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author | Steven Rostedt <srostedt@redhat.com> | 2012-01-26 23:06:45 (GMT) |
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committer | Steven Rostedt <rostedt@goodmis.org> | 2013-08-07 01:16:33 (GMT) |
commit | c3c7f14a116c24d6fba185c95cd7454f3764f8a9 (patch) | |
tree | 1766dcc9afbc1a1417c2783a601c7c7973b71eef /arch/x86/mm/testmmiotrace.c | |
parent | ad81f0545ef01ea651886dddac4bef6cec930092 (diff) | |
download | linux-c3c7f14a116c24d6fba185c95cd7454f3764f8a9.tar.xz |
x86/jump-label: Use best default nops for inital jump label calls
As specified by H. Peter Anvin, the best nops for x86 without knowing
the running computer is:
32bit:
0x3e, 0x8d, 0x74, 0x26, 0x00 also known as GENERIC_NOP5_ATOMIC
64bit:
0x0f, 0x1f, 0x44, 0x00, 0x00 also known as P6_NOP5_ATOMIC
Currently the default nop that is used by jump label is:
0xe9 0x00 0x00 0x00 0x00
Which is really a 5byte jump to the next position.
It's better to use a real nop than a jmp.
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Jason Baron <jbaron@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'arch/x86/mm/testmmiotrace.c')
0 files changed, 0 insertions, 0 deletions