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| author | Peter Zijlstra <[email protected]> | 2023-01-23 20:59:17 +0000 |
|---|---|---|
| committer | Ingo Molnar <[email protected]> | 2023-01-31 14:05:31 +0000 |
| commit | ac0ee0a9560c97fa5fe1409e450c2425d4ebd17a (patch) | |
| tree | 504f81bb70d25dd873e14d74ae5064a043dc8351 /tools/perf/scripts/python/net_dropmonitor.py | |
| parent | x86/alternatives: Introduce int3_emulate_jcc() (diff) | |
| download | kernel-ac0ee0a9560c97fa5fe1409e450c2425d4ebd17a.tar.gz kernel-ac0ee0a9560c97fa5fe1409e450c2425d4ebd17a.zip | |
x86/alternatives: Teach text_poke_bp() to patch Jcc.d32 instructions
In order to re-write Jcc.d32 instructions text_poke_bp() needs to be
taught about them.
The biggest hurdle is that the whole machinery is currently made for 5
byte instructions and extending this would grow struct text_poke_loc
which is currently a nice 16 bytes and used in an array.
However, since text_poke_loc contains a full copy of the (s32)
displacement, it is possible to map the Jcc.d32 2 byte opcodes to
Jcc.d8 1 byte opcode for the int3 emulation.
This then leaves the replacement bytes; fudge that by only storing the
last 5 bytes and adding the rule that 'length == 6' instruction will
be prefixed with a 0x0f byte.
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Reviewed-by: Masami Hiramatsu (Google) <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Diffstat (limited to 'tools/perf/scripts/python/net_dropmonitor.py')
0 files changed, 0 insertions, 0 deletions