From mboxrd@z Thu Jan 1 00:00:00 1970 From: apinski@cavium.com (Andrew Pinski) Date: Wed, 3 Sep 2014 14:19:16 -0700 Subject: [PATCH 22/24] ARM64:ILP32: Fix signal return for ILP32 when the user modified the signal stack In-Reply-To: <1409779158-30963-1-git-send-email-apinski@cavium.com> References: <1409779158-30963-1-git-send-email-apinski@cavium.com> Message-ID: <1409779158-30963-23-git-send-email-apinski@cavium.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org If the user decided to change the stack_t that was on the stack when returning from the signal handler, the stack_t's padding for ILP32 might be not zero. So we need to use the syscall version of restore_altstack (ilp32_sys_sigaltstack). Signed-off-by: Andrew Pinski --- arch/arm64/kernel/signal.c | 14 ++++++++++++++ 1 files changed, 14 insertions(+), 0 deletions(-) diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index 5311147..6316d54 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -35,6 +35,7 @@ #include #include #include +#include /* * Do a signal return; undo the signal stack. These are aligned to 128-bit. @@ -149,6 +150,19 @@ asmlinkage long sys_rt_sigreturn(struct pt_regs *regs) if (restore_sigframe(regs, frame)) goto badframe; +#ifdef CONFIG_ARM64_ILP32 + /* + * ILP32 has to be handled "special" due to maybe not zeroing out + * the upper 32bits of the pointer if the user changed the frame. + */ + if (is_ilp32_compat_task()) { + if (ilp32_sys_sigaltstack(&frame->uc.uc_stack, + NULL) == -EFAULT) + goto badframe; + return regs->regs[0]; + } +#endif + if (restore_altstack(&frame->uc.uc_stack)) goto badframe; -- 1.7.2.5