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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-02-10 17:02:23 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-02-10 17:02:23 -0800 |
| commit | f1c538ca8100776c089b4a682202bea1332a8cb3 (patch) | |
| tree | 4cc1fe3a2b8e94bbb597723307e06041de7722ea /tools | |
| parent | 353a7e8a69058591c3ec40028063af798b698559 (diff) | |
| parent | 546e9289c74f606423ef72075b34cc38eda3bb49 (diff) | |
| download | linux-next-f1c538ca8100776c089b4a682202bea1332a8cb3.tar.gz linux-next-f1c538ca8100776c089b4a682202bea1332a8cb3.zip | |
Merge tag 'timers-vdso-2026-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull VDSO updates from Thomas Gleixner:
- Provide the missing 64-bit variant of clock_getres()
This allows the extension of CONFIG_COMPAT_32BIT_TIME to the vDSO and
finally the removal of 32-bit time types from the kernel and UAPI.
- Remove the useless and broken getcpu_cache from the VDSO
The intention was to provide a trivial way to retrieve the CPU number
from the VDSO, but as the VDSO data is per process there is no way to
make it work.
- Switch get/put_unaligned() from packed struct to memcpy()
The packed struct violates strict aliasing rules which requires to
pass -fno-strict-aliasing to the compiler. As this are scalar values
__builtin_memcpy() turns them into simple loads and stores
- Use __typeof_unqual__() for __unqual_scalar_typeof()
The get/put_unaligned() changes triggered a new sparse warning when
__beNN types are used with get/put_unaligned() as sparse builds add a
special 'bitwise' attribute to them which prevents sparse to evaluate
the Generic in __unqual_scalar_typeof().
Newer sparse versions support __typeof_unqual__() which avoids the
problem, but requires a recent sparse install. So this adds a sanity
check to sparse builds, which validates that sparse is available and
capable of handling it.
- Force inline __cvdso_clock_getres_common()
Compilers sometimes un-inline agressively, which results in function
call overhead and problems with automatic stack variable
initialization.
Interestingly enough the force inlining results in smaller code than
the un-inlined variant produced by GCC when optimizing for size.
* tag 'timers-vdso-2026-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
vdso/gettimeofday: Force inlining of __cvdso_clock_getres_common()
x86/percpu: Make CONFIG_USE_X86_SEG_SUPPORT work with sparse
compiler: Use __typeof_unqual__() for __unqual_scalar_typeof()
powerpc/vdso: Provide clock_getres_time64()
tools headers: Remove unneeded ignoring of warnings in unaligned.h
tools headers: Update the linux/unaligned.h copy with the kernel sources
vdso: Switch get/put_unaligned() from packed struct to memcpy()
parisc: Inline a type punning version of get_unaligned_le32()
vdso: Remove struct getcpu_cache
MIPS: vdso: Provide getres_time64() for 32-bit ABIs
arm64: vdso32: Provide clock_getres_time64()
ARM: VDSO: Provide clock_getres_time64()
ARM: VDSO: Patch out __vdso_clock_getres() if unavailable
x86/vdso: Provide clock_getres_time64() for x86-32
selftests: vDSO: vdso_test_abi: Add test for clock_getres_time64()
selftests: vDSO: vdso_test_abi: Use UAPI system call numbers
selftests: vDSO: vdso_config: Add configurations for clock_getres_time64()
vdso: Add prototype for __vdso_clock_getres_time64()
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/include/linux/compiler_types.h | 22 | ||||
| -rw-r--r-- | tools/include/linux/unaligned.h | 4 | ||||
| -rw-r--r-- | tools/include/vdso/unaligned.h | 41 | ||||
| -rw-r--r-- | tools/testing/selftests/vDSO/vdso_config.h | 4 | ||||
| -rw-r--r-- | tools/testing/selftests/vDSO/vdso_test_abi.c | 55 | ||||
| -rw-r--r-- | tools/testing/selftests/vDSO/vdso_test_getcpu.c | 4 |
6 files changed, 114 insertions, 16 deletions
diff --git a/tools/include/linux/compiler_types.h b/tools/include/linux/compiler_types.h index 14e420467eee..b3adbf5682f0 100644 --- a/tools/include/linux/compiler_types.h +++ b/tools/include/linux/compiler_types.h @@ -24,4 +24,26 @@ #define asm_goto_output(x...) asm goto(x) #endif +/* + * __unqual_scalar_typeof(x) - Declare an unqualified scalar type, leaving + * non-scalar types unchanged. + */ +/* + * Prefer C11 _Generic for better compile-times and simpler code. Note: 'char' + * is not type-compatible with 'signed char', and we define a separate case. + */ +#define __scalar_type_to_expr_cases(type) \ + unsigned type: (unsigned type)0, \ + signed type: (signed type)0 + +#define __unqual_scalar_typeof(x) typeof( \ + _Generic((x), \ + char: (char)0, \ + __scalar_type_to_expr_cases(char), \ + __scalar_type_to_expr_cases(short), \ + __scalar_type_to_expr_cases(int), \ + __scalar_type_to_expr_cases(long), \ + __scalar_type_to_expr_cases(long long), \ + default: (x))) + #endif /* __LINUX_COMPILER_TYPES_H */ diff --git a/tools/include/linux/unaligned.h b/tools/include/linux/unaligned.h index 395a4464fe73..d51ddafed138 100644 --- a/tools/include/linux/unaligned.h +++ b/tools/include/linux/unaligned.h @@ -6,9 +6,6 @@ * This is the most generic implementation of unaligned accesses * and should work almost anywhere. */ -#pragma GCC diagnostic push -#pragma GCC diagnostic ignored "-Wpacked" -#pragma GCC diagnostic ignored "-Wattributes" #include <vdso/unaligned.h> #define get_unaligned(ptr) __get_unaligned_t(typeof(*(ptr)), (ptr)) @@ -143,6 +140,5 @@ static inline u64 get_unaligned_be48(const void *p) { return __get_unaligned_be48(p); } -#pragma GCC diagnostic pop #endif /* __LINUX_UNALIGNED_H */ diff --git a/tools/include/vdso/unaligned.h b/tools/include/vdso/unaligned.h index ff0c06b6513e..9076483c9fbb 100644 --- a/tools/include/vdso/unaligned.h +++ b/tools/include/vdso/unaligned.h @@ -2,14 +2,43 @@ #ifndef __VDSO_UNALIGNED_H #define __VDSO_UNALIGNED_H -#define __get_unaligned_t(type, ptr) ({ \ - const struct { type x; } __packed * __get_pptr = (typeof(__get_pptr))(ptr); \ - __get_pptr->x; \ +#include <linux/compiler_types.h> + +/** + * __get_unaligned_t - read an unaligned value from memory. + * @type: the type to load from the pointer. + * @ptr: the pointer to load from. + * + * Use memcpy to affect an unaligned type sized load avoiding undefined behavior + * from approaches like type punning that require -fno-strict-aliasing in order + * to be correct. As type may be const, use __unqual_scalar_typeof to map to a + * non-const type - you can't memcpy into a const type. The + * __get_unaligned_ctrl_type gives __unqual_scalar_typeof its required + * expression rather than type, a pointer is used to avoid warnings about mixing + * the use of 0 and NULL. The void* cast silences ubsan warnings. + */ +#define __get_unaligned_t(type, ptr) ({ \ + type *__get_unaligned_ctrl_type __always_unused = NULL; \ + __unqual_scalar_typeof(*__get_unaligned_ctrl_type) __get_unaligned_val; \ + __builtin_memcpy(&__get_unaligned_val, (void *)(ptr), \ + sizeof(__get_unaligned_val)); \ + __get_unaligned_val; \ }) -#define __put_unaligned_t(type, val, ptr) do { \ - struct { type x; } __packed * __put_pptr = (typeof(__put_pptr))(ptr); \ - __put_pptr->x = (val); \ +/** + * __put_unaligned_t - write an unaligned value to memory. + * @type: the type of the value to store. + * @val: the value to store. + * @ptr: the pointer to store to. + * + * Use memcpy to affect an unaligned type sized store avoiding undefined + * behavior from approaches like type punning that require -fno-strict-aliasing + * in order to be correct. The void* cast silences ubsan warnings. + */ +#define __put_unaligned_t(type, val, ptr) do { \ + type __put_unaligned_val = (val); \ + __builtin_memcpy((void *)(ptr), &__put_unaligned_val, \ + sizeof(__put_unaligned_val)); \ } while (0) #endif /* __VDSO_UNALIGNED_H */ diff --git a/tools/testing/selftests/vDSO/vdso_config.h b/tools/testing/selftests/vDSO/vdso_config.h index 50c261005111..5da223731b81 100644 --- a/tools/testing/selftests/vDSO/vdso_config.h +++ b/tools/testing/selftests/vDSO/vdso_config.h @@ -66,7 +66,7 @@ static const char *versions[7] = { }; __attribute__((unused)) -static const char *names[2][7] = { +static const char *names[2][8] = { { "__kernel_gettimeofday", "__kernel_clock_gettime", @@ -75,6 +75,7 @@ static const char *names[2][7] = { "__kernel_getcpu", "__kernel_clock_gettime64", "__kernel_getrandom", + "__kernel_clock_getres_time64", }, { "__vdso_gettimeofday", @@ -84,6 +85,7 @@ static const char *names[2][7] = { "__vdso_getcpu", "__vdso_clock_gettime64", "__vdso_getrandom", + "__vdso_clock_getres_time64", }, }; diff --git a/tools/testing/selftests/vDSO/vdso_test_abi.c b/tools/testing/selftests/vDSO/vdso_test_abi.c index c620317eaeea..b162a4ba9c4f 100644 --- a/tools/testing/selftests/vDSO/vdso_test_abi.c +++ b/tools/testing/selftests/vDSO/vdso_test_abi.c @@ -36,6 +36,7 @@ typedef long (*vdso_gettimeofday_t)(struct timeval *tv, struct timezone *tz); typedef long (*vdso_clock_gettime_t)(clockid_t clk_id, struct timespec *ts); typedef long (*vdso_clock_gettime64_t)(clockid_t clk_id, struct vdso_timespec64 *ts); typedef long (*vdso_clock_getres_t)(clockid_t clk_id, struct timespec *ts); +typedef long (*vdso_clock_getres_time64_t)(clockid_t clk_id, struct vdso_timespec64 *ts); typedef time_t (*vdso_time_t)(time_t *t); static const char * const vdso_clock_name[] = { @@ -179,7 +180,7 @@ static void vdso_test_clock_getres(clockid_t clk_id) clock_getres_fail++; } - ret = syscall(SYS_clock_getres, clk_id, &sys_ts); + ret = syscall(__NR_clock_getres, clk_id, &sys_ts); ksft_print_msg("The syscall resolution is %lld %lld\n", (long long)sys_ts.tv_sec, (long long)sys_ts.tv_nsec); @@ -196,6 +197,55 @@ static void vdso_test_clock_getres(clockid_t clk_id) } } +#ifdef __NR_clock_getres_time64 +static void vdso_test_clock_getres_time64(clockid_t clk_id) +{ + int clock_getres_fail = 0; + + /* Find clock_getres. */ + vdso_clock_getres_time64_t vdso_clock_getres_time64 = + (vdso_clock_getres_time64_t)vdso_sym(version, name[7]); + + if (!vdso_clock_getres_time64) { + ksft_print_msg("Couldn't find %s\n", name[7]); + ksft_test_result_skip("%s %s\n", name[7], + vdso_clock_name[clk_id]); + return; + } + + struct vdso_timespec64 ts, sys_ts; + long ret = VDSO_CALL(vdso_clock_getres_time64, 2, clk_id, &ts); + + if (ret == 0) { + ksft_print_msg("The vdso resolution is %lld %lld\n", + (long long)ts.tv_sec, (long long)ts.tv_nsec); + } else { + clock_getres_fail++; + } + + ret = syscall(__NR_clock_getres_time64, clk_id, &sys_ts); + + ksft_print_msg("The syscall resolution is %lld %lld\n", + (long long)sys_ts.tv_sec, (long long)sys_ts.tv_nsec); + + if ((sys_ts.tv_sec != ts.tv_sec) || (sys_ts.tv_nsec != ts.tv_nsec)) + clock_getres_fail++; + + if (clock_getres_fail > 0) { + ksft_test_result_fail("%s %s\n", name[7], + vdso_clock_name[clk_id]); + } else { + ksft_test_result_pass("%s %s\n", name[7], + vdso_clock_name[clk_id]); + } +} +#else /* !__NR_clock_getres_time64 */ +static void vdso_test_clock_getres_time64(clockid_t clk_id) +{ + ksft_test_result_skip("%s %s\n", name[7], vdso_clock_name[clk_id]); +} +#endif /* __NR_clock_getres_time64 */ + /* * This function calls vdso_test_clock_gettime and vdso_test_clock_getres * with different values for clock_id. @@ -208,9 +258,10 @@ static inline void vdso_test_clock(clockid_t clock_id) vdso_test_clock_gettime64(clock_id); vdso_test_clock_getres(clock_id); + vdso_test_clock_getres_time64(clock_id); } -#define VDSO_TEST_PLAN 29 +#define VDSO_TEST_PLAN 38 int main(int argc, char **argv) { diff --git a/tools/testing/selftests/vDSO/vdso_test_getcpu.c b/tools/testing/selftests/vDSO/vdso_test_getcpu.c index bea8ad54da11..3fe49cbdae98 100644 --- a/tools/testing/selftests/vDSO/vdso_test_getcpu.c +++ b/tools/testing/selftests/vDSO/vdso_test_getcpu.c @@ -16,9 +16,7 @@ #include "vdso_config.h" #include "vdso_call.h" -struct getcpu_cache; -typedef long (*getcpu_t)(unsigned int *, unsigned int *, - struct getcpu_cache *); +typedef long (*getcpu_t)(unsigned int *, unsigned int *, void *); int main(int argc, char **argv) { |
