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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
/*
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* Access to user system call parameters and results
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*
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* Copyright (C) 2008 Red Hat, Inc. All rights reserved.
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*
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* This copyrighted material is made available to anyone wishing to use,
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* modify, copy, or redistribute it subject to the terms and conditions
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* of the GNU General Public License v.2.
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*
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* See asm-generic/syscall.h for descriptions of what we must do here.
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*/
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#ifndef _ASM_SYSCALL_H
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#define _ASM_SYSCALL_H 1
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#include <linux/sched.h>
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/* ftrace syscalls requires exporting the sys_call_table */
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#ifdef CONFIG_FTRACE_SYSCALLS
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extern const unsigned long *sys_call_table;
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#endif /* CONFIG_FTRACE_SYSCALLS */
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static inline long syscall_get_nr(struct task_struct *task,
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struct pt_regs *regs)
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{
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return TRAP(regs) == 0xc00 ? regs->gpr[0] : -1L;
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}
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static inline void syscall_rollback(struct task_struct *task,
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struct pt_regs *regs)
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{
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regs->gpr[3] = regs->orig_gpr3;
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}
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static inline long syscall_get_error(struct task_struct *task,
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struct pt_regs *regs)
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{
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return (regs->ccr & 0x10000000) ? -regs->gpr[3] : 0;
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}
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static inline long syscall_get_return_value(struct task_struct *task,
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struct pt_regs *regs)
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{
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return regs->gpr[3];
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}
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static inline void syscall_set_return_value(struct task_struct *task,
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struct pt_regs *regs,
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int error, long val)
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{
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if (error) {
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regs->ccr |= 0x10000000L;
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regs->gpr[3] = -error;
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} else {
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regs->ccr &= ~0x10000000L;
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regs->gpr[3] = val;
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}
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}
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static inline void syscall_get_arguments(struct task_struct *task,
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struct pt_regs *regs,
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unsigned int i, unsigned int n,
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unsigned long *args)
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{
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BUG_ON(i + n > 6);
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#ifdef CONFIG_PPC64
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if (test_tsk_thread_flag(task, TIF_32BIT)) {
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/*
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* Zero-extend 32-bit argument values. The high bits are
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* garbage ignored by the actual syscall dispatch.
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*/
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while (n-- > 0)
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args[n] = (u32) regs->gpr[3 + i + n];
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return;
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}
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#endif
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memcpy(args, ®s->gpr[3 + i], n * sizeof(args[0]));
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}
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static inline void syscall_set_arguments(struct task_struct *task,
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struct pt_regs *regs,
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unsigned int i, unsigned int n,
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const unsigned long *args)
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{
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BUG_ON(i + n > 6);
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memcpy(®s->gpr[3 + i], args, n * sizeof(args[0]));
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}
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#endif /* _ASM_SYSCALL_H */
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