mirror of
https://github.com/archlinuxarm/PKGBUILDs.git
synced 2024-11-08 22:45:43 +00:00
44 lines
1.5 KiB
Diff
44 lines
1.5 KiB
Diff
|
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: b5e0d5d22fbf ("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>
|
||
|
---
|
||
|
target/i386/tcg/translate.c | 6 ++----
|
||
|
1 file changed, 2 insertions(+), 4 deletions(-)
|
||
|
|
||
|
diff --git a/target/i386/tcg/translate.c b/target/i386/tcg/translate.c
|
||
|
index 037bc47e7c..e68375b19d 100644
|
||
|
--- a/target/i386/tcg/translate.c
|
||
|
+++ b/target/i386/tcg/translate.c
|
||
|
@@ -2845,10 +2845,6 @@ static void gen_jmp_rel(DisasContext *s, MemOp ot, int diff, int tb_num)
|
||
|
}
|
||
|
}
|
||
|
new_eip &= mask;
|
||
|
- new_pc = new_eip + s->cs_base;
|
||
|
- if (!CODE64(s)) {
|
||
|
- new_pc = (uint32_t)new_pc;
|
||
|
- }
|
||
|
|
||
|
gen_update_cc_op(s);
|
||
|
set_cc_op(s, CC_OP_DYNAMIC);
|
||
|
@@ -2864,6 +2860,8 @@ static void gen_jmp_rel(DisasContext *s, MemOp ot, int diff, int tb_num)
|
||
|
tcg_gen_andi_tl(cpu_eip, cpu_eip, mask);
|
||
|
use_goto_tb = false;
|
||
|
}
|
||
|
+ } else if (!CODE64(s)) {
|
||
|
+ new_pc = (uint32_t)(new_eip + s->cs_base);
|
||
|
}
|
||
|
|
||
|
if (use_goto_tb && translator_use_goto_tb(&s->base, new_pc)) {
|
||
|
--
|
||
|
2.34.1
|