linux-kernel - [tip: x86/urgent] x86/traps: Correct exc_general_protection() and math

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Message-ID: <161796922230.29796.17695217108171353828.tip-bot2@tip-bot2>
Date:   Fri, 09 Apr 2021 11:53:42 -0000
From:   "tip-bot2 for Thomas Tai" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Thomas Tai <thomas.tai@...cle.com>, Borislav Petkov <bp@...e.de>,
        Alexandre Chartre <alexandre.chartre@...cle.com>,
        x86@...nel.org, linux-kernel@...r.kernel.org
Subject: [tip: x86/urgent] x86/traps: Correct exc_general_protection() and
 math_error() return paths

The following commit has been merged into the x86/urgent branch of tip:

Commit-ID:     632a1c209b8773cb0119fe3aada9f1db14fa357c
Gitweb:        https://git.kernel.org/tip/632a1c209b8773cb0119fe3aada9f1db14fa357c
Author:        Thomas Tai <thomas.tai@...cle.com>
AuthorDate:    Thu, 08 Apr 2021 13:28:33 -04:00
Committer:     Borislav Petkov <bp@...e.de>
CommitterDate: Fri, 09 Apr 2021 13:45:09 +02:00

x86/traps: Correct exc_general_protection() and math_error() return paths

Commit

  334872a09198 ("x86/traps: Attempt to fixup exceptions in vDSO before signaling")

added return statements which bypass calling cond_local_irq_disable().

According to

  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.

 [ bp: Massage commit message. ]

Fixes: 334872a09198 ("x86/traps: Attempt to fixup exceptions in vDSO before signaling")
Signed-off-by: Thomas Tai <thomas.tai@...cle.com>
Signed-off-by: Borislav Petkov <bp@...e.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@...cle.com>
Link: https://lkml.kernel.org/r/1617902914-83245-1-git-send-email-thomas.tai@oracle.com
---
 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 @@ DEFINE_IDTENTRY_ERRORCODE(exc_general_protection)
 		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));