Commit 40ad2199 authored Nov 20, 2019 by Peter Zijlstra

x86/entry/32: Fix IRET exception



As reported by Lai, the commit 3c88c692 ("x86/stackframe/32:
Provide consistent pt_regs") wrecked the IRET EXTABLE entry by making
.Lirq_return not point at IRET.

Fix this by placing IRET_FRAME in RESTORE_REGS, to mirror how
FIXUP_FRAME is part of SAVE_ALL.

Fixes: 3c88c692 ("x86/stackframe/32: Provide consistent pt_regs")
Reported-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: stable@kernel.org

parent 880a98c3

arch/x86/entry/entry_32.S

+1 −1

Original line number	Diff line number	Diff line
		@@ -357,6 +357,7 @@
		2: popl %es
		3: popl %fs
		POP_GS \pop
		IRET_FRAME
		.pushsection .fixup, "ax"
		4: movl $0, (%esp)
		jmp 1b
		@@ -1075,7 +1076,6 @@ restore_all:
		/* Restore user state */
		RESTORE_REGS pop=4 # skip orig_eax/error_code
		.Lirq_return:
		IRET_FRAME
		/*
		* ARCH_HAS_MEMBARRIER_SYNC_CORE rely on IRET core serialization
		* when returning from IPI handler and when returning from

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