On Tue, 19 Dec 2023 at 12:17, Linus Torvalds
<torva...@linuxfoundation.org> wrote:
>
> That said, I still think that just getting rid of this horrid special
> case for posix timers is the right thing, and we should just remove
> that SYS_NI() alias thing entirely.
IOW, something like the attached patch.
It's not extensively tested, but hey, the diffstat looks nice:
arch/arm64/include/asm/syscall_wrapper.h | 4 ---
arch/riscv/include/asm/syscall_wrapper.h | 5 ----
arch/s390/include/asm/syscall_wrapper.h | 13 +--------
arch/x86/include/asm/syscall_wrapper.h | 34 +++---------------------
kernel/sys_ni.c | 14 ++++++++++
kernel/time/posix-stubs.c | 45 --------------------------------
6 files changed, 19 insertions(+), 96 deletions(-)
and it builds in at least a *couple* of configurations, including with
CONFIG_POSIX_TIMERS disabled.
I did *not* check whether it might fix the warning, since I doubt my
user space would even boot without that posix timer support (actually,
honestly, because I'm just lazy and "it _looks_ fine to me" was the
main real thing).
But that SYS_NI() thing really does deserve to die, as it was purely
used as a hack for some random timer system calls.
Comments?
Linus
arch/arm64/include/asm/syscall_wrapper.h | 4 ---
arch/riscv/include/asm/syscall_wrapper.h | 5 ----
arch/s390/include/asm/syscall_wrapper.h | 13 +--------
arch/x86/include/asm/syscall_wrapper.h | 34 +++---------------------
kernel/sys_ni.c | 14 ++++++++++
kernel/time/posix-stubs.c | 45 --------------------------------
6 files changed, 19 insertions(+), 96 deletions(-)
diff --git a/arch/arm64/include/asm/syscall_wrapper.h b/arch/arm64/include/asm/syscall_wrapper.h
index d977713ec0ba..abb57bc54305 100644
--- a/arch/arm64/include/asm/syscall_wrapper.h
+++ b/arch/arm64/include/asm/syscall_wrapper.h
@@ -44,9 +44,6 @@
return sys_ni_syscall(); \
}
-#define COMPAT_SYS_NI(name) \
- SYSCALL_ALIAS(__arm64_compat_sys_##name, sys_ni_posix_timers);
-
#endif /* CONFIG_COMPAT */
#define __SYSCALL_DEFINEx(x, name, ...) \
@@ -81,6 +78,5 @@
}
asmlinkage long __arm64_sys_ni_syscall(const struct pt_regs *__unused);
-#define SYS_NI(name) SYSCALL_ALIAS(__arm64_sys_##name, sys_ni_posix_timers);
#endif /* __ASM_SYSCALL_WRAPPER_H */
diff --git a/arch/riscv/include/asm/syscall_wrapper.h b/arch/riscv/include/asm/syscall_wrapper.h
index 1d7942c8a6cb..eeec04b7dae6 100644
--- a/arch/riscv/include/asm/syscall_wrapper.h
+++ b/arch/riscv/include/asm/syscall_wrapper.h
@@ -46,9 +46,6 @@ asmlinkage long __riscv_sys_ni_syscall(const struct pt_regs *);
return sys_ni_syscall(); \
}
-#define COMPAT_SYS_NI(name) \
- SYSCALL_ALIAS(__riscv_compat_sys_##name, sys_ni_posix_timers);
-
#endif /* CONFIG_COMPAT */
#define __SYSCALL_DEFINEx(x, name, ...) \
@@ -82,6 +79,4 @@ asmlinkage long __riscv_sys_ni_syscall(const struct pt_regs *);
return sys_ni_syscall(); \
}
-#define SYS_NI(name) SYSCALL_ALIAS(__riscv_sys_##name, sys_ni_posix_timers);
-
#endif /* __ASM_SYSCALL_WRAPPER_H */
diff --git a/arch/s390/include/asm/syscall_wrapper.h b/arch/s390/include/asm/syscall_wrapper.h
index 9286430fe729..35c1d1b860d8 100644
--- a/arch/s390/include/asm/syscall_wrapper.h
+++ b/arch/s390/include/asm/syscall_wrapper.h
@@ -63,10 +63,6 @@
cond_syscall(__s390x_sys_##name); \
cond_syscall(__s390_sys_##name)
-#define SYS_NI(name) \
- SYSCALL_ALIAS(__s390x_sys_##name, sys_ni_posix_timers); \
- SYSCALL_ALIAS(__s390_sys_##name, sys_ni_posix_timers)
-
#define COMPAT_SYSCALL_DEFINEx(x, name, ...) \
long __s390_compat_sys##name(struct pt_regs *regs); \
ALLOW_ERROR_INJECTION(__s390_compat_sys##name, ERRNO); \
@@ -85,15 +81,11 @@
/*
* As some compat syscalls may not be implemented, we need to expand
- * COND_SYSCALL_COMPAT in kernel/sys_ni.c and COMPAT_SYS_NI in
- * kernel/time/posix-stubs.c to cover this case as well.
