mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2026-08-09 06:14:34 +02:00
Nathan Chancellor
175db11786
Clang recently added support for -Wattribute-alias [1], which results in
the same warnings that necessitated commit bee2003177 ("disable
-Wattribute-alias warning for SYSCALL_DEFINEx()") for GCC.
kernel/time/itimer.c:325:1: error: alias and aliasee have different types 'long (unsigned int)' and 'long (typeof (__builtin_choose_expr((__builtin_types_compatible_p(typeof ((unsigned int)0), typeof (0LL)) || __builtin_types_compatible_p(typeof ((unsigned int)0), typeof (0ULL))), 0LL, 0L)))' (aka 'long (long)') [-Werror,-Wattribute-alias]
325 | SYSCALL_DEFINE1(alarm, unsigned int, seconds)
| ^
include/linux/syscalls.h:225:36: note: expanded from macro 'SYSCALL_DEFINE1'
225 | #define SYSCALL_DEFINE1(name, ...) SYSCALL_DEFINEx(1, _##name, __VA_ARGS__)
| ^
include/linux/syscalls.h:236:2: note: expanded from macro 'SYSCALL_DEFINEx'
236 | __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
| ^
include/linux/syscalls.h:251:18: note: expanded from macro '__SYSCALL_DEFINEx'
251 | __attribute__((alias(__stringify(__se_sys##name)))); \
| ^
kernel/time/itimer.c:325:1: note: aliasee is declared here
include/linux/syscalls.h:225:36: note: expanded from macro 'SYSCALL_DEFINE1'
225 | #define SYSCALL_DEFINE1(name, ...) SYSCALL_DEFINEx(1, _##name, __VA_ARGS__)
| ^
include/linux/syscalls.h:236:2: note: expanded from macro 'SYSCALL_DEFINEx'
236 | __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
| ^
include/linux/syscalls.h:255:18: note: expanded from macro '__SYSCALL_DEFINEx'
255 | asmlinkage long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \
| ^
<scratch space>:16:1: note: expanded from here
16 | __se_sys_alarm
| ^
Disable the warnings in the same way for clang-23 and newer. Disable the
warning about unknown warning options to avoid breaking the build for
versions of clang-23 that do not have -Wattribute-alias, such as ones
deployed by vendors like Android or CI systems or when bisecting LLVM
between llvmorg-23-init and release/23.x.
Cc: stable@vger.kernel.org
Closes: https://github.com/ClangBuiltLinux/linux/issues/2163
Link: https://github.com/llvm/llvm-project/commit/40da6920a0d71d49dfa2392b09153600b0759f5e [1]
Link: https://patch.msgid.link/20260515-syscall-disable-attribute-alias-for-clang-v1-1-9a9d95d41df6@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
113 lines
4.2 KiB
C
113 lines
4.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* syscall_wrapper.h - riscv specific wrappers to syscall definitions
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*
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* Based on arch/arm64/include/syscall_wrapper.h
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*/
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#ifndef __ASM_SYSCALL_WRAPPER_H
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#define __ASM_SYSCALL_WRAPPER_H
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#include <asm/ptrace.h>
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asmlinkage long __riscv_sys_ni_syscall(const struct pt_regs *);
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#ifdef CONFIG_64BIT
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#define __SYSCALL_SE_DEFINEx(x, prefix, name, ...) \
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static long __se_##prefix##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \
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static long __se_##prefix##name(__MAP(x,__SC_LONG,__VA_ARGS__))
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#define SC_RISCV_REGS_TO_ARGS(x, ...) \
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__MAP(x,__SC_ARGS \
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,,regs->orig_a0,,regs->a1,,regs->a2 \
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,,regs->a3,,regs->a4,,regs->a5,,regs->a6)
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#else
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/*
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* Use type aliasing to ensure registers a0-a6 are correctly passed to the syscall
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* implementation when >word-size arguments are used.
