* [Qemu-devel] [PATCH] Clear RF on SYSCALL instruction
@ 2018-10-19 12:24 Roman Kapl
2018-10-19 12:27 ` Paolo Bonzini
0 siblings, 1 reply; 2+ messages in thread
From: Roman Kapl @ 2018-10-19 12:24 UTC (permalink / raw)
Cc: Rudolf Marek, Roman Kapl, Paolo Bonzini, Richard Henderson,
Eduardo Habkost, qemu-devel
From: Rudolf Marek <rudolf.marek@sysgo.com>
Fix the SYSCALL instruction in 64-bit (long mode). The RF flag
should be cleared in R11 as well as in the RFLAGS. Intel
and AMD CPUs behave same. AMD has this documented in the
APM vol 3.
Signed-off-by: Roman Kapl <rka@sysgo.com>
Signed-off-by: Rudolf Marek <rudolf.marek@sysgo.com>
---
target/i386/seg_helper.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/target/i386/seg_helper.c b/target/i386/seg_helper.c
index 33714bc6e1..63e265cb38 100644
--- a/target/i386/seg_helper.c
+++ b/target/i386/seg_helper.c
@@ -991,11 +991,11 @@ void helper_syscall(CPUX86State *env, int next_eip_addend)
int code64;
env->regs[R_ECX] = env->eip + next_eip_addend;
- env->regs[11] = cpu_compute_eflags(env);
+ env->regs[11] = cpu_compute_eflags(env) & ~RF_MASK;
code64 = env->hflags & HF_CS64_MASK;
- env->eflags &= ~env->fmask;
+ env->eflags &= ~(env->fmask | RF_MASK);
cpu_load_eflags(env, env->eflags, 0);
cpu_x86_load_seg_cache(env, R_CS, selector & 0xfffc,
0, 0xffffffff,
--
2.11.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [Qemu-devel] [PATCH] Clear RF on SYSCALL instruction
2018-10-19 12:24 [Qemu-devel] [PATCH] Clear RF on SYSCALL instruction Roman Kapl
@ 2018-10-19 12:27 ` Paolo Bonzini
0 siblings, 0 replies; 2+ messages in thread
From: Paolo Bonzini @ 2018-10-19 12:27 UTC (permalink / raw)
To: Roman Kapl; +Cc: Rudolf Marek, Richard Henderson, Eduardo Habkost, qemu-devel
On 19/10/2018 14:24, Roman Kapl wrote:
> From: Rudolf Marek <rudolf.marek@sysgo.com>
>
> Fix the SYSCALL instruction in 64-bit (long mode). The RF flag
> should be cleared in R11 as well as in the RFLAGS. Intel
> and AMD CPUs behave same. AMD has this documented in the
> APM vol 3.
>
> Signed-off-by: Roman Kapl <rka@sysgo.com>
> Signed-off-by: Rudolf Marek <rudolf.marek@sysgo.com>
> ---
> target/i386/seg_helper.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/target/i386/seg_helper.c b/target/i386/seg_helper.c
> index 33714bc6e1..63e265cb38 100644
> --- a/target/i386/seg_helper.c
> +++ b/target/i386/seg_helper.c
> @@ -991,11 +991,11 @@ void helper_syscall(CPUX86State *env, int next_eip_addend)
> int code64;
>
> env->regs[R_ECX] = env->eip + next_eip_addend;
> - env->regs[11] = cpu_compute_eflags(env);
> + env->regs[11] = cpu_compute_eflags(env) & ~RF_MASK;
>
> code64 = env->hflags & HF_CS64_MASK;
>
> - env->eflags &= ~env->fmask;
> + env->eflags &= ~(env->fmask | RF_MASK);
> cpu_load_eflags(env, env->eflags, 0);
> cpu_x86_load_seg_cache(env, R_CS, selector & 0xfffc,
> 0, 0xffffffff,
>
Queued, thanks.
Paolo
^ permalink raw reply [flat|nested] 2+ messages in thread
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2018-10-19 12:27 ` Paolo Bonzini
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