mirror of
https://github.com/brain-hackers/linux-brain.git
synced 2024-06-09 23:36:23 +09:00
b35f549df1
At Linux Plumbers, Andy Lutomirski approached me and pointed out that the function call syscall_get_arguments() implemented in x86 was horribly written and not optimized for the standard case of passing in 0 and 6 for the starting index and the number of system calls to get. When looking at all the users of this function, I discovered that all instances pass in only 0 and 6 for these arguments. Instead of having this function handle different cases that are never used, simply rewrite it to return the first 6 arguments of a system call. This should help out the performance of tracing system calls by ptrace, ftrace and perf. Link: http://lkml.kernel.org/r/20161107213233.754809394@goodmis.org Cc: Oleg Nesterov <oleg@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Dave Martin <dave.martin@arm.com> Cc: "Dmitry V. Levin" <ldv@altlinux.org> Cc: x86@kernel.org Cc: linux-snps-arc@lists.infradead.org Cc: linux-kernel@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-c6x-dev@linux-c6x.org Cc: uclinux-h8-devel@lists.sourceforge.jp Cc: linux-hexagon@vger.kernel.org Cc: linux-ia64@vger.kernel.org Cc: linux-mips@vger.kernel.org Cc: nios2-dev@lists.rocketboards.org Cc: openrisc@lists.librecores.org Cc: linux-parisc@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-riscv@lists.infradead.org Cc: linux-s390@vger.kernel.org Cc: linux-sh@vger.kernel.org Cc: sparclinux@vger.kernel.org Cc: linux-um@lists.infradead.org Cc: linux-xtensa@linux-xtensa.org Cc: linux-arch@vger.kernel.org Acked-by: Paul Burton <paul.burton@mips.com> # MIPS parts Acked-by: Max Filippov <jcmvbkbc@gmail.com> # For xtensa changes Acked-by: Will Deacon <will.deacon@arm.com> # For the arm64 bits Reviewed-by: Thomas Gleixner <tglx@linutronix.de> # for x86 Reviewed-by: Dmitry V. Levin <ldv@altlinux.org> Reported-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
78 lines
1.7 KiB
C
78 lines
1.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef __ASM_SH_SYSCALL_64_H
|
|
#define __ASM_SH_SYSCALL_64_H
|
|
|
|
#include <uapi/linux/audit.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/sched.h>
|
|
#include <asm/ptrace.h>
|
|
|
|
/* The system call number is given by the user in R9 */
|
|
static inline long syscall_get_nr(struct task_struct *task,
|
|
struct pt_regs *regs)
|
|
{
|
|
return (regs->syscall_nr >= 0) ? regs->regs[9] : -1L;
|
|
}
|
|
|
|
static inline void syscall_rollback(struct task_struct *task,
|
|
struct pt_regs *regs)
|
|
{
|
|
/*
|
|
* XXX: This needs some thought. On SH we don't
|
|
* save away the original R9 value anywhere.
|
|
*/
|
|
}
|
|
|
|
static inline long syscall_get_error(struct task_struct *task,
|
|
struct pt_regs *regs)
|
|
{
|
|
return IS_ERR_VALUE(regs->regs[9]) ? regs->regs[9] : 0;
|
|
}
|
|
|
|
static inline long syscall_get_return_value(struct task_struct *task,
|
|
struct pt_regs *regs)
|
|
{
|
|
return regs->regs[9];
|
|
}
|
|
|
|
static inline void syscall_set_return_value(struct task_struct *task,
|
|
struct pt_regs *regs,
|
|
int error, long val)
|
|
{
|
|
if (error)
|
|
regs->regs[9] = -error;
|
|
else
|
|
regs->regs[9] = val;
|
|
}
|
|
|
|
static inline void syscall_get_arguments(struct task_struct *task,
|
|
struct pt_regs *regs,
|
|
unsigned long *args)
|
|
{
|
|
memcpy(args, ®s->regs[2], 6 * sizeof(args[0]));
|
|
}
|
|
|
|
static inline void syscall_set_arguments(struct task_struct *task,
|
|
struct pt_regs *regs,
|
|
unsigned int i, unsigned int n,
|
|
const unsigned long *args)
|
|
{
|
|
BUG_ON(i + n > 6);
|
|
memcpy(®s->regs[2 + i], args, n * sizeof(args[0]));
|
|
}
|
|
|
|
static inline int syscall_get_arch(void)
|
|
{
|
|
int arch = AUDIT_ARCH_SH;
|
|
|
|
#ifdef CONFIG_64BIT
|
|
arch |= __AUDIT_ARCH_64BIT;
|
|
#endif
|
|
#ifdef CONFIG_CPU_LITTLE_ENDIAN
|
|
arch |= __AUDIT_ARCH_LE;
|
|
#endif
|
|
|
|
return arch;
|
|
}
|
|
#endif /* __ASM_SH_SYSCALL_64_H */
|