Using mprotect() to change PROT_* does not change the MAP_ANON previously set with mmap(). Our linux-user version of MTE only works with MAP_ANON pages, so losing PAGE_ANON caused MTE to stop working. Reported-by: Stephen Long <steplong@quicinc.com> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Tested-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
44 lines
830 B
C
44 lines
830 B
C
#include "mte.h"
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void pass(int sig, siginfo_t *info, void *uc)
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{
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assert(info->si_code == SEGV_MTESERR);
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exit(0);
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}
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int main(void)
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{
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enable_mte(PR_MTE_TCF_SYNC);
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void *brk = sbrk(16);
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if (brk == (void *)-1) {
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perror("sbrk");
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return 2;
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}
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if (mprotect(brk, 16, PROT_READ | PROT_WRITE | PROT_MTE)) {
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perror("mprotect");
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return 2;
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}
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int *p1, *p2;
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long excl = 1;
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asm("irg %0,%1,%2" : "=r"(p1) : "r"(brk), "r"(excl));
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asm("gmi %0,%1,%0" : "+r"(excl) : "r"(p1));
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asm("irg %0,%1,%2" : "=r"(p2) : "r"(brk), "r"(excl));
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asm("stg %0,[%0]" : : "r"(p1));
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*p1 = 0;
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struct sigaction sa;
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memset(&sa, 0, sizeof(sa));
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sa.sa_sigaction = pass;
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sa.sa_flags = SA_SIGINFO;
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sigaction(SIGSEGV, &sa, NULL);
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*p2 = 0;
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abort();
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}
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