mirror of
https://github.com/torvalds/linux.git
synced 2024-11-18 18:11:56 +00:00
02424d8966
This patch implements the raw syscall tracepoints on PowerPC and exports
them for ftrace syscalls to use.
To minimise reworking existing code, I slightly re-ordered the thread
info flags such that the new TIF_SYSCALL_TRACEPOINT bit would still fit
within the 16 bits of the andi. instruction's UI field. The instructions
in question are in /arch/powerpc/kernel/entry_{32,64}.S to and the
_TIF_SYSCALL_T_OR_A with the thread flags to see if system call tracing
is enabled.
In the case of 64bit PowerPC, arch_syscall_addr and
arch_syscall_match_sym_name are overridden to allow ftrace syscalls to
work given the unusual system call table structure and symbol names that
start with a period.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
90 lines
2.2 KiB
C
90 lines
2.2 KiB
C
/*
|
|
* Access to user system call parameters and results
|
|
*
|
|
* Copyright (C) 2008 Red Hat, Inc. All rights reserved.
|
|
*
|
|
* This copyrighted material is made available to anyone wishing to use,
|
|
* modify, copy, or redistribute it subject to the terms and conditions
|
|
* of the GNU General Public License v.2.
|
|
*
|
|
* See asm-generic/syscall.h for descriptions of what we must do here.
|
|
*/
|
|
|
|
#ifndef _ASM_SYSCALL_H
|
|
#define _ASM_SYSCALL_H 1
|
|
|
|
#include <linux/sched.h>
|
|
|
|
/* ftrace syscalls requires exporting the sys_call_table */
|
|
#ifdef CONFIG_FTRACE_SYSCALLS
|
|
extern const unsigned long *sys_call_table;
|
|
#endif /* CONFIG_FTRACE_SYSCALLS */
|
|
|
|
static inline long syscall_get_nr(struct task_struct *task,
|
|
struct pt_regs *regs)
|
|
{
|
|
return TRAP(regs) == 0xc00 ? regs->gpr[0] : -1L;
|
|
}
|
|
|
|
static inline void syscall_rollback(struct task_struct *task,
|
|
struct pt_regs *regs)
|
|
{
|
|
regs->gpr[3] = regs->orig_gpr3;
|
|
}
|
|
|
|
static inline long syscall_get_error(struct task_struct *task,
|
|
struct pt_regs *regs)
|
|
{
|
|
return (regs->ccr & 0x10000000) ? -regs->gpr[3] : 0;
|
|
}
|
|
|
|
static inline long syscall_get_return_value(struct task_struct *task,
|
|
struct pt_regs *regs)
|
|
{
|
|
return regs->gpr[3];
|
|
}
|
|
|
|
static inline void syscall_set_return_value(struct task_struct *task,
|
|
struct pt_regs *regs,
|
|
int error, long val)
|
|
{
|
|
if (error) {
|
|
regs->ccr |= 0x10000000L;
|
|
regs->gpr[3] = -error;
|
|
} else {
|
|
regs->ccr &= ~0x10000000L;
|
|
regs->gpr[3] = val;
|
|
}
|
|
}
|
|
|
|
static inline void syscall_get_arguments(struct task_struct *task,
|
|
struct pt_regs *regs,
|
|
unsigned int i, unsigned int n,
|
|
unsigned long *args)
|
|
{
|
|
BUG_ON(i + n > 6);
|
|
#ifdef CONFIG_PPC64
|
|
if (test_tsk_thread_flag(task, TIF_32BIT)) {
|
|
/*
|
|
* Zero-extend 32-bit argument values. The high bits are
|
|
* garbage ignored by the actual syscall dispatch.
|
|
*/
|
|
while (n-- > 0)
|
|
args[n] = (u32) regs->gpr[3 + i + n];
|
|
return;
|
|
}
|
|
#endif
|
|
memcpy(args, ®s->gpr[3 + i], n * 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->gpr[3 + i], args, n * sizeof(args[0]));
|
|
}
|
|
|
|
#endif /* _ASM_SYSCALL_H */
|