From 7158fc54b2c6f124eec0d7cd13bff69da0172e59 Mon Sep 17 00:00:00 2001 From: Thomas Weißschuh Date: Tue, 30 Dec 2025 08:08:44 +0100 Subject: vdso: Remove struct getcpu_cache MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The cache parameter of getcpu() is useless nowadays for various reasons. * It is never passed by userspace for either the vDSO or syscalls. * It is never used by the kernel. * It could not be made to work on the current vDSO architecture. * The structure definition is not part of the UAPI headers. * vdso_getcpu() is superseded by restartable sequences in any case. Remove the struct and its header. As a side-effect this gets rid of an unwanted inclusion of the linux/ header namespace from vDSO code. [ tglx: Adapt to s390 upstream changes */ Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Acked-by: Arnd Bergmann Acked-by: Heiko Carstens # s390 Link: https://patch.msgid.link/20251230-getcpu_cache-v3-1-fb9c5f880ebe@linutronix.de --- include/linux/getcpu.h | 19 ------------------- include/linux/syscalls.h | 3 +-- 2 files changed, 1 insertion(+), 21 deletions(-) delete mode 100644 include/linux/getcpu.h (limited to 'include/linux') diff --git a/include/linux/getcpu.h b/include/linux/getcpu.h deleted file mode 100644 index c304dcdb4eac..000000000000 --- 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 Results might be a short time - out of date, but will be faster.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 cf84d98964b2..23704e006afd 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; @@ -718,7 +717,7 @@ 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, -- cgit v1.2.3 From fd69b2f7d5f4e1d89cea4cdfa6f15e7fa53d8358 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 16 Jan 2026 19:18:16 +0100 Subject: compiler: Use __typeof_unqual__() for __unqual_scalar_typeof() The recent changes to get_unaligned() resulted in a new sparse warning: net/rds/ib_cm.c:96:35: sparse: sparse: incorrect type in argument 1 (different modifiers) @@ expected void * @@ got restricted __be64 const * @@ net/rds/ib_cm.c:96:35: sparse: expected void * net/rds/ib_cm.c:96:35: sparse: got restricted __be64 const * The updated get_unaligned_t() uses __unqual_scalar_typeof() to get an unqualified type. This works correctly for the compilers, but fails for sparse when the data type is __be64 (or any other __beNN variant). On sparse runs (C=[12]) __beNN types are annotated with __attribute__((bitwise)). That annotation allows sparse to detect incompatible operations on __beNN variables, but it also prevents sparse from evaluating the _Generic() in __unqual_scalar_typeof() and map __beNN to a unqualified scalar type, so it ends up with the default, i.e. the original qualified type of a 'const __beNN' pointer. That then ends up as the first pointer argument to builtin_memcpy(), which obviously causes the above sparse warnings. The sparse git tree supports typeof_unqual() now, which allows to use it instead of the _Generic() based __unqual_scalar_typeof(). With that sparse correctly evaluates the unqualified type and keeps the __beNN logic intact. The downside is that this requires a top of tree sparse build and an old sparse version will emit a metric ton of incomprehensible error messages before it dies with a segfault. Therefore implement a sanity check which validates that the checker is available and capable of handling typeof_unqual(). Emit a warning if not so the user can take informed action. [ tglx: Move the evaluation of USE_TYPEOF_UNQUAL to compiler_types.h so it is set before use and implement the sanity checker ] Reported-by: kernel test robot Signed-off-by: Peter Zijlstra Signed-off-by: Thomas Gleixner Acked-by: Ian Rogers Link: https://patch.msgid.link/87ecnp2zh3.ffs@tglx Closes: https://lore.kernel.org/oe-kbuild-all/202601150001.sKSN644a-lkp@intel.com/ --- Makefile | 8 ++++++++ include/linux/compiler.h | 10 ---------- include/linux/compiler_types.h | 13 +++++++++++++ scripts/checker-valid.sh | 19 +++++++++++++++++++ 4 files changed, 40 insertions(+), 10 deletions(-) create mode 100755 scripts/checker-valid.sh (limited to 'include/linux') diff --git a/Makefile b/Makefile index 9d38125263fb..179c9d9a56dd 100644 --- a/Makefile +++ b/Makefile @@ -1187,6 +1187,14 @@ CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian) # the checker needs the correct machine size CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32) +# Validate the checker is available and functional +ifneq ($(KBUILD_CHECKSRC), 0) + ifneq ($(shell $(srctree)/scripts/checker-valid.sh $(CHECK) $(CHECKFLAGS)), 1) + $(warning C=$(KBUILD_CHECKSRC) specified, but $(CHECK) is not available or not up to date) + KBUILD_CHECKSRC = 0 + endif +endif + # Default kernel image to build when no specific target is given. # KBUILD_IMAGE may be overruled on the command line or # set in the environment diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 04487c9bd751..c601222b495a 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -230,16 +230,6 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, __BUILD_BUG_ON_ZERO_MSG(!__is_noncstr(p), \ "must be non-C-string (not NUL-terminated)") -/* - * Use __typeof_unqual__() when available. - * - * XXX: Remove test for __CHECKER__ once - * sparse learns about __typeof_unqual__(). - */ -#if CC_HAS_TYPEOF_UNQUAL && !defined(__CHECKER__) -# define USE_TYPEOF_UNQUAL 1 -#endif - /* * Define TYPEOF_UNQUAL() to use __typeof_unqual__() as typeof * operator when available, to return an unqualified type of the exp. diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h index d3318a3c2577..377df1e64096 100644 --- a/include/linux/compiler_types.h +++ b/include/linux/compiler_types.h @@ -562,6 +562,14 @@ struct ftrace_likely_data { #define asm_inline asm #endif +#ifndef __ASSEMBLY__ +/* + * Use __typeof_unqual__() when available. + */ +#if CC_HAS_TYPEOF_UNQUAL || defined(__CHECKER__) +# define USE_TYPEOF_UNQUAL 1 +#endif + /* Are two types/vars the same type (ignoring qualifiers)? */ #define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b)) @@ -569,6 +577,7 @@ struct ftrace_likely_data { * __unqual_scalar_typeof(x) - Declare an unqualified scalar type, leaving * non-scalar types unchanged. */ +#ifndef USE_TYPEOF_UNQUAL /* * 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. @@ -586,6 +595,10 @@ struct ftrace_likely_data { __scalar_type_to_expr_cases(long), \ __scalar_type_to_expr_cases(long long), \ default: (x))) +#else +#define __unqual_scalar_typeof(x) __typeof_unqual__(x) +#endif +#endif /* !__ASSEMBLY__ */ /* Is this type a native word size -- useful for atomic operations */ #define __native_word(t) \ diff --git a/scripts/checker-valid.sh b/scripts/checker-valid.sh new file mode 100755 index 000000000000..625a789ed1c8 --- /dev/null +++ b/scripts/checker-valid.sh @@ -0,0 +1,19 @@ +#!/bin/sh -eu +# SPDX-License-Identifier: GPL-2.0 + +[ ! -x "$(command -v "$1")" ] && exit 1 + +tmp_file=$(mktemp) +trap "rm -f $tmp_file" EXIT + +cat << EOF >$tmp_file +static inline int u(const int *q) +{ + __typeof_unqual__(*q) v = *q; + return v; +} +EOF + +# sparse happily exits with 0 on error so validate +# there is none on stderr. Use awk as grep is a pain with sh -e +$@ $tmp_file 2>&1 | awk -v c=1 '/error/{c=0}END{print c}' -- cgit v1.2.3