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| 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 /lib/percpu_test.c | |
| 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 'lib/percpu_test.c')
| -rw-r--r-- | lib/percpu_test.c | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/lib/percpu_test.c b/lib/percpu_test.c new file mode 100644 index 000000000..ce7124b16 --- /dev/null +++ b/lib/percpu_test.c @@ -0,0 +1,148 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <linux/limits.h> +#include <linux/module.h> + +/* validate @native and @pcp counter values match @expected */ +#define CHECK(native, pcp, expected) \ + do { \ + WARN((native) != (expected), \ + "raw %ld (0x%lx) != expected %lld (0x%llx)", \ + (native), (native), \ + (long long)(expected), (long long)(expected)); \ + WARN(__this_cpu_read(pcp) != (expected), \ + "pcp %ld (0x%lx) != expected %lld (0x%llx)", \ + __this_cpu_read(pcp), __this_cpu_read(pcp), \ + (long long)(expected), (long long)(expected)); \ + } while (0) + +static DEFINE_PER_CPU(long, long_counter); +static DEFINE_PER_CPU(unsigned long, ulong_counter); + +static int __init percpu_test_init(void) +{ + /* + * volatile prevents compiler from optimizing it uses, otherwise the + * +ul_one/-ul_one below would replace with inc/dec instructions. + */ + volatile unsigned int ui_one = 1; + unsigned long long ull = 0; + unsigned long ul = 0; + long l = 0; + + pr_info("percpu test start\n"); + + preempt_disable(); + + l += -1; + __this_cpu_add(long_counter, -1); + CHECK(l, long_counter, -1); + + l += 1; + __this_cpu_add(long_counter, 1); + CHECK(l, long_counter, 0); + + ul = 0; + __this_cpu_write(ulong_counter, 0); + + ul += 1UL; + __this_cpu_add(ulong_counter, 1UL); + CHECK(ul, ulong_counter, 1); + + ul += -1UL; + __this_cpu_add(ulong_counter, -1UL); + CHECK(ul, ulong_counter, 0); + + ul += -(unsigned long)1; + __this_cpu_add(ulong_counter, -(unsigned long)1); + CHECK(ul, ulong_counter, -1); + + ul = 0; + __this_cpu_write(ulong_counter, 0); + + ul -= 1; + __this_cpu_dec(ulong_counter); + CHECK(ul, ulong_counter, -1); + CHECK(ul, ulong_counter, ULONG_MAX); + + l += -ui_one; + __this_cpu_add(long_counter, -ui_one); + CHECK(l, long_counter, 0xffffffff); + + l += ui_one; + __this_cpu_add(long_counter, ui_one); + CHECK(l, long_counter, (long)0x100000000LL); + + + l = 0; + __this_cpu_write(long_counter, 0); + + l -= ui_one; + __this_cpu_sub(long_counter, ui_one); + CHECK(l, long_counter, -1); + + l = 0; + __this_cpu_write(long_counter, 0); + + l += ui_one; + __this_cpu_add(long_counter, ui_one); + CHECK(l, long_counter, 1); + + l += -ui_one; + __this_cpu_add(long_counter, -ui_one); + CHECK(l, long_counter, (long)0x100000000LL); + + l = 0; + __this_cpu_write(long_counter, 0); + + l -= ui_one; + this_cpu_sub(long_counter, ui_one); + CHECK(l, long_counter, -1); + CHECK(l, long_counter, ULONG_MAX); + + ul = 0; + __this_cpu_write(ulong_counter, 0); + + ul += ui_one; + __this_cpu_add(ulong_counter, ui_one); + CHECK(ul, ulong_counter, 1); + + ul = 0; + __this_cpu_write(ulong_counter, 0); + + ul -= ui_one; + __this_cpu_sub(ulong_counter, ui_one); + CHECK(ul, ulong_counter, -1); + CHECK(ul, ulong_counter, ULONG_MAX); + + ul = ull = 0; + __this_cpu_write(ulong_counter, 0); + + ul = ull += UINT_MAX; + __this_cpu_add(ulong_counter, ull); + CHECK(ul, ulong_counter, UINT_MAX); + + ul = 3; + __this_cpu_write(ulong_counter, 3); + + ul = this_cpu_sub_return(ulong_counter, ui_one); + CHECK(ul, ulong_counter, 2); + + ul = __this_cpu_sub_return(ulong_counter, ui_one); + CHECK(ul, ulong_counter, 1); + + preempt_enable(); + + pr_info("percpu test done\n"); + return -EAGAIN; /* Fail will directly unload the module */ +} + +static void __exit percpu_test_exit(void) +{ +} + +module_init(percpu_test_init) +module_exit(percpu_test_exit) + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Greg Thelen"); +MODULE_DESCRIPTION("percpu operations test"); |
