From 64dbc122b20f75183d8822618c24f85144a5a94d Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Mon, 15 Jul 2019 11:51:39 -0500 Subject: x86/entry/64: Use JMP instead of JMPQ Somehow the swapgs mitigation entry code patch ended up with a JMPQ instruction instead of JMP, where only the short jump is needed. Some assembler versions apparently fail to optimize JMPQ into a two-byte JMP when possible, instead always using a 7-byte JMP with relocation. For some reason that makes the entry code explode with a #GP during boot. Change it back to "JMP" as originally intended. Fixes: 18ec54fdd6d1 ("x86/speculation: Prepare entry code for Spectre v1 swapgs mitigations") Signed-off-by: Josh Poimboeuf Signed-off-by: Thomas Gleixner --- arch/x86/entry/entry_64.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 57a0d96d6beb..b043c754d978 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -549,7 +549,7 @@ ENTRY(interrupt_entry) UNWIND_HINT_FUNC movq (%rdi), %rdi - jmpq 2f + jmp 2f 1: FENCE_SWAPGS_KERNEL_ENTRY 2: -- cgit v1.2.3