linux/debian/patches-rt/0241-x86-lazy-preempt-use-p...

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1.7 KiB
Diff

From c7caac7131763a2c0b09587010acd14798810502 Mon Sep 17 00:00:00 2001
Message-Id: <c7caac7131763a2c0b09587010acd14798810502.1601675152.git.zanussi@kernel.org>
In-Reply-To: <5b5a156f9808b1acf1205606e03da117214549ea.1601675151.git.zanussi@kernel.org>
References: <5b5a156f9808b1acf1205606e03da117214549ea.1601675151.git.zanussi@kernel.org>
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Tue, 26 Feb 2019 14:53:49 +0100
Subject: [PATCH 241/333] x86: lazy-preempt: use proper return label on
32bit-x86
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.148-rt64.tar.xz
The lazy-preempt uses the wrong return label in case preemption isn't
possible. This results crash while returning to the kernel.
Use the correct return label if preemption isn' possible.
Reported-by: Andri Yngvason <andri@yngvason.is>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
arch/x86/entry/entry_32.S | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index 324b7539eaab..d8b40085c2b8 100644
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -759,15 +759,15 @@ ENTRY(resume_kernel)
# atleast preempt count == 0 ?
cmpl $_PREEMPT_ENABLED,PER_CPU_VAR(__preempt_count)
- jne restore_all
+ jne restore_all_kernel
movl PER_CPU_VAR(current_task), %ebp
cmpl $0,TASK_TI_preempt_lazy_count(%ebp) # non-zero preempt_lazy_count ?
- jnz restore_all
+ jnz restore_all_kernel
testl $_TIF_NEED_RESCHED_LAZY, TASK_TI_flags(%ebp)
- jz restore_all
- test_int_off:
+ jz restore_all_kernel
+test_int_off:
#endif
testl $X86_EFLAGS_IF, PT_EFLAGS(%esp) # interrupts off (exception path) ?
jz restore_all_kernel
--
2.17.1