[PATCH 23/24] ARM64:ILP32: Fix signal return for ILP32 when the user modified the signal stack.
From: Andrew Pinski <hidden>
Date: 2014-05-24 07:10:52
Also in:
lkml
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
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). Thanks, Andrew Pinski Signed-off-by: Andrew Pinski <redacted> --- arch/arm64/kernel/signal.c | 12 ++++++++++++ 1 files changed, 12 insertions(+), 0 deletions(-)
diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
index fd49b58..d5682b6 100644
--- a/arch/arm64/kernel/signal.c
+++ b/arch/arm64/kernel/signal.c@@ -34,6 +34,7 @@ #include <asm/fpsimd.h> #include <asm/signal32.h> #include <asm/vdso.h> +#include <asm/syscalls.h> /* * Do a signal return; undo the signal stack. These are aligned to 128-bit.
@@ -149,6 +150,17 @@ 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