From: Nicola Vetrini <nicola.vetr...@bugseng.com>
Rule 13.2 states: "The value of an expression and its persistent
side effects shall be the same under all permitted evaluation orders".
The full expansion of macro "commit_far_branch" contains an assignment to
variable "rc", which is also assigned to the result of the GNU statement
expression which "commit_far_branch" expands to.
To avoid any dependence on the order of evaluation, the latter assignment
is moved inside the macro.
Signed-off-by: Nicola Vetrini <nicola.vetr...@bugseng.com>
Signed-off-by: Victor Lira <victorm.l...@amd.com>
---
Cc: Andrew Cooper <andrew.coop...@citrix.com>
Cc: Anthony PERARD <anthony.per...@vates.tech>
Cc: Michal Orzel <michal.or...@amd.com>
Cc: Jan Beulich <jbeul...@suse.com>
Cc: Julien Grall <jul...@xen.org>
Cc: Roger Pau Monné <roger....@citrix.com>
Cc: Stefano Stabellini <sstabell...@kernel.org>
Cc: Nicola Vetrini <nicola.vetr...@bugseng.com>
Cc: Federico Serafini <federico.seraf...@bugseng.com>
Cc: Bertrand Marquis <bertrand.marq...@arm.com>
---
xen/arch/x86/x86_emulate/x86_emulate.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/xen/arch/x86/x86_emulate/x86_emulate.c
b/xen/arch/x86/x86_emulate/x86_emulate.c
index 8e14ebb35b..7108fe7b30 100644
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -337,7 +337,7 @@ do {
\
validate_far_branch(cs, newip); \
_regs.r(ip) = (newip); \
singlestep = _regs.eflags & X86_EFLAGS_TF; \
- ops->write_segment(x86_seg_cs, cs, ctxt); \
+ rc = ops->write_segment(x86_seg_cs, cs, ctxt); \
})
int x86emul_get_fpu(
@@ -2382,7 +2382,7 @@ x86_emulate(
(rc = read_ulong(x86_seg_ss, sp_post_inc(op_bytes + src.val),
&src.val, op_bytes, ctxt, ops)) ||
(rc = load_seg(x86_seg_cs, src.val, 1, &cs, ctxt, ops)) ||
- (rc = commit_far_branch(&cs, dst.val)) )
+ commit_far_branch(&cs, dst.val) )
goto done;
break;
@@ -2438,7 +2438,7 @@ x86_emulate(
_regs.eflags &= mask;
_regs.eflags |= (eflags & ~mask) | X86_EFLAGS_MBS;
if ( (rc = load_seg(x86_seg_cs, sel, 1, &cs, ctxt, ops)) ||
- (rc = commit_far_branch(&cs, (uint32_t)eip)) )
+ commit_far_branch(&cs, (uint32_t)eip) )
goto done;
break;
}
@@ -2557,7 +2557,7 @@ x86_emulate(
ASSERT(!mode_64bit());
far_jmp:
if ( (rc = load_seg(x86_seg_cs, imm2, 0, &cs, ctxt, ops)) ||
- (rc = commit_far_branch(&cs, imm1)) )
+ commit_far_branch(&cs, imm1) )
goto done;
break;
--
2.47.0
