_long do_brk(abi_ulong new_brk); /* user access */ @@ -349,5 +346,4 @@ void *lock_user_string(abi_ulong guest_addr); #define unlock_user_struct(host_ptr, guest_addr, copy) \ unlock_user(host_ptr, guest_addr, (copy) ? sizeof(*host_ptr) : 0) -#include #endif /* QEMU_H */ diff --git a/linux-user/user-internals.h b/linux-user/user-internals.h index 1729a8b62e..661612a088 100644 --- a/linux-user/user-internals.h +++ b/linux-user/user-internals.h @@ -20,6 +20,8 @@ #include "hostdep.h" #include "exec/user/thunk.h" +#include "exec/exec-all.h" +#include "qemu/log.h" extern char *exec_path; void init_task_state(TaskState *ts); diff --git a/thunk.c b/thunk.c index fc5be1a502..dac4bf11c6 100644 --- a/thunk.c +++ b/thunk.c @@ -17,6 +17,7 @@ * License along with this library; if not, see . */ #include "qemu/osdep.h" +#include "qemu/log.h" #include "qemu.h" #include "exec/user/thunk.h" From 74e43b04b0260da09d14bc56a5d629d4753b8b27 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 9 Aug 2021 16:54:24 +0100 Subject: [PATCH 10/10] linux-user: Check lock_user result for ip_mreq_source sockopts MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In do_setsockopt(), the code path for the options which take a struct ip_mreq_source (IP_BLOCK_SOURCE, IP_UNBLOCK_SOURCE, IP_ADD_SOURCE_MEMBERSHIP and IP_DROP_SOURCE_MEMBERSHIP) fails to check the return value from lock_user(). Handle this in the usual way by returning -TARGET_EFAULT. (In practice this was probably harmless because we'd pass a NULL pointer to setsockopt() and the kernel would then return EFAULT.) Fixes: Coverity CID 1459987 Signed-off-by: Peter Maydell Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Laurent Vivier Message-Id: <20210809155424.30968-1-peter.maydell@linaro.org> Signed-off-by: Laurent Vivier --- linux-user/syscall.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/linux-user/syscall.c b/linux-user/syscall.c index e4ffdec0d8..544f5b662f 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -2127,6 +2127,9 @@ static abi_long do_setsockopt(int sockfd, int level, int optname, return -TARGET_EINVAL; ip_mreq_source = lock_user(VERIFY_READ, optval_addr, optlen, 1); + if (!ip_mreq_source) { + return -TARGET_EFAULT; + } ret = get_errno(setsockopt(sockfd, level, optname, ip_mreq_source, optlen)); unlock_user (ip_mreq_source, optval_addr, 0); break;