address_space_read: address_space_to_flatview needs RCU lock
address_space_read is calling address_space_to_flatview but it can
be called outside the RCU lock. To fix it, push the rcu_read_lock/unlock
pair up from flatview_read_full to address_space_read's constant size
fast path and address_space_read_full.
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit b2a44fcad7
)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
stable-2.11
parent
df04d1f16a
commit
f77c231202
38
exec.c
38
exec.c
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@ -2575,6 +2575,8 @@ static const MemoryRegionOps watch_mem_ops = {
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},
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};
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static MemTxResult flatview_read(FlatView *fv, hwaddr addr,
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MemTxAttrs attrs, uint8_t *buf, int len);
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static MemTxResult flatview_write(FlatView *fv, hwaddr addr, MemTxAttrs attrs,
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const uint8_t *buf, int len);
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static bool flatview_access_valid(FlatView *fv, hwaddr addr, int len,
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@ -3092,24 +3094,18 @@ MemTxResult flatview_read_continue(FlatView *fv, hwaddr addr,
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return result;
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}
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MemTxResult flatview_read_full(FlatView *fv, hwaddr addr,
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MemTxAttrs attrs, uint8_t *buf, int len)
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/* Called from RCU critical section. */
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static MemTxResult flatview_read(FlatView *fv, hwaddr addr,
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MemTxAttrs attrs, uint8_t *buf, int len)
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{
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hwaddr l;
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hwaddr addr1;
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MemoryRegion *mr;
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MemTxResult result = MEMTX_OK;
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if (len > 0) {
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rcu_read_lock();
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l = len;
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mr = flatview_translate(fv, addr, &addr1, &l, false);
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result = flatview_read_continue(fv, addr, attrs, buf, len,
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addr1, l, mr);
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rcu_read_unlock();
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}
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return result;
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l = len;
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mr = flatview_translate(fv, addr, &addr1, &l, false);
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return flatview_read_continue(fv, addr, attrs, buf, len,
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addr1, l, mr);
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}
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static MemTxResult flatview_rw(FlatView *fv, hwaddr addr, MemTxAttrs attrs,
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@ -3130,6 +3126,22 @@ MemTxResult address_space_rw(AddressSpace *as, hwaddr addr,
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addr, attrs, buf, len, is_write);
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}
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MemTxResult address_space_read_full(AddressSpace *as, hwaddr addr,
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MemTxAttrs attrs, uint8_t *buf, int len)
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{
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MemTxResult result = MEMTX_OK;
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FlatView *fv;
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if (len > 0) {
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rcu_read_lock();
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fv = address_space_to_flatview(as);
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result = flatview_read(fv, addr, attrs, buf, len);
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rcu_read_unlock();
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}
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return result;
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}
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MemTxResult address_space_write(AddressSpace *as, hwaddr addr,
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MemTxAttrs attrs,
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const uint8_t *buf, int len)
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@ -1907,13 +1907,12 @@ void address_space_unmap(AddressSpace *as, void *buffer, hwaddr len,
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/* Internal functions, part of the implementation of address_space_read. */
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MemTxResult address_space_read_full(AddressSpace *as, hwaddr addr,
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MemTxAttrs attrs, uint8_t *buf, int len);
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MemTxResult flatview_read_continue(FlatView *fv, hwaddr addr,
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MemTxAttrs attrs, uint8_t *buf,
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int len, hwaddr addr1, hwaddr l,
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MemoryRegion *mr);
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MemTxResult flatview_read_full(FlatView *fv, hwaddr addr,
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MemTxAttrs attrs, uint8_t *buf, int len);
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void *qemu_map_ram_ptr(RAMBlock *ram_block, ram_addr_t addr);
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static inline bool memory_access_is_direct(MemoryRegion *mr, bool is_write)
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@ -1932,7 +1931,7 @@ static inline bool memory_access_is_direct(MemoryRegion *mr, bool is_write)
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*
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* Return a MemTxResult indicating whether the operation succeeded
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* or failed (eg unassigned memory, device rejected the transaction,
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* IOMMU fault).
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* IOMMU fault). Called within RCU critical section.
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*
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* @as: #AddressSpace to be accessed
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* @addr: address within that address space
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@ -1940,17 +1939,20 @@ static inline bool memory_access_is_direct(MemoryRegion *mr, bool is_write)
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* @buf: buffer with the data transferred
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*/
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static inline __attribute__((__always_inline__))
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MemTxResult flatview_read(FlatView *fv, hwaddr addr, MemTxAttrs attrs,
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uint8_t *buf, int len)
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MemTxResult address_space_read(AddressSpace *as, hwaddr addr,
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MemTxAttrs attrs, uint8_t *buf,
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int len)
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{
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MemTxResult result = MEMTX_OK;
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hwaddr l, addr1;
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void *ptr;
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MemoryRegion *mr;
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FlatView *fv;
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if (__builtin_constant_p(len)) {
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if (len) {
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rcu_read_lock();
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fv = address_space_to_flatview(as);
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l = len;
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mr = flatview_translate(fv, addr, &addr1, &l, false);
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if (len == l && memory_access_is_direct(mr, false)) {
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@ -1963,18 +1965,11 @@ MemTxResult flatview_read(FlatView *fv, hwaddr addr, MemTxAttrs attrs,
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rcu_read_unlock();
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}
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} else {
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result = flatview_read_full(fv, addr, attrs, buf, len);
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result = address_space_read_full(as, addr, attrs, buf, len);
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}
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return result;
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}
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static inline MemTxResult address_space_read(AddressSpace *as, hwaddr addr,
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MemTxAttrs attrs, uint8_t *buf,
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int len)
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{
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return flatview_read(address_space_to_flatview(as), addr, attrs, buf, len);
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}
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/**
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* address_space_read_cached: read from a cached RAM region
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*
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