Re: [Qemu-devel] [PATCH v2] linux-user/signal.c: Generate opcode data for restorer in setup_rt_frame

[Laurent Vivier]

Le 29/03/2016 15:53, cheng...@emindsoft.com.cn a écrit :
> From: Chen Gang 
> 
> Original implementation uses do_rt_sigreturn directly in host space,
> when a guest program is in unwind procedure in guest space, it will get
> an incorrect restore address, then causes unwind failure.
> 
> Also cleanup the original incorrect indentation.
> 
> Signed-off-by: Chen Gang 

Reviewed-by: Laurent Vivier 

> ---
>  linux-user/signal.c | 12 ++--
>  1 file changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/linux-user/signal.c b/linux-user/signal.c
> index 96e86c0..e487f9e 100644
> --- a/linux-user/signal.c
> +++ b/linux-user/signal.c
> @@ -5559,8 +5559,13 @@ struct target_rt_sigframe {
>  unsigned char save_area[16]; /* caller save area */
>  struct target_siginfo info;
>  struct target_ucontext uc;
> +abi_ulong retcode[2];
>  };
>  
> +#define INSN_MOVELI_R10_139  0x00045fe551483000ULL /* { moveli r10, 139 } */
> +#define INSN_SWINT1  0x286b180051485000ULL /* { swint1 } */
> +
> +
>  static void setup_sigcontext(struct target_sigcontext *sc,
>   CPUArchState *env, int signo)
>  {
> @@ -5636,9 +5641,12 @@ static void setup_rt_frame(int sig, struct 
> target_sigaction *ka,
>  __put_user(target_sigaltstack_used.ss_size, 
> >uc.tuc_stack.ss_size);
>  setup_sigcontext(>uc.tuc_mcontext, env, info->si_signo);
>  
> -restorer = (unsigned long) do_rt_sigreturn;
>  if (ka->sa_flags & TARGET_SA_RESTORER) {
> -restorer = (unsigned long) ka->sa_restorer;
> +restorer = (unsigned long) ka->sa_restorer;
> +} else {
> +__put_user(INSN_MOVELI_R10_139, >retcode[0]);
> +__put_user(INSN_SWINT1, >retcode[1]);
> +restorer = frame_addr + offsetof(struct target_rt_sigframe, retcode);
>  }
>  env->pc = (unsigned long) ka->_sa_handler;
>  env->regs[TILEGX_R_SP] = (unsigned long) frame;
> 

[Qemu-devel] [PATCH v2] linux-user/signal.c: Generate opcode data for restorer in setup_rt_frame

[chengang]

From: Chen Gang 

Original implementation uses do_rt_sigreturn directly in host space,
when a guest program is in unwind procedure in guest space, it will get
an incorrect restore address, then causes unwind failure.

Also cleanup the original incorrect indentation.

Signed-off-by: Chen Gang 
---
 linux-user/signal.c | 12 ++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/linux-user/signal.c b/linux-user/signal.c
index 96e86c0..e487f9e 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -5559,8 +5559,13 @@ struct target_rt_sigframe {
 unsigned char save_area[16]; /* caller save area */
 struct target_siginfo info;
 struct target_ucontext uc;
+abi_ulong retcode[2];
 };
 
+#define INSN_MOVELI_R10_139  0x00045fe551483000ULL /* { moveli r10, 139 } */
+#define INSN_SWINT1  0x286b180051485000ULL /* { swint1 } */
+
+
 static void setup_sigcontext(struct target_sigcontext *sc,
  CPUArchState *env, int signo)
 {
@@ -5636,9 +5641,12 @@ static void setup_rt_frame(int sig, struct 
target_sigaction *ka,
 __put_user(target_sigaltstack_used.ss_size, >uc.tuc_stack.ss_size);
 setup_sigcontext(>uc.tuc_mcontext, env, info->si_signo);
 
-restorer = (unsigned long) do_rt_sigreturn;
 if (ka->sa_flags & TARGET_SA_RESTORER) {
-restorer = (unsigned long) ka->sa_restorer;
+restorer = (unsigned long) ka->sa_restorer;
+} else {
+__put_user(INSN_MOVELI_R10_139, >retcode[0]);
+__put_user(INSN_SWINT1, >retcode[1]);
+restorer = frame_addr + offsetof(struct target_rt_sigframe, retcode);
 }
 env->pc = (unsigned long) ka->_sa_handler;
 env->regs[TILEGX_R_SP] = (unsigned long) frame;
-- 
1.9.3