linux/tools/perf
Petr Pavlu 833fd800bf x86/retpoline,kprobes: Skip optprobe check for indirect jumps with retpolines and IBT
The kprobes optimization check can_optimize() calls
insn_is_indirect_jump() to detect indirect jump instructions in
a target function. If any is found, creating an optprobe is disallowed
in the function because the jump could be from a jump table and could
potentially land in the middle of the target optprobe.

With retpolines, insn_is_indirect_jump() additionally looks for calls to
indirect thunks which the compiler potentially used to replace original
jumps. This extra check is however unnecessary because jump tables are
disabled when the kernel is built with retpolines. The same is currently
the case with IBT.

Based on this observation, remove the logic to look for calls to
indirect thunks and skip the check for indirect jumps altogether if the
kernel is built with retpolines or IBT. Remove subsequently the symbols
__indirect_thunk_start and __indirect_thunk_end which are no longer
needed.

Dropping this logic indirectly fixes a problem where the range
[__indirect_thunk_start, __indirect_thunk_end] wrongly included also the
return thunk. It caused that machines which used the return thunk as
a mitigation and didn't have it patched by any alternative ended up not
being able to use optprobes in any regular function.

Fixes: 0b53c374b9 ("x86/retpoline: Use -mfunction-return")
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20230711091952.27944-3-petr.pavlu@suse.com
2023-08-14 11:46:51 +02:00
..
arch perf callchain powerpc: Fix addr location init during arch_skip_callchain_idx function 2023-07-24 17:46:11 -03:00
bench perf bench sched messaging: Free contexts on exit 2023-06-12 18:18:14 -03:00
dlfilters perf tools: Fix usage of the verbose variable 2022-12-20 15:16:33 -03:00
Documentation perf lock contention: Add --output option 2023-07-01 10:48:48 -07:00
examples/bpf perf trace: Remove unused bpf map 'syscalls' 2022-11-23 10:30:00 -03:00
include/perf
jvmti
pmu-events perf vendor events amd: Fix large metrics 2023-07-11 11:50:39 -03:00
python
scripts perf python scripting: Get rid of unused import in arm-cs-trace-disasm 2023-06-13 23:40:33 -03:00
tests perf test parse-events: Test complex name has required event format 2023-08-01 00:32:00 -03:00
trace perf beauty: Update copy of linux/socket.h with the kernel sources 2023-07-14 09:59:56 -03:00
ui perf annotation: Switch lock from a mutex to a sharded_mutex 2023-06-20 17:04:21 -07:00
util x86/retpoline,kprobes: Skip optprobe check for indirect jumps with retpolines and IBT 2023-08-14 11:46:51 +02:00
.gitignore perf jevents: Run metric_test.py at compile-time 2023-02-03 17:11:39 -03:00
Build perf script: Fix Python support when no libtraceevent 2023-03-15 10:27:07 -03:00
builtin-annotate.c perf addr_location: Add init/exit/copy functions 2023-06-12 15:57:53 -03:00
builtin-bench.c perf bench: Add missing setlocale() call to allow usage of %'d style formatting 2023-06-05 10:36:58 -03:00
builtin-buildid-cache.c
builtin-buildid-list.c perf util: Move input_name to util 2023-04-10 19:21:31 -03:00
builtin-c2c.c perf callchain: Use pthread keys for tls callchain_cursor 2023-06-12 15:57:54 -03:00
builtin-config.c perf path: Make mkpath thread safe, remove 16384 bytes from .bss 2023-05-28 10:24:14 -03:00
builtin-daemon.c perf tools: Add missing else to cmd_daemon subcommand condition 2023-06-27 12:09:44 -07:00
builtin-data.c perf util: Move input_name to util 2023-04-10 19:21:31 -03:00
builtin-diff.c perf srcline: Optimize comparision against SRCLINE_UNKNOWN 2023-06-12 18:17:00 -03:00
builtin-evlist.c perf util: Move input_name to util 2023-04-10 19:21:31 -03:00
builtin-ftrace.c perf tools fixes for v6.4: 2nd batch 2023-05-31 15:31:56 -03:00
builtin-help.c perf path: Make mkpath thread safe, remove 16384 bytes from .bss 2023-05-28 10:24:14 -03:00
builtin-inject.c perf inject: Lazily allocate guest_event event_buf 2023-06-12 18:18:14 -03:00
builtin-kallsyms.c perf symbol: Remove now unused symbol_conf.sort_by_name 2023-06-23 21:48:49 -07:00
builtin-kmem.c perf callchain: Use pthread keys for tls callchain_cursor 2023-06-12 15:57:54 -03:00
builtin-kvm.c perf evsel: Introduce evsel__name_is() method to check if the evsel name is equal to a given string 2023-04-24 14:28:11 -03:00
builtin-kwork.c perf callchain: Use pthread keys for tls callchain_cursor 2023-06-12 15:57:54 -03:00
builtin-list.c perf list: Check arguments to show libpfm4 events 2023-06-12 15:57:53 -03:00
builtin-lock.c perf lock contention: Add --output option 2023-07-01 10:48:48 -07:00
builtin-mem.c perf addr_location: Add init/exit/copy functions 2023-06-12 15:57:53 -03:00
builtin-probe.c perf probe: Dynamically allocate params memory 2023-05-28 10:24:02 -03:00
builtin-record.c perf pmus: Remove perf_pmus__has_hybrid 2023-05-27 09:42:38 -03:00
builtin-report.c perf symbol: Remove now unused symbol_conf.sort_by_name 2023-06-23 21:48:49 -07:00
builtin-sched.c perf sched: Avoid large stack allocations 2023-06-12 18:18:14 -03:00
builtin-script.c perf script: Remove some large stack allocations 2023-06-12 18:18:14 -03:00
builtin-stat.c perf stat: Add missing newline in pr_err messages 2023-06-20 15:55:13 -07:00
builtin-timechart.c perf addr_location: Add init/exit/copy functions 2023-06-12 15:57:53 -03:00
builtin-top.c perf annotation: Switch lock from a mutex to a sharded_mutex 2023-06-20 17:04:21 -07:00
builtin-trace.c perf callchain: Use pthread keys for tls callchain_cursor 2023-06-12 15:57:54 -03:00
builtin-version.c Revert "perf build: Make BUILD_BPF_SKEL default, rename to NO_BPF_SKEL" 2023-05-06 18:07:37 -03:00
builtin.h perf usage: Move usage strings 2023-04-10 19:20:53 -03:00
check-headers.sh tools headers: Make the difference output easier to read 2023-06-09 10:56:40 -03:00
command-list.txt perf help: Use HAVE_LIBTRACEEVENT to filter out unsupported commands 2023-01-02 11:51:53 -03:00
CREDITS
design.txt
Makefile perf tools: Use "grep -E" instead of "egrep" 2022-12-14 15:28:19 -03:00
Makefile.config perf build: Fix library not found error when using CSLIBS 2023-07-11 11:46:35 -03:00
Makefile.perf perf: Replace deprecated -target with --target= for Clang 2023-06-27 12:13:22 -07:00
MANIFEST tools lib traceevent: Remove libtraceevent 2022-12-14 11:16:12 -03:00
perf-archive.sh
perf-completion.sh perf tools: Fix auto-complete on aarch64 2023-02-08 10:38:10 -03:00
perf-iostat.sh
perf-read-vdso.c
perf-sys.h
perf.c perf util: Move input_name to util 2023-04-10 19:21:31 -03:00
perf.h perf util: Move perf_guest/host declarations 2023-04-10 19:22:05 -03:00