[PATCH 1/2] x86/traps: call cond_local_irq_disable before returning from exc_general_protection and math_error

From: Thomas Tai
Date: Thu Apr 08 2021 - 13:27:59 EST


This fixes commit 334872a09198 ("x86/traps: Attempt to fixup exceptions
in vDSO before signaling") which added return statements without calling
cond_local_irq_disable(). According to commit ca4c6a9858c2
("x86/traps: Make interrupt enable/disable symmetric in C code"),
cond_local_irq_disable() is needed because the ASM return code no
longer disables interrupts. Follow the existing code as an example to
use "goto exit" instead of "return" statement.

Signed-off-by: Thomas Tai <thomas.tai@xxxxxxxxxx>
---
arch/x86/kernel/traps.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index ac1874a..651e3e5 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -556,7 +556,7 @@ static enum kernel_gp_hint get_kernel_gp_address(struct pt_regs *regs,
tsk->thread.trap_nr = X86_TRAP_GP;

if (fixup_vdso_exception(regs, X86_TRAP_GP, error_code, 0))
- return;
+ goto exit;

show_signal(tsk, SIGSEGV, "", desc, regs, error_code);
force_sig(SIGSEGV);
@@ -1057,7 +1057,7 @@ static void math_error(struct pt_regs *regs, int trapnr)
goto exit;

if (fixup_vdso_exception(regs, trapnr, 0, 0))
- return;
+ goto exit;

force_sig_fault(SIGFPE, si_code,
(void __user *)uprobe_get_trap_addr(regs));
--
1.8.3.1