diff options
| author | Kees Cook <kees+treewide@kernel.org> | 2026-09-02 15:31:14 -0700 |
|---|---|---|
| committer | Kees Cook <kees@kernel.org> | 2026-09-04 21:37:00 -0700 |
| commit | 3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d (patch) | |
| tree | c65086f9bdcd48c6360fb7cb4598bca084da1f32 /tools/lib/perf/TODO | |
| download | linux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.tar.gz linux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.zip | |
treewide: refresh kmalloc_obj() conversionsgrafted
This is another run of the Coccinelle script for converting kmalloc()
family of allocations to kmalloc_obj() via the existing rules in
scripts/coccinelle/api/kmalloc_objs.cocci
This catches both the set of kmalloc() uses added since the first
kmalloc_obj() conversions in v7.0 and adds a large group missed in the
first pass due to Coccinelle not interacting well with the cleanup.h
scoped_...() family of macros[1]. I worked around this with spatch's
"--macro-file" argument to a file with all the scoped_...() macros mapped
to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control
flow indicator I could find.
Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc,
riscv, and s390 with no new warnings.
Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1]
Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2]
Signed-off-by: Kees Cook <kees+treewide@kernel.org>
Diffstat (limited to 'tools/lib/perf/TODO')
| -rw-r--r-- | tools/lib/perf/TODO | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/tools/lib/perf/TODO b/tools/lib/perf/TODO new file mode 100644 index 000000000..e17972869 --- /dev/null +++ b/tools/lib/perf/TODO @@ -0,0 +1,30 @@ +Future ABI changes +================== + +This file collects items that require a libperf ABI bump. Each entry +should describe the current limitation, the desired end state, and the +scope of the change so that a future ABI revision can batch them +together. + +1. Widen struct perf_cpu.cpu from int16_t to int + - Current limit: 32767 CPUs. No architecture exceeds this today + (x86_64 max is 8192, arm64 is 4096), but NR_CPUS limits keep + growing. perf clamps to INT16_MAX in set_max_cpu_num() as a + safety net. + - Code simplification: the int16_t forces defensive truncation + checks at every boundary where a wider CPU index (int from + sample->cpu, al->cpu, etc.) is narrowed into struct perf_cpu. + Without these checks, values > 32767 silently wrap to negative + numbers (two's complement), bypassing bounds validation. + Widening to int eliminates this entire class of silent + truncation bugs and removes the need for the INT16_MAX clamp + in set_max_cpu_num(). + - Scope: struct perf_cpu is embedded everywhere — perf_cpu_map__cpu(), + perf_cpu_map__min(), perf_cpu_map__max(), perf_cpu_map__has(), the + for_each_cpu macros, and all internal callers. The perf_cpu_map + internal array (RC_CHK_ACCESS(map)->map[]) stores struct perf_cpu + directly. Widening changes the struct layout and every function + that returns or accepts struct perf_cpu by value. + - Migration: bump LIBPERF version in libperf.map, audit all + sizeof(struct perf_cpu) assumptions, update perf.data + serialization if needed. |
