From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48191) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1etCVb-0005EH-FG for qemu-devel@nongnu.org; Tue, 06 Mar 2018 08:20:00 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1etCVX-0006Nx-Fa for qemu-devel@nongnu.org; Tue, 06 Mar 2018 08:19:59 -0500 Received: from mail-wr0-x243.google.com ([2a00:1450:400c:c0c::243]:42918) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1etCVX-0006NX-8Y for qemu-devel@nongnu.org; Tue, 06 Mar 2018 08:19:55 -0500 Received: by mail-wr0-x243.google.com with SMTP id k9so20878356wre.9 for ; Tue, 06 Mar 2018 05:19:55 -0800 (PST) Received: from 640k.lan (94-36-191-219.adsl-ull.clienti.tiscali.it. [94.36.191.219]) by smtp.gmail.com with ESMTPSA id l38sm25652538wrc.96.2018.03.06.05.19.52 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 06 Mar 2018 05:19:53 -0800 (PST) Sender: Paolo Bonzini From: Paolo Bonzini Date: Tue, 6 Mar 2018 14:19:13 +0100 Message-Id: <1520342370-123606-18-git-send-email-pbonzini@redhat.com> In-Reply-To: <1520342370-123606-1-git-send-email-pbonzini@redhat.com> References: <1520342370-123606-1-git-send-email-pbonzini@redhat.com> Subject: [Qemu-devel] [PULL 17/34] address_space_write: address_space_to_flatview needs RCU lock List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org 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. Reviewed-by: Alexey Kardashevskiy Signed-off-by: Paolo Bonzini --- exec.c | 37 ++++++++++++++++++++++--------------- 1 file changed, 22 insertions(+), 15 deletions(-) diff --git a/exec.c b/exec.c index 4d8addb..ec91162 100644 --- a/exec.c +++ b/exec.c @@ -3078,6 +3078,7 @@ static MemTxResult flatview_write_continue(FlatView *fv, hwaddr addr, return result; } +/* Called from RCU critical section. */ static MemTxResult flatview_write(FlatView *fv, hwaddr addr, MemTxAttrs attrs, const uint8_t *buf, int len) { @@ -3086,25 +3087,14 @@ static MemTxResult flatview_write(FlatView *fv, hwaddr addr, MemTxAttrs attrs, MemoryRegion *mr; MemTxResult result = MEMTX_OK; - if (len > 0) { - rcu_read_lock(); - l = len; - mr = flatview_translate(fv, addr, &addr1, &l, true); - result = flatview_write_continue(fv, addr, attrs, buf, len, - addr1, l, mr); - rcu_read_unlock(); - } + l = len; + mr = flatview_translate(fv, addr, &addr1, &l, true); + result = flatview_write_continue(fv, addr, attrs, buf, len, + addr1, l, mr); return result; } -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, @@ -3213,6 +3203,23 @@ MemTxResult address_space_rw(AddressSpace *as, hwaddr addr, addr, attrs, buf, len, is_write); } +MemTxResult address_space_write(AddressSpace *as, hwaddr addr, + MemTxAttrs attrs, + const 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_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) { -- 1.8.3.1