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target/i386: Do not re-compute new pc with CF_PCREL #50

Merged
dfaggioli merged 2 commits from v8.2.0-factory-fix into factory 2024-02-06 01:38:57 +01:00
Conversation 0 Commits 2 Files Changed 1 +4 -6

2 Commits

Author SHA1 Message Date
guoguangyao
05615e903f target/i386: fix incorrect EIP in PC-relative translation blocks 
The PCREL patches introduced a bug when updating EIP in the !CF_PCREL case.
Using s->pc in func gen_update_eip_next() solves the problem.

Cc: qemu-stable@nongnu.org
Fixes: b5e0d5d22f ("target/i386: Fix 32-bit wrapping of pc/eip computation")
Signed-off-by: guoguangyao <guoguangyao18@mails.ucas.ac.cn>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20240115020804.30272-1-guoguangyao18@mails.ucas.ac.cn>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 2926eab896)
Signed-off-by: Dario Faggioli <dfaggioli@suse.com>
 2024-02-05 23:32:47 +01:00
Richard Henderson
a8bde2db10 target/i386: Do not re-compute new pc with CF_PCREL 
With PCREL, we have a page-relative view of EIP, and an
approximation of PC = EIP+CSBASE that is good enough to
detect page crossings.  If we try to recompute PC after
masking EIP, we will mess up that approximation and write
a corrupt value to EIP.

We already handled masking properly for PCREL, so the
fix in b5e0d5d2 was only needed for the !PCREL path.

Cc: qemu-stable@nongnu.org
Fixes: b5e0d5d22f ("target/i386: Fix 32-bit wrapping of pc/eip computation")
Reported-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20240101230617.129349-1-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit a58506b748)
Signed-off-by: Dario Faggioli <dfaggioli@suse.com>
 2024-02-05 23:00:30 +01:00