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X-Received-From: 2a00:1450:400c:c0c::242 Subject: [Qemu-devel] [PATCH 3/7] address_space_write: address_space_to_flatview needs RCU lock X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Alexey Kardashevskiy , qemu-stable@nongnu.org, David Gibson Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) X-ZohoMail: RDKM_2 RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" address_space_write 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_write to address_space_write. Cc: qemu-stable@nongnu.org Signed-off-by: Paolo Bonzini Reviewed-by: Alexey Kardashevskiy --- exec.c | 37 ++++++++++++++++++++++--------------- 1 file changed, 22 insertions(+), 15 deletions(-) diff --git a/exec.c b/exec.c index e8d7b335b6..0b74b58d45 100644 --- a/exec.c +++ b/exec.c @@ -3074,6 +3074,7 @@ static MemTxResult flatview_write_continue(FlatView *= fv, hwaddr addr, return result; } =20 +/* Called from RCU critical section. */ static MemTxResult flatview_write(FlatView *fv, hwaddr addr, MemTxAttrs at= trs, const uint8_t *buf, int len) { @@ -3082,25 +3083,14 @@ static MemTxResult flatview_write(FlatView *fv, hwa= ddr addr, MemTxAttrs attrs, MemoryRegion *mr; MemTxResult result =3D MEMTX_OK; =20 - if (len > 0) { - rcu_read_lock(); - l =3D len; - mr =3D flatview_translate(fv, addr, &addr1, &l, true); - result =3D flatview_write_continue(fv, addr, attrs, buf, len, - addr1, l, mr); - rcu_read_unlock(); - } + l =3D len; + mr =3D flatview_translate(fv, addr, &addr1, &l, true); + result =3D flatview_write_continue(fv, addr, attrs, buf, len, + addr1, l, mr); =20 return result; } =20 -MemTxResult address_space_write(AddressSpace *as, hwaddr addr, - MemTxAttrs attrs, - const uint8_t *buf, int len) -{ - return flatview_write(address_space_to_flatview(as), addr, attrs, buf,= len); -} - /* Called within RCU critical section. */ MemTxResult flatview_read_continue(FlatView *fv, hwaddr addr, MemTxAttrs attrs, uint8_t *buf, @@ -3209,6 +3199,23 @@ MemTxResult address_space_rw(AddressSpace *as, hwadd= r addr, addr, attrs, buf, len, is_write); } =20 +MemTxResult address_space_write(AddressSpace *as, hwaddr addr, + MemTxAttrs attrs, + const uint8_t *buf, int len) +{ + MemTxResult result =3D MEMTX_OK; + FlatView *fv; + + if (len > 0) { + rcu_read_lock(); + fv =3D address_space_to_flatview(as); + result =3D flatview_write(fv, addr, attrs, buf, len); + rcu_read_unlock(); + } + + return result; +} + void cpu_physical_memory_rw(hwaddr addr, uint8_t *buf, int len, int is_write) { --=20 2.14.3