[Qemu-devel] [PATCH] linux-user: Fix incorrect offset of tuc_stack in ARM do_sigframe_return_v2

[Qemu-devel] [PATCH] linux-user: Fix incorrect offset of tuc_stack in ARM do_sigframe_return_v2

[Timothy E Baldwin]

struct target_ucontext_v2 is not at the begining of the signal frame,
therefore do_sigaltstack was being passed bogus arguments.

As the offset depends on the type of signal frame fixed by passing in the
beginning of the context from do_sigreturn_v2 and do_rt_sigreturn_v2.

Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
---

Changes since v2:
 Change do_sigreturn_v2 and do_rt_sigreturn_v2 to pass in context.
 Rename frame_addr to context_addr

 linux-user/signal.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/linux-user/signal.c b/linux-user/signal.c
index 9a4d894..b5cdb25 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -2035,7 +2035,8 @@ static abi_ulong *restore_sigframe_v2_iwmmxt(CPUARMState *env,
     return (abi_ulong*)(iwmmxtframe + 1);
 }
 
-static int do_sigframe_return_v2(CPUARMState *env, target_ulong frame_addr,
+static int do_sigframe_return_v2(CPUARMState *env,
+                                 target_ulong context_addr,
                                  struct target_ucontext_v2 *uc)
 {
     sigset_t host_set;
@@ -2062,8 +2063,11 @@ static int do_sigframe_return_v2(CPUARMState *env, target_ulong frame_addr,
         }
     }
 
-    if (do_sigaltstack(frame_addr + offsetof(struct target_ucontext_v2, tuc_stack), 0, get_sp_from_cpustate(env)) == -EFAULT)
+    if (do_sigaltstack(context_addr
+                       + offsetof(struct target_ucontext_v2, tuc_stack),
+                       0, get_sp_from_cpustate(env)) == -EFAULT) {
         return 1;
+    }
 
 #if 0
     /* Send SIGTRAP if we're single-stepping */
@@ -2094,7 +2098,10 @@ static long do_sigreturn_v2(CPUARMState *env)
         goto badframe;
     }
 
-    if (do_sigframe_return_v2(env, frame_addr, &frame->uc)) {
+    if (do_sigframe_return_v2(env,
+                              frame_addr
+                              + offsetof(struct sigframe_v2, uc),
+                              &frame->uc)) {
         goto badframe;
     }
 
@@ -2181,7 +2188,10 @@ static long do_rt_sigreturn_v2(CPUARMState *env)
         goto badframe;
     }
 
-    if (do_sigframe_return_v2(env, frame_addr, &frame->uc)) {
+    if (do_sigframe_return_v2(env,
+                              frame_addr
+                              + offsetof(struct rt_sigframe_v2, uc),
+                              &frame->uc)) {
         goto badframe;
     }
 
-- 
2.9.3

Re: [Qemu-devel] [PATCH] linux-user: Fix incorrect offset of tuc_stack in ARM do_sigframe_return_v2

[Peter Maydell]

On 9 September 2016 at 19:35, Timothy E Baldwin
<T.E.Baldwin99@members.leeds.ac.uk> wrote:
> struct target_ucontext_v2 is not at the begining of the signal frame,
> therefore do_sigaltstack was being passed bogus arguments.
>
> As the offset depends on the type of signal frame fixed by passing in the
> beginning of the context from do_sigreturn_v2 and do_rt_sigreturn_v2.
>
> Suggested-by: Peter Maydell <peter.maydell@linaro.org>
> Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
> ---

Thanks for the respin.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM

Re: [Qemu-devel] [PATCH] linux-user: Fix incorrect offset of tuc_stack in ARM do_sigframe_return_v2

[Riku Voipio]

On Fri, Sep 09, 2016 at 09:02:55PM +0100, Peter Maydell wrote:
> On 9 September 2016 at 19:35, Timothy E Baldwin
> <T.E.Baldwin99@members.leeds.ac.uk> wrote:
> > struct target_ucontext_v2 is not at the begining of the signal frame,
> > therefore do_sigaltstack was being passed bogus arguments.
> >
> > As the offset depends on the type of signal frame fixed by passing in the
> > beginning of the context from do_sigreturn_v2 and do_rt_sigreturn_v2.
> >
> > Suggested-by: Peter Maydell <peter.maydell@linaro.org>
> > Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
> > ---
> 
> Thanks for the respin.
> 
> Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

Applied to linux-user que, thanks!