2019-02-27 18:51:46 +00:00
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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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Date: Tue, 26 Feb 2019 14:53:49 +0100
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2019-11-25 00:04:39 +00:00
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Subject: [PATCH 243/290] x86: lazy-preempt: use proper return label on
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2019-04-08 23:49:20 +00:00
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32bit-x86
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2019-11-25 00:04:39 +00:00
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Origin: https://git.kernel.org/cgit/linux/kernel/git/rt/linux-stable-rt.git/commit?id=8df5629dc5f632aa3559f60a3e53de3615401003
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2019-02-27 18:51:46 +00:00
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The lazy-preempt uses the wrong return label in case preemption isn't
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possible. This results crash while returning to the kernel.
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Use the correct return label if preemption isn' possible.
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Reported-by: Andri Yngvason <andri@yngvason.is>
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Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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---
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2019-04-08 23:49:20 +00:00
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arch/x86/entry/entry_32.S | 8 ++++----
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2019-02-27 18:51:46 +00:00
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1 file changed, 4 insertions(+), 4 deletions(-)
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2019-04-08 23:49:20 +00:00
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diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
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2019-11-25 00:04:39 +00:00
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index 985988227877..d880352e410c 100644
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2019-02-27 18:51:46 +00:00
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--- a/arch/x86/entry/entry_32.S
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+++ b/arch/x86/entry/entry_32.S
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2019-08-18 21:33:52 +00:00
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@@ -775,15 +775,15 @@ ENTRY(resume_kernel)
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2019-02-27 18:51:46 +00:00
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# atleast preempt count == 0 ?
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cmpl $_PREEMPT_ENABLED,PER_CPU_VAR(__preempt_count)
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- jne restore_all
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+ jne restore_all_kernel
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movl PER_CPU_VAR(current_task), %ebp
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cmpl $0,TASK_TI_preempt_lazy_count(%ebp) # non-zero preempt_lazy_count ?
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- jnz restore_all
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+ jnz restore_all_kernel
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testl $_TIF_NEED_RESCHED_LAZY, TASK_TI_flags(%ebp)
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- jz restore_all
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- test_int_off:
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+ jz restore_all_kernel
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+test_int_off:
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#endif
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testl $X86_EFLAGS_IF, PT_EFLAGS(%esp) # interrupts off (exception path) ?
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jz restore_all_kernel
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