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authorChristian Ruppert <christian.ruppert@abilis.com>2013-10-02 11:13:38 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-10-18 07:45:45 -0700
commit19a420033da02200c424adfa3a7b9eed6e3a6dc2 (patch)
tree1cb4383772ec6393acdad086db77fb63526316f0 /arch
parent0c06a0a693a5baaeacdb4c9485d5d6d490ea8a23 (diff)
downloadvexpress-lsk-19a420033da02200c424adfa3a7b9eed6e3a6dc2.tar.gz
ARC: Fix signal frame management for SA_SIGINFO
commit 10469350e345599dfef3fa78a7c19fb230e674c1 upstream. Previously, when a signal was registered with SA_SIGINFO, parameters 2 and 3 of the signal handler were written to registers r1 and r2 before the register set was saved. This led to corruption of these two registers after returning from the signal handler (the wrong values were restored). With this patch, registers are now saved before any parameters are passed, thus maintaining the processor state from before signal entry. Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/arc/kernel/signal.c25
1 files changed, 13 insertions, 12 deletions
diff --git a/arch/arc/kernel/signal.c b/arch/arc/kernel/signal.c
index ee6ef2f60a2..7e95e1a8651 100644
--- a/arch/arc/kernel/signal.c
+++ b/arch/arc/kernel/signal.c
@@ -101,7 +101,6 @@ SYSCALL_DEFINE0(rt_sigreturn)
{
struct rt_sigframe __user *sf;
unsigned int magic;
- int err;
struct pt_regs *regs = current_pt_regs();
/* Always make any pending restarted system calls return -EINTR */
@@ -119,15 +118,16 @@ SYSCALL_DEFINE0(rt_sigreturn)
if (!access_ok(VERIFY_READ, sf, sizeof(*sf)))
goto badframe;
- err = restore_usr_regs(regs, sf);
- err |= __get_user(magic, &sf->sigret_magic);
- if (err)
+ if (__get_user(magic, &sf->sigret_magic))
goto badframe;
if (unlikely(is_do_ss_needed(magic)))
if (restore_altstack(&sf->uc.uc_stack))
goto badframe;
+ if (restore_usr_regs(regs, sf))
+ goto badframe;
+
/* Don't restart from sigreturn */
syscall_wont_restart(regs);
@@ -191,6 +191,15 @@ setup_rt_frame(int signo, struct k_sigaction *ka, siginfo_t *info,
return 1;
/*
+ * w/o SA_SIGINFO, struct ucontext is partially populated (only
+ * uc_mcontext/uc_sigmask) for kernel's normal user state preservation
+ * during signal handler execution. This works for SA_SIGINFO as well
+ * although the semantics are now overloaded (the same reg state can be
+ * inspected by userland: but are they allowed to fiddle with it ?
+ */
+ err |= stash_usr_regs(sf, regs, set);
+
+ /*
* SA_SIGINFO requires 3 args to signal handler:
* #1: sig-no (common to any handler)
* #2: struct siginfo
@@ -213,14 +222,6 @@ setup_rt_frame(int signo, struct k_sigaction *ka, siginfo_t *info,
magic = MAGIC_SIGALTSTK;
}
- /*
- * w/o SA_SIGINFO, struct ucontext is partially populated (only
- * uc_mcontext/uc_sigmask) for kernel's normal user state preservation
- * during signal handler execution. This works for SA_SIGINFO as well
- * although the semantics are now overloaded (the same reg state can be
- * inspected by userland: but are they allowed to fiddle with it ?
- */
- err |= stash_usr_regs(sf, regs, set);
err |= __put_user(magic, &sf->sigret_magic);
if (err)
return err;