From b2a44fcad74f1cc7a6786d38eba7db12ab2352ba Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Mon, 5 Mar 2018 00:19:49 +0100 Subject: 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 Signed-off-by: Paolo Bonzini --- exec.c | 38 +++++++++++++++++++++++++------------- 1 file changed, 25 insertions(+), 13 deletions(-) (limited to 'exec.c') diff --git a/exec.c b/exec.c index ec91162..e4552ee 100644 --- a/exec.c +++ b/exec.c @@ -2616,6 +2616,8 @@ static const MemoryRegionOps watch_mem_ops = { }, }; +static MemTxResult flatview_read(FlatView *fv, hwaddr addr, + MemTxAttrs attrs, uint8_t *buf, int len); static MemTxResult flatview_write(FlatView *fv, hwaddr addr, MemTxAttrs attrs, const uint8_t *buf, int len); static bool flatview_access_valid(FlatView *fv, hwaddr addr, int len, @@ -3165,24 +3167,18 @@ MemTxResult flatview_read_continue(FlatView *fv, hwaddr addr, return result; } -MemTxResult flatview_read_full(FlatView *fv, hwaddr addr, - MemTxAttrs attrs, uint8_t *buf, int len) +/* Called from RCU critical section. */ +static MemTxResult flatview_read(FlatView *fv, hwaddr addr, + MemTxAttrs attrs, uint8_t *buf, int len) { hwaddr l; hwaddr addr1; MemoryRegion *mr; - MemTxResult result = MEMTX_OK; - - if (len > 0) { - rcu_read_lock(); - l = len; - mr = flatview_translate(fv, addr, &addr1, &l, false); - result = flatview_read_continue(fv, addr, attrs, buf, len, - addr1, l, mr); - rcu_read_unlock(); - } - return result; + l = len; + mr = flatview_translate(fv, addr, &addr1, &l, false); + return flatview_read_continue(fv, addr, attrs, buf, len, + addr1, l, mr); } static MemTxResult flatview_rw(FlatView *fv, hwaddr addr, MemTxAttrs attrs, @@ -3203,6 +3199,22 @@ MemTxResult address_space_rw(AddressSpace *as, hwaddr addr, addr, attrs, buf, len, is_write); } +MemTxResult address_space_read_full(AddressSpace *as, hwaddr addr, + MemTxAttrs attrs, uint8_t *buf, int len) +{ + MemTxResult result = MEMTX_OK; + FlatView *fv; + + if (len > 0) { + rcu_read_lock(); + fv = address_space_to_flatview(as); + result = flatview_read(fv, addr, attrs, buf, len); + rcu_read_unlock(); + } + + return result; +} + MemTxResult address_space_write(AddressSpace *as, hwaddr addr, MemTxAttrs attrs, const uint8_t *buf, int len) -- cgit v1.1