+ * COND_SYSCALL_COMPAT in kernel/sys_ni.c to cover this case as well.
*/
#define COND_SYSCALL_COMPAT(name) \
cond_syscall(__s390_compat_sys_##name)
-#define COMPAT_SYS_NI(name) \
- SYSCALL_ALIAS(__s390_compat_sys_##name, sys_ni_posix_timers)
-
#define __S390_SYS_STUBx(x, name, ...) \
long __s390_sys##name(struct pt_regs *regs); \
ALLOW_ERROR_INJECTION(__s390_sys##name, ERRNO); \
@@ -124,9 +116,6 @@
#define COND_SYSCALL(name) \
cond_syscall(__s390x_sys_##name)
-#define SYS_NI(name) \
- SYSCALL_ALIAS(__s390x_sys_##name, sys_ni_posix_timers)
-
#define __S390_SYS_STUBx(x, fullname, name, ...)
#endif /* CONFIG_COMPAT */
diff --git a/arch/x86/include/asm/syscall_wrapper.h b/arch/x86/include/asm/syscall_wrapper.h
index fd2669b1cb2d..21f9407be5d3 100644
--- a/arch/x86/include/asm/syscall_wrapper.h
+++ b/arch/x86/include/asm/syscall_wrapper.h
@@ -86,9 +86,6 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs);
return sys_ni_syscall(); \
}
-#define __SYS_NI(abi, name) \
- SYSCALL_ALIAS(__##abi##_##name, sys_ni_posix_timers);
-
#ifdef CONFIG_X86_64
#define __X64_SYS_STUB0(name) \
__SYS_STUB0(x64, sys_##name)
@@ -100,13 +97,10 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs);
#define __X64_COND_SYSCALL(name) \
__COND_SYSCALL(x64, sys_##name)
-#define __X64_SYS_NI(name) \
- __SYS_NI(x64, sys_##name)
#else /* CONFIG_X86_64 */
#define __X64_SYS_STUB0(name)
#define __X64_SYS_STUBx(x, name, ...)
#define __X64_COND_SYSCALL(name)
-#define __X64_SYS_NI(name)
#endif /* CONFIG_X86_64 */
#if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION)
@@ -120,13 +114,10 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs);
#define __IA32_COND_SYSCALL(name) \
__COND_SYSCALL(ia32, sys_##name)
-#define __IA32_SYS_NI(name) \
- __SYS_NI(ia32, sys_##name)
#else /* CONFIG_X86_32 || CONFIG_IA32_EMULATION */
#define __IA32_SYS_STUB0(name)
#define __IA32_SYS_STUBx(x, name, ...)
#define __IA32_COND_SYSCALL(name)
-#define __IA32_SYS_NI(name)
#endif /* CONFIG_X86_32 || CONFIG_IA32_EMULATION */
#ifdef CONFIG_IA32_EMULATION
@@ -135,8 +126,7 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs);
* additional wrappers (aptly named __ia32_sys_xyzzy) which decode the
* ia32 regs in the proper order for shared or "common" syscalls. As some
* syscalls may not be implemented, we need to expand COND_SYSCALL in
- * kernel/sys_ni.c and SYS_NI in kernel/time/posix-stubs.c to cover this
- * case as well.
+ * kernel/sys_ni.c to cover this case as well.
*/
#define __IA32_COMPAT_SYS_STUB0(name) \
__SYS_STUB0(ia32, compat_sys_##name)
@@ -148,14 +138,10 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs);
#define __IA32_COMPAT_COND_SYSCALL(name) \
__COND_SYSCALL(ia32, compat_sys_##name)
-#define __IA32_COMPAT_SYS_NI(name) \
- __SYS_NI(ia32, compat_sys_##name)
-
#else /* CONFIG_IA32_EMULATION */
#define __IA32_COMPAT_SYS_STUB0(name)
#define __IA32_COMPAT_SYS_STUBx(x, name, ...)
#define __IA32_COMPAT_COND_SYSCALL(name)
-#define __IA32_COMPAT_SYS_NI(name)
#endif /* CONFIG_IA32_EMULATION */
@@ -175,13 +161,10 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs);
#define __X32_COMPAT_COND_SYSCALL(name) \
__COND_SYSCALL(x64, compat_sys_##name)
-#define __X32_COMPAT_SYS_NI(name) \
- __SYS_NI(x64, compat_sys_##name)
#else /* CONFIG_X86_X32_ABI */
#define __X32_COMPAT_SYS_STUB0(name)
#define __X32_COMPAT_SYS_STUBx(x, name, ...)
#define __X32_COMPAT_COND_SYSCALL(name)
-#define __X32_COMPAT_SYS_NI(name)
#endif /* CONFIG_X86_X32_ABI */
@@ -212,17 +195,12 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs);
/*
* As some compat syscalls may not be implemented, we need to expand
- * COND_SYSCALL_COMPAT in kernel/sys_ni.c and COMPAT_SYS_NI in
- * kernel/time/posix-stubs.c to cover this case as well.
