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x86/entry: Get rid of the sys_ni_syscall() indirection

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Invoking sys_ni_syscall() from a code path, which already knows that the
syscall number is invalid just to assign -ENOSYS to regs->ax is a pointless
exercise. It's even redundant as the low level entry code already has set
regs->ax to -ENOSYS on entry.

Remove the extra conditionals and the function calls.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Reviewed-by: Jinjie Ruan <ruanjinjie@huawei.com>
Link: https://patch.msgid.link/20260707190254.493733289@kernel.org
This commit is contained in:
Thomas Gleixner
2026-07-12 12:38:02 +02:00
parent 2b341c74db
commit 1b1f3b3e1b
2 changed files with 3 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files
arch/x86/entry/syscall_32.c
-2
View File
@@ -81,8 +81,6 @@ static __always_inline void do_syscall_32_irqs_on(struct pt_regs *regs, int nr)
if (likely(unr < IA32_NR_syscalls)) {
unr = array_index_nospec(unr, IA32_NR_syscalls);
regs->ax = ia32_sys_call(regs, unr);
} else if (nr != -1) {
regs->ax = __ia32_sys_ni_syscall(regs);
}
}
arch/x86/entry/syscall_64.c
+3 -7
View File
@@ -68,7 +68,7 @@ static __always_inline bool do_syscall_x64(struct pt_regs *regs, int nr)
return false;
}
static __always_inline bool do_syscall_x32(struct pt_regs *regs, int nr)
static __always_inline void do_syscall_x32(struct pt_regs *regs, int nr)
{
/*
* Adjust the starting offset of the table, and convert numbers
@@ -80,9 +80,7 @@ static __always_inline bool do_syscall_x32(struct pt_regs *regs, int nr)
if (IS_ENABLED(CONFIG_X86_X32_ABI) && likely(xnr < X32_NR_syscalls)) {
xnr = array_index_nospec(xnr, X32_NR_syscalls);
regs->ax = x32_sys_call(regs, xnr);
return true;
}
return false;
}
/* Returns true to return using SYSRET, or false to use IRET */
@@ -92,10 +90,8 @@ __visible noinstr bool do_syscall_64(struct pt_regs *regs, int nr)
instrumentation_begin();
if (!do_syscall_x64(regs, nr) && !do_syscall_x32(regs, nr) && nr != -1) {
/* Invalid system call, but still a system call. */
regs->ax = __x64_sys_ni_syscall(regs);
}
if (!do_syscall_x64(regs, nr))
do_syscall_x32(regs, nr);
instrumentation_end();
syscall_exit_to_user_mode(regs);