linux/tools
Josh Poimboeuf cca84cb129 objtool/klp: Fix position-dependent checksums for non-relocated jumps/calls
When computing klp checksums, instructions with non-relocated jump/call
destination offsets are problematic because the offset values can change
when surrounding code has moved, causing the function to be incorrectly
marked as changed.

Specifically, that includes jumps from alternatives to the end of the
alternative, which from objtool's perspective are jumps to the end of
the alternative instruction block in the original function.

Note that 'jump_dest' jumps don't include sibling calls (those use
call_dest), nor do they include jumps to/from .cold sub functions (those
are cross-section and need a reloc).

Fix it by hashing the opcode bytes (excluding the immediate operand)
along with a position-independent representation of the destination.
For calls, use the function name, and for jumps, use the destination's
offset within its function.

[Note the "9 bit hole" comment was wrong: it has been 8 bits since
commit 70589843b3 ("objtool: Add option to trace function validation")
added the 'trace' field.  Adding the 4-bit 'immediate_len' field now
leaves a 4-bit hole.]

Fixes: 0d83da43b1 ("objtool/klp: Add --checksum option to generate per-function checksums")
Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2026-05-04 21:16:06 -07:00
..
accounting tools/accounting: handle truncated taskstats netlink messages 2026-04-15 02:15:02 -07:00
arch Arm: 2026-04-17 07:18:03 -07:00
bootconfig tools/bootconfig: fix fd leak in load_xbc_file() on fstat failure 2026-03-19 08:43:06 +09:00
bpf bpftool: add missing fsession to the usage and docs of bpftool 2026-04-12 12:42:38 -07:00
build perf tools updates for 7.1 2026-04-18 09:24:56 -07:00
certs
cgroup
counter
crypto
debugging
dma tools/dma: Add dma_map_sg support 2026-03-04 11:22:05 +01:00
docs docs: kdoc_diff: add a helper tool to help checking kdoc regressions 2026-03-30 10:54:13 -06:00
firewire
firmware
gpio
hv tools: hv: Fix cross-compilation 2026-04-14 04:43:26 +00:00
iio
include memblock: updates for 7.0-rc1 2026-04-18 11:29:14 -07:00
kvm/kvm_stat
laptop
leds
lib Crypto library fix and documentation update for 7.1 2026-04-21 11:46:22 -07:00
memory-model
mm
net tools: ynl: add sample for wireguard 2026-04-14 11:48:04 -07:00
objtool objtool/klp: Fix position-dependent checksums for non-relocated jumps/calls 2026-05-04 21:16:06 -07:00
pcmcia
perf perf tools updates for 7.1 2026-04-18 09:24:56 -07:00
power Power Utilities 2026.04.25 2026-04-25 16:58:34 -07:00
rcu
sched
sched_ext tools/sched_ext: scx_qmap: Silence task_ctx lookup miss 2026-04-21 06:18:58 -10:00
scripts Kbuild/Kconfig updates for 7.1 2026-04-14 09:18:40 -07:00
sound
spi
testing Assorted arm64, ACPI and kselftest fixes for 7.1-rc2: 2026-05-01 16:32:42 -07:00
thermal
time
tracing RTLA patches for v7.1: 2026-04-15 17:48:24 -07:00
unittests docs: kdoc: better handle source when producing YAML output 2026-03-25 13:36:46 -06:00
usb usbip: tools: add hint when no exported devices are found 2026-04-11 12:02:00 +02:00
verification rv: Allow epoll in rtapp-sleep monitor 2026-04-01 15:18:30 +02:00
virtio
wmi
workqueue tools/workqueue: add CACHE_SHARD support to wq_dump.py 2026-04-01 10:24:18 -10:00
writeback
Makefile