| Message ID | 20220503225157.1696774-2-iii@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | linux-user/s390x: Fix unwinding from signal handlers | expand |
On 04.05.22 00:51, Ilya Leoshkevich wrote: > Commit 31330e6cecfd ("linux-user/s390x: Implement setup_sigtramp") > removed an unused field from rt_sigframe, disturbing offsets of other > fields and breaking unwinding from signal handlers (e.g. libgcc's > s390_fallback_frame() relies on this struct having a specific layout). > Restore the field and add a comment. > > Reported-by: Ulrich Weigand <ulrich.weigand@de.ibm.com> > Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> > Fixes: 31330e6cecfd ("linux-user/s390x: Implement setup_sigtramp") > --- > linux-user/s390x/signal.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/linux-user/s390x/signal.c b/linux-user/s390x/signal.c > index f47713e04a..4979c4b017 100644 > --- a/linux-user/s390x/signal.c > +++ b/linux-user/s390x/signal.c > @@ -84,6 +84,11 @@ struct target_ucontext { > > typedef struct { > uint8_t callee_used_stack[__SIGNAL_FRAMESIZE]; > + /* > + * This field is no longer initialized by the kernel, but it's still a part > + * of the ABI. > + */ > + uint16_t svc_insn; > struct target_siginfo info; > struct target_ucontext uc; > } rt_sigframe; Reviewed-by: David Hildenbrand <david@redhat.com>
On 5/3/22 17:51, Ilya Leoshkevich wrote: > Commit 31330e6cecfd ("linux-user/s390x: Implement setup_sigtramp") > removed an unused field from rt_sigframe, disturbing offsets of other > fields and breaking unwinding from signal handlers (e.g. libgcc's > s390_fallback_frame() relies on this struct having a specific layout). > Restore the field and add a comment. > > Reported-by: Ulrich Weigand<ulrich.weigand@de.ibm.com> > Signed-off-by: Ilya Leoshkevich<iii@linux.ibm.com> > Fixes: 31330e6cecfd ("linux-user/s390x: Implement setup_sigtramp") > --- > linux-user/s390x/signal.c | 5 +++++ > 1 file changed, 5 insertions(+) Reviewed-by: Richard Henderson <richard.henderson@linaro.org> r~
diff --git a/linux-user/s390x/signal.c b/linux-user/s390x/signal.c index f47713e04a..4979c4b017 100644 --- a/linux-user/s390x/signal.c +++ b/linux-user/s390x/signal.c @@ -84,6 +84,11 @@ struct target_ucontext { typedef struct { uint8_t callee_used_stack[__SIGNAL_FRAMESIZE]; + /* + * This field is no longer initialized by the kernel, but it's still a part + * of the ABI. + */ + uint16_t svc_insn; struct target_siginfo info; struct target_ucontext uc; } rt_sigframe;
Commit 31330e6cecfd ("linux-user/s390x: Implement setup_sigtramp") removed an unused field from rt_sigframe, disturbing offsets of other fields and breaking unwinding from signal handlers (e.g. libgcc's s390_fallback_frame() relies on this struct having a specific layout). Restore the field and add a comment. Reported-by: Ulrich Weigand <ulrich.weigand@de.ibm.com> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Fixes: 31330e6cecfd ("linux-user/s390x: Implement setup_sigtramp") --- linux-user/s390x/signal.c | 5 +++++ 1 file changed, 5 insertions(+)