+ * COND_SYSCALL_COMPAT in kernel/sys_ni.c to cover this case as well.
*/
#define COND_SYSCALL_COMPAT(name) \
__IA32_COMPAT_COND_SYSCALL(name) \
__X32_COMPAT_COND_SYSCALL(name)
-#define COMPAT_SYS_NI(name) \
- __IA32_COMPAT_SYS_NI(name) \
- __X32_COMPAT_SYS_NI(name)
-
#endif /* CONFIG_COMPAT */
#define __SYSCALL_DEFINEx(x, name, ...) \
@@ -243,8 +221,8 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs);
* As the generic SYSCALL_DEFINE0() macro does not decode any parameters for
* obvious reasons, and passing struct pt_regs *regs to it in %rdi does not
* hurt, we only need to re-define it here to keep the naming congruent to
- * SYSCALL_DEFINEx() -- which is essential for the COND_SYSCALL() and SYS_NI()
- * macros to work correctly.
+ * SYSCALL_DEFINEx() -- which is essential for the COND_SYSCALL() macro
+ * to work correctly.
*/
#define SYSCALL_DEFINE0(sname) \
SYSCALL_METADATA(_##sname, 0); \
@@ -257,10 +235,6 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs);
__X64_COND_SYSCALL(name) \
__IA32_COND_SYSCALL(name)
-#define SYS_NI(name) \
- __X64_SYS_NI(name) \
- __IA32_SYS_NI(name)
-
/*
* For VSYSCALLS, we need to declare these three syscalls with the new
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index e1a6e3c675c0..9a846439b36a 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -201,6 +201,20 @@ COND_SYSCALL(recvmmsg_time32);
COND_SYSCALL_COMPAT(recvmmsg_time32);
COND_SYSCALL_COMPAT(recvmmsg_time64);
+/* Posix timer syscalls may be configured out */
+COND_SYSCALL(timer_create);
+COND_SYSCALL(timer_gettime);
+COND_SYSCALL(timer_getoverrun);
+COND_SYSCALL(timer_settime);
+COND_SYSCALL(timer_delete);
+COND_SYSCALL(clock_adjtime);
+COND_SYSCALL(getitimer);
+COND_SYSCALL(setitimer);
+COND_SYSCALL(alarm);
+COND_SYSCALL_COMPAT(timer_create);
+COND_SYSCALL_COMPAT(getitimer);
+COND_SYSCALL_COMPAT(setitimer);
+
/*
* Architecture specific syscalls: see further below
*/
diff --git a/kernel/time/posix-stubs.c b/kernel/time/posix-stubs.c
index 828aeecbd1e8..9b6fcb8d85e7 100644
--- a/kernel/time/posix-stubs.c
+++ b/kernel/time/posix-stubs.c
@@ -17,40 +17,6 @@
#include <linux/time_namespace.h>
#include <linux/compat.h>
-#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
-/* Architectures may override SYS_NI and COMPAT_SYS_NI */
-#include <asm/syscall_wrapper.h>
-#endif
-
-asmlinkage long sys_ni_posix_timers(void)
-{
- pr_err_once("process %d (%s) attempted a POSIX timer syscall "
- "while CONFIG_POSIX_TIMERS is not set\n",
- current->pid, current->comm);
- return -ENOSYS;
-}
-
-#ifndef SYS_NI
-#define SYS_NI(name) SYSCALL_ALIAS(sys_##name, sys_ni_posix_timers)
-#endif
-
-#ifndef COMPAT_SYS_NI
-#define COMPAT_SYS_NI(name) SYSCALL_ALIAS(compat_sys_##name, sys_ni_posix_timers)
-#endif
-
-SYS_NI(timer_create);
-SYS_NI(timer_gettime);
-SYS_NI(timer_getoverrun);
-SYS_NI(timer_settime);
-SYS_NI(timer_delete);
-SYS_NI(clock_adjtime);
-SYS_NI(getitimer);
-SYS_NI(setitimer);
-SYS_NI(clock_adjtime32);
-#ifdef __ARCH_WANT_SYS_ALARM
-SYS_NI(alarm);
-#endif
-
/*
* We preserve minimal support for CLOCK_REALTIME and CLOCK_MONOTONIC
* as it is easy to remain compatible with little code. CLOCK_BOOTTIME
@@ -158,18 +124,7 @@ SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
which_clock);
}
-#ifdef CONFIG_COMPAT
-COMPAT_SYS_NI(timer_create);
-#endif
-
-#if defined(CONFIG_COMPAT) || defined(CONFIG_ALPHA)
-COMPAT_SYS_NI(getitimer);
-COMPAT_SYS_NI(setitimer);
-#endif
-
#ifdef CONFIG_COMPAT_32BIT_TIME
-SYS_NI(timer_settime32);
-SYS_NI(timer_gettime32);
SYSCALL_DEFINE2(clock_settime32, const clockid_t, which_clock,
struct old_timespec32 __user *, tp)
