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authorJosh Poimboeuf <jpoimboe@redhat.com>2019-07-15 18:51:39 +0200
committerThomas Gleixner <tglx@linutronix.de>2019-07-17 15:37:14 +0200
commit64dbc122b20f75183d8822618c24f85144a5a94d (patch)
tree49399e44a25bed365000cf7ae9af240db1065350 /arch/x86
parentx86/speculation: Enable Spectre v1 swapgs mitigations (diff)
downloadlinux-64dbc122b20f75183d8822618c24f85144a5a94d.tar.xz
linux-64dbc122b20f75183d8822618c24f85144a5a94d.zip
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 <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/entry/entry_64.S2
1 files changed, 1 insertions, 1 deletions
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: