Commit 26920a29 authored by Jose Ricardo Ziviani's avatar Jose Ricardo Ziviani Committed by Laurent Vivier
Browse files

linux-user: fill target sigcontext struct accordingly 



A segfault is noticed when an emulated program uses any of ucontext
regs fields. Risu detected this issue in the following operation when
handling a signal:
  ucontext_t *uc = (ucontext_t*)uc;
  uc->uc_mcontext.regs->nip += 4;

but this works fine:
  uc->uc_mcontext.gp_regs[PT_NIP] += 4;

This patch set regs to a valid location as well as other sigcontext
fields.

Signed-off-by: default avatarJose Ricardo Ziviani <joserz@linux.vnet.ibm.com>
Reviewed-by: default avatarLaurent Vivier <laurent@vivier.eu>
Message-Id: <1485900317-3256-1-git-send-email-joserz@linux.vnet.ibm.com>
Signed-off-by: default avatarLaurent Vivier <laurent@vivier.eu>
parent 35f2fd04

linux-user/signal.c

+5 −0
Original line number Diff line number Diff line
@@ -5155,6 +5155,7 @@ static void setup_rt_frame(int sig, struct target_sigaction *ka, 
    target_ulong rt_sf_addr, newsp = 0;

    int i, err = 0;

#if defined(TARGET_PPC64)

    struct target_sigcontext *sc = 0;

    struct image_info *image = ((TaskState *)thread_cpu->opaque)->info;

#endif
@@ -5183,6 +5184,10 @@ static void setup_rt_frame(int sig, struct target_sigaction *ka, 
#if defined(TARGET_PPC64)

    mctx = &rt_sf->uc.tuc_sigcontext.mcontext;

    trampptr = &rt_sf->trampoline[0];



    sc = &rt_sf->uc.tuc_sigcontext;

    __put_user(h2g(mctx), &sc->regs);

    __put_user(sig, &sc->signal);

#else

    mctx = &rt_sf->uc.tuc_mcontext;

    trampptr = (uint32_t *)&rt_sf->uc.tuc_mcontext.tramp;