On Tue, Feb 28, 2017 at 11:22:54AM +0100, Laurent Vivier wrote: > Le 28/02/2017 à 02:09, David Gibson a écrit : > > On Wed, Feb 01, 2017 at 09:43:57PM +0100, Laurent Vivier wrote: > >> Le 31/01/2017 à 23:05, Jose Ricardo Ziviani a écrit : > >>> 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: Jose Ricardo Ziviani <jos...@linux.vnet.ibm.com> > >>> --- > >>> linux-user/signal.c | 5 +++++ > >>> 1 file changed, 5 insertions(+) > >>> > >>> diff --git a/linux-user/signal.c b/linux-user/signal.c > >>> index 5064de0..8209539 100644 > >>> --- a/linux-user/signal.c > >>> +++ b/linux-user/signal.c > >>> @@ -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; > >>> > >> > >> Reviewed-by: Laurent Vivier <laur...@vivier.eu> > >> > >> This is correct, but QEMU and kernel implementation are really > >> different. > > > > Hi David, > > > Laurent, I'm a bit clear on what the upshot is here. > > > > Should I merge the patch above? > > I've already included this patch in a linux-user pull request a couple > of weeks ago, and it is now in the master. > > So you have nothing to do :)
Excellent, thanks for the clarification.
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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