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*/
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#define __SYSCALL_SE_DEFINEx(x, prefix, name, ...) \
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__diag_push(); \
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__diag_ignore(GCC, 8, "-Wattribute-alias", \
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"Type aliasing is used to sanitize syscall arguments"); \
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__diag_ignore(clang, 23, "-Wunknown-warning-option", \
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"Avoid breaking versions without -Wattribute-alias"); \
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__diag_ignore(clang, 23, "-Wattribute-alias", \
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"Type aliasing is used to sanitize syscall arguments"); \
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static long __se_##prefix##name(ulong, ulong, ulong, ulong, ulong, ulong, \
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ulong) \
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__attribute__((alias(__stringify(___se_##prefix##name)))); \
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__diag_pop(); \
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static long noinline ___se_##prefix##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \
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__used; \
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static long ___se_##prefix##name(__MAP(x,__SC_LONG,__VA_ARGS__))
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#define SC_RISCV_REGS_TO_ARGS(x, ...) \
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regs->orig_a0,regs->a1,regs->a2,regs->a3,regs->a4,regs->a5,regs->a6
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#endif /* CONFIG_64BIT */
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#ifdef CONFIG_COMPAT
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#define COMPAT_SYSCALL_DEFINEx(x, name, ...) \
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asmlinkage long __riscv_compat_sys##name(const struct pt_regs *regs); \
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ALLOW_ERROR_INJECTION(__riscv_compat_sys##name, ERRNO); \
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static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
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__SYSCALL_SE_DEFINEx(x, compat_sys, name, __VA_ARGS__) \
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{ \
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return __do_compat_sys##name(__MAP(x,__SC_DELOUSE,__VA_ARGS__)); \
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} \
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asmlinkage long __riscv_compat_sys##name(const struct pt_regs *regs) \
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{ \
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return __se_compat_sys##name(SC_RISCV_REGS_TO_ARGS(x,__VA_ARGS__)); \
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} \
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static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))
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#define COMPAT_SYSCALL_DEFINE0(sname) \
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asmlinkage long __riscv_compat_sys_##sname(const struct pt_regs *__unused); \
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ALLOW_ERROR_INJECTION(__riscv_compat_sys_##sname, ERRNO); \
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asmlinkage long __riscv_compat_sys_##sname(const struct pt_regs *__unused)
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#define COND_SYSCALL_COMPAT(name) \
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asmlinkage long __weak __riscv_compat_sys_##name(const struct pt_regs *regs); \
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asmlinkage long __weak __riscv_compat_sys_##name(const struct pt_regs *regs) \
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{ \
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return sys_ni_syscall(); \
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}
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#endif /* CONFIG_COMPAT */
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#define __SYSCALL_DEFINEx(x, name, ...) \
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asmlinkage long __riscv_sys##name(const struct pt_regs *regs); \
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ALLOW_ERROR_INJECTION(__riscv_sys##name, ERRNO); \
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static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
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__SYSCALL_SE_DEFINEx(x, sys, name, __VA_ARGS__) \
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{ \
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long ret = __do_sys##name(__MAP(x,__SC_CAST,__VA_ARGS__)); \
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__MAP(x,__SC_TEST,__VA_ARGS__); \
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__PROTECT(x, ret,__MAP(x,__SC_ARGS,__VA_ARGS__)); \
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return ret; \
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} \
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asmlinkage long __riscv_sys##name(const struct pt_regs *regs) \
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{ \
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return __se_sys##name(SC_RISCV_REGS_TO_ARGS(x,__VA_ARGS__)); \
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} \
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static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))
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#define SYSCALL_DEFINE0(sname) \
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SYSCALL_METADATA(_##sname, 0); \
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asmlinkage long __riscv_sys_##sname(const struct pt_regs *__unused); \
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ALLOW_ERROR_INJECTION(__riscv_sys_##sname, ERRNO); \
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asmlinkage long __riscv_sys_##sname(const struct pt_regs *__unused)
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#define COND_SYSCALL(name) \
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asmlinkage long __weak __riscv_sys_##name(const struct pt_regs *regs); \
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asmlinkage long __weak __riscv_sys_##name(const struct pt_regs *regs) \
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{ \
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return sys_ni_syscall(); \
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}
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#endif /* __ASM_SYSCALL_WRAPPER_H */
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