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linux/arch/sh/kernel/ptrace_32.c
Peter Zijlstra a8b0ca17b8 perf: Remove the nmi parameter from the swevent and overflow interface 
The nmi parameter indicated if we could do wakeups from the current
context, if not, we would set some state and self-IPI and let the
resulting interrupt do the wakeup.

For the various event classes:

  - hardware: nmi=0; PMI is in fact an NMI or we run irq_work_run from
    the PMI-tail (ARM etc.)
  - tracepoint: nmi=0; since tracepoint could be from NMI context.
  - software: nmi=[0,1]; some, like the schedule thing cannot
    perform wakeups, and hence need 0.

As one can see, there is very little nmi=1 usage, and the down-side of
not using it is that on some platforms some software events can have a
jiffy delay in wakeup (when arch_irq_work_raise isn't implemented).

The up-side however is that we can remove the nmi parameter and save a
bunch of conditionals in fast paths.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Michael Cree <mcree@orcon.net.nz>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Don Zickus <dzickus@redhat.com>
Link: http://lkml.kernel.org/n/tip-agjev8eu666tvknpb3iaj0fg@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-01 11:06:35 +02:00

542 lines
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/*
* SuperH process tracing
*
* Copyright (C) 1999, 2000 Kaz Kojima & Niibe Yutaka
* Copyright (C) 2002 - 2009 Paul Mundt
*
* Audit support by Yuichi Nakamura <ynakam@hitachisoft.jp>
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/security.h>
#include <linux/signal.h>
#include <linux/io.h>
#include <linux/audit.h>
#include <linux/seccomp.h>
#include <linux/tracehook.h>
#include <linux/elf.h>
#include <linux/regset.h>
#include <linux/hw_breakpoint.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/processor.h>
#include <asm/mmu_context.h>
#include <asm/syscalls.h>
#include <asm/fpu.h>
#define CREATE_TRACE_POINTS
#include <trace/events/syscalls.h>
/*
* This routine will get a word off of the process kernel stack.
*/
static inline int get_stack_long(struct task_struct *task, int offset)
{
unsigned char *stack;
stack = (unsigned char *)task_pt_regs(task);
stack += offset;
return (*((int *)stack));
}
/*
* This routine will put a word on the process kernel stack.
*/
static inline int put_stack_long(struct task_struct *task, int offset,
unsigned long data)
{
unsigned char *stack;
stack = (unsigned char *)task_pt_regs(task);
stack += offset;
*(unsigned long *) stack = data;
return 0;
}
void ptrace_triggered(struct perf_event *bp,
struct perf_sample_data *data, struct pt_regs *regs)
{
struct perf_event_attr attr;
/*
* Disable the breakpoint request here since ptrace has defined a
* one-shot behaviour for breakpoint exceptions.
*/
attr = bp->attr;
attr.disabled = true;
modify_user_hw_breakpoint(bp, &attr);
}
static int set_single_step(struct task_struct *tsk, unsigned long addr)
{
struct thread_struct *thread = &tsk->thread;
struct perf_event *bp;
struct perf_event_attr attr;
bp = thread->ptrace_bps[0];
if (!bp) {
ptrace_breakpoint_init(&attr);
attr.bp_addr = addr;
attr.bp_len = HW_BREAKPOINT_LEN_2;
attr.bp_type = HW_BREAKPOINT_R;
bp = register_user_hw_breakpoint(&attr, ptrace_triggered, tsk);
if (IS_ERR(bp))
return PTR_ERR(bp);
thread->ptrace_bps[0] = bp;
} else {
int err;
attr = bp->attr;
attr.bp_addr = addr;
/* reenable breakpoint */
attr.disabled = false;
err = modify_user_hw_breakpoint(bp, &attr);
if (unlikely(err))
return err;
}
return 0;
}
void user_enable_single_step(struct task_struct *child)
{
unsigned long pc = get_stack_long(child, offsetof(struct pt_regs, pc));
set_tsk_thread_flag(child, TIF_SINGLESTEP);
if (ptrace_get_breakpoints(child) < 0)
return;
set_single_step(child, pc);
ptrace_put_breakpoints(child);
}
void user_disable_single_step(struct task_struct *child)
{
clear_tsk_thread_flag(child, TIF_SINGLESTEP);
}
/*
* Called by kernel/ptrace.c when detaching..
*
* Make sure single step bits etc are not set.
*/
void ptrace_disable(struct task_struct *child)
{
user_disable_single_step(child);
}
static int genregs_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
const struct pt_regs *regs = task_pt_regs(target);
int ret;
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
regs->regs,
0, 16 * sizeof(unsigned long));
if (!ret)
/* PC, PR, SR, GBR, MACH, MACL, TRA */
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
&regs->pc,
offsetof(struct pt_regs, pc),
sizeof(struct pt_regs));
if (!ret)
ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
sizeof(struct pt_regs), -1);
return ret;
}
static int genregs_set(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
struct pt_regs *regs = task_pt_regs(target);
int ret;
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
regs->regs,
0, 16 * sizeof(unsigned long));
if (!ret && count > 0)
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
&regs->pc,
offsetof(struct pt_regs, pc),
sizeof(struct pt_regs));
if (!ret)
ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
sizeof(struct pt_regs), -1);
return ret;
}
#ifdef CONFIG_SH_FPU
int fpregs_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
int ret;
ret = init_fpu(target);
if (ret)
return ret;
if ((boot_cpu_data.flags & CPU_HAS_FPU))
return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
&target->thread.xstate->hardfpu, 0, -1);
return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
&target->thread.xstate->softfpu, 0, -1);
}
static int fpregs_set(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
int ret;
ret = init_fpu(target);
if (ret)
return ret;
set_stopped_child_used_math(target);
if ((boot_cpu_data.flags & CPU_HAS_FPU))
return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
&target->thread.xstate->hardfpu, 0, -1);
return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
&target->thread.xstate->softfpu, 0, -1);
}
static int fpregs_active(struct task_struct *target,
const struct user_regset *regset)
{
return tsk_used_math(target) ? regset->n : 0;
}
#endif
#ifdef CONFIG_SH_DSP
static int dspregs_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
const struct pt_dspregs *regs =
(struct pt_dspregs *)&target->thread.dsp_status.dsp_regs;
int ret;
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs,
0, sizