The cache parameter of getcpu() is not used by the kernel and no user ever passes it in anyways.
Remove the struct and its header.
As a side-effect we get rid of an unwanted inclusion of the linux/ header namespace from vDSO code.
Signed-off-by: Thomas Weißschuh thomas.weissschuh@linutronix.de --- Changes in v2: - Rebase on v6.18-rc1 - Link to v1: https://lore.kernel.org/r/20250826-getcpu_cache-v1-1-8748318f6141@linutronix... --- We could also completely remove the parameter, but I am not sure if that is a good idea for syscalls and vDSO entrypoints. --- arch/loongarch/vdso/vgetcpu.c | 5 ++--- arch/s390/kernel/vdso64/getcpu.c | 3 +-- arch/s390/kernel/vdso64/vdso.h | 4 +--- arch/x86/entry/vdso/vgetcpu.c | 5 ++--- arch/x86/include/asm/vdso/processor.h | 4 +--- arch/x86/um/vdso/um_vdso.c | 7 +++---- include/linux/getcpu.h | 19 ------------------- include/linux/syscalls.h | 3 +-- kernel/sys.c | 4 +--- tools/testing/selftests/vDSO/vdso_test_getcpu.c | 4 +--- 10 files changed, 13 insertions(+), 45 deletions(-)
diff --git a/arch/loongarch/vdso/vgetcpu.c b/arch/loongarch/vdso/vgetcpu.c index 5301cd9d0f839eb0fd7b73a1d36e80aaa75d5e76..aefba899873ed035d70766a95b0b6fea881e94df 100644 --- a/arch/loongarch/vdso/vgetcpu.c +++ b/arch/loongarch/vdso/vgetcpu.c @@ -4,7 +4,6 @@ */
#include <asm/vdso.h> -#include <linux/getcpu.h>
static __always_inline int read_cpu_id(void) { @@ -20,8 +19,8 @@ static __always_inline int read_cpu_id(void) }
extern -int __vdso_getcpu(unsigned int *cpu, unsigned int *node, struct getcpu_cache *unused); -int __vdso_getcpu(unsigned int *cpu, unsigned int *node, struct getcpu_cache *unused) +int __vdso_getcpu(unsigned int *cpu, unsigned int *node, void *unused); +int __vdso_getcpu(unsigned int *cpu, unsigned int *node, void *unused) { int cpu_id;
diff --git a/arch/s390/kernel/vdso64/getcpu.c b/arch/s390/kernel/vdso64/getcpu.c index 5c5d4a848b7669436e73df8e3b711e5b876eb3db..1e17665616c5fa766ca66c8de276b212528934bd 100644 --- a/arch/s390/kernel/vdso64/getcpu.c +++ b/arch/s390/kernel/vdso64/getcpu.c @@ -2,11 +2,10 @@ /* Copyright IBM Corp. 2020 */
#include <linux/compiler.h> -#include <linux/getcpu.h> #include <asm/timex.h> #include "vdso.h"
-int __s390_vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused) +int __s390_vdso_getcpu(unsigned *cpu, unsigned *node, void *unused) { union tod_clock clk;
diff --git a/arch/s390/kernel/vdso64/vdso.h b/arch/s390/kernel/vdso64/vdso.h index 9e5397e7b590a23c149ccc6043d0c0b0d5ea8457..cadd307d7a365cabf53f5c8d313be3718625533d 100644 --- a/arch/s390/kernel/vdso64/vdso.h +++ b/arch/s390/kernel/vdso64/vdso.h @@ -4,9 +4,7 @@
#include <vdso/datapage.h>
-struct getcpu_cache; - -int __s390_vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused); +int __s390_vdso_getcpu(unsigned *cpu, unsigned *node, void *unused); int __s390_vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz); int __s390_vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts); int __s390_vdso_clock_getres(clockid_t clock, struct __kernel_timespec *ts); diff --git a/arch/x86/entry/vdso/vgetcpu.c b/arch/x86/entry/vdso/vgetcpu.c index e4640306b2e3c95d74d73037ab6b09294b8e1d6c..6381b472b7c52487bccf3cbf0664c3d7a0e59699 100644 --- a/arch/x86/entry/vdso/vgetcpu.c +++ b/arch/x86/entry/vdso/vgetcpu.c @@ -6,17 +6,16 @@ */
#include <linux/kernel.h> -#include <linux/getcpu.h> #include <asm/segment.h> #include <vdso/processor.h>
notrace long -__vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused) +__vdso_getcpu(unsigned *cpu, unsigned *node, void *unused) { vdso_read_cpunode(cpu, node);
return 0; }
-long getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *tcache) +long getcpu(unsigned *cpu, unsigned *node, void *tcache) __attribute__((weak, alias("__vdso_getcpu"))); diff --git a/arch/x86/include/asm/vdso/processor.h b/arch/x86/include/asm/vdso/processor.h index 7000aeb59aa287e2119c3d43ab3eaf82befb59c4..93e0e24e5cb47f7b0056c13f2a7f2304ed4a0595 100644 --- a/arch/x86/include/asm/vdso/processor.h +++ b/arch/x86/include/asm/vdso/processor.h @@ -18,9 +18,7 @@ static __always_inline void cpu_relax(void) native_pause(); }
-struct getcpu_cache; - -notrace long __vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused); +notrace long __vdso_getcpu(unsigned *cpu, unsigned *node, void *unused);
#endif /* __ASSEMBLER__ */
diff --git a/arch/x86/um/vdso/um_vdso.c b/arch/x86/um/vdso/um_vdso.c index cbae2584124fd0ff0f9d240c33fefb8d213c84cd..9aa2c62cce6b7a07bbaf8441014d347162d1950d 100644 --- a/arch/x86/um/vdso/um_vdso.c +++ b/arch/x86/um/vdso/um_vdso.c @@ -10,14 +10,13 @@ #define DISABLE_BRANCH_PROFILING
#include <linux/time.h> -#include <linux/getcpu.h> #include <asm/unistd.h>
/* workaround for -Wmissing-prototypes warnings */ int __vdso_clock_gettime(clockid_t clock, struct __kernel_old_timespec *ts); int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz); __kernel_old_time_t __vdso_time(__kernel_old_time_t *t); -long __vdso_getcpu(unsigned int *cpu, unsigned int *node, struct getcpu_cache *unused); +long __vdso_getcpu(unsigned int *cpu, unsigned int *node, void *unused);
int __vdso_clock_gettime(clockid_t clock, struct __kernel_old_timespec *ts) { @@ -60,7 +59,7 @@ __kernel_old_time_t __vdso_time(__kernel_old_time_t *t) __kernel_old_time_t time(__kernel_old_time_t *t) __attribute__((weak, alias("__vdso_time")));
long -__vdso_getcpu(unsigned int *cpu, unsigned int *node, struct getcpu_cache *unused) +__vdso_getcpu(unsigned int *cpu, unsigned int *node, void *unused) { /* * UML does not support SMP, we can cheat here. :) @@ -74,5 +73,5 @@ __vdso_getcpu(unsigned int *cpu, unsigned int *node, struct getcpu_cache *unused return 0; }
-long getcpu(unsigned int *cpu, unsigned int *node, struct getcpu_cache *tcache) +long getcpu(unsigned int *cpu, unsigned int *node, void *tcache) __attribute__((weak, alias("__vdso_getcpu"))); diff --git a/include/linux/getcpu.h b/include/linux/getcpu.h deleted file mode 100644 index c304dcdb4eac2a9117080e6a14f4e3f28d07fd56..0000000000000000000000000000000000000000 --- a/include/linux/getcpu.h +++ /dev/null @@ -1,19 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#ifndef _LINUX_GETCPU_H -#define _LINUX_GETCPU_H 1 - -/* Cache for getcpu() to speed it up. Results might be a short time - out of date, but will be faster. - - User programs should not refer to the contents of this structure. - I repeat they should not refer to it. If they do they will break - in future kernels. - - It is only a private cache for vgetcpu(). It will change in future kernels. - The user program must store this information per thread (__thread) - If you want 100% accurate information pass NULL instead. */ -struct getcpu_cache { - unsigned long blob[128 / sizeof(long)]; -}; - -#endif diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 66c06fcdfe19e27b99eb9a187c22e022e260802f..403488e5eba906ecf40975fc3cb29ed0402491f2 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -59,7 +59,6 @@ struct compat_stat; struct old_timeval32; struct robust_list_head; struct futex_waitv; -struct getcpu_cache; struct old_linux_dirent; struct perf_event_attr; struct file_handle; @@ -714,7 +713,7 @@ asmlinkage long sys_getrusage(int who, struct rusage __user *ru); asmlinkage long sys_umask(int mask); asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, unsigned long arg5); -asmlinkage long sys_getcpu(unsigned __user *cpu, unsigned __user *node, struct getcpu_cache __user *cache); +asmlinkage long sys_getcpu(unsigned __user *cpu, unsigned __user *node, void __user *cache); asmlinkage long sys_gettimeofday(struct __kernel_old_timeval __user *tv, struct timezone __user *tz); asmlinkage long sys_settimeofday(struct __kernel_old_timeval __user *tv, diff --git a/kernel/sys.c b/kernel/sys.c index 8b58eece4e580b883d19bb1336aff627ae783a4d..f1780ab132a3fbce6aac937ade5b9a35d9837f13 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -31,7 +31,6 @@ #include <linux/tty.h> #include <linux/signal.h> #include <linux/cn_proc.h> -#include <linux/getcpu.h> #include <linux/task_io_accounting_ops.h> #include <linux/seccomp.h> #include <linux/cpu.h> @@ -2876,8 +2875,7 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, return error; }
-SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, - struct getcpu_cache __user *, unused) +SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, void __user *, unused) { int err = 0; int cpu = raw_smp_processor_id(); diff --git a/tools/testing/selftests/vDSO/vdso_test_getcpu.c b/tools/testing/selftests/vDSO/vdso_test_getcpu.c index cdeaed45fb26c61f6314c58fe1b71fa0be3c0108..994ce569dc37c6689b1a3c79156e3dfc8bf27f22 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) {
--- base-commit: 3a8660878839faadb4f1a6dd72c3179c1df56787 change-id: 20250825-getcpu_cache-3abcd2e65437
Best regards,