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authorLinus Torvalds <torvalds@linux-foundation.org>2026-02-10 17:02:23 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2026-02-10 17:02:23 -0800
commitf1c538ca8100776c089b4a682202bea1332a8cb3 (patch)
tree4cc1fe3a2b8e94bbb597723307e06041de7722ea /tools
parent353a7e8a69058591c3ec40028063af798b698559 (diff)
parent546e9289c74f606423ef72075b34cc38eda3bb49 (diff)
downloadlinux-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.h22
-rw-r--r--tools/include/linux/unaligned.h4
-rw-r--r--tools/include/vdso/unaligned.h41
-rw-r--r--tools/testing/selftests/vDSO/vdso_config.h4
-rw-r--r--tools/testing/selftests/vDSO/vdso_test_abi.c55
-rw-r--r--tools/testing/selftests/vDSO/vdso_test_getcpu.c4
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)
{