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| author | Josh Poimboeuf <jpoimboe@redhat.com> | 2019-07-15 11:51:39 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-08-11 12:20:48 +0200 |
| commit | 967858f2f222dd140429c70d855e85dafcc89c29 (patch) | |
| tree | 5d697bbd1b1532feafab6cbeeae0bf50316fb91b /Makefile | |
| parent | 73e2c1bd2714f902c5ee290445579b79afc6a0e6 (diff) | |
x86/entry/64: Use JMP instead of JMPQ
commit 64dbc122b20f75183d8822618c24f85144a5a94d upstream.
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>
[bwh: Backported to 4.4: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Makefile')
0 files changed, 0 insertions, 0 deletions