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| author | Al Viro <viro@zeniv.linux.org.uk> | 2012-11-18 22:27:03 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-12-03 11:38:01 -0800 |
| commit | cbda50306446b3f359bbf2874a99979990b0627c (patch) | |
| tree | 2e374f90de242cbb3fa6852b3c4b83bdbb48e713 /arch | |
| parent | 1abb8a53f9e49838d8b5b4b8e57c135378fa1bf6 (diff) | |
| download | lwn-cbda50306446b3f359bbf2874a99979990b0627c.tar.gz lwn-cbda50306446b3f359bbf2874a99979990b0627c.zip | |
sparc64: not any error from do_sigaltstack() should fail rt_sigreturn()
commit fae2ae2a900a5c7bb385fe4075f343e7e2d5daa2 upstream.
If a signal handler is executed on altstack and another signal comes,
we will end up with rt_sigreturn() on return from the second handler
getting -EPERM from do_sigaltstack(). It's perfectly OK, since we
are not asking to change the settings; in fact, they couldn't have been
changed during the second handler execution exactly because we'd been
on altstack all along. 64bit sigreturn on sparc treats any error from
do_sigaltstack() as "SIGSEGV now"; we need to switch to the same semantics
we are using on other architectures.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/sparc/kernel/signal_64.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/arch/sparc/kernel/signal_64.c b/arch/sparc/kernel/signal_64.c index 867de2f8189c..689e1ba62809 100644 --- a/arch/sparc/kernel/signal_64.c +++ b/arch/sparc/kernel/signal_64.c @@ -295,9 +295,7 @@ void do_rt_sigreturn(struct pt_regs *regs) err |= restore_fpu_state(regs, fpu_save); err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t)); - err |= do_sigaltstack(&sf->stack, NULL, (unsigned long)sf); - - if (err) + if (err || do_sigaltstack(&sf->stack, NULL, (unsigned long)sf) == -EFAULT) goto segv; err |= __get_user(rwin_save, &sf->rwin_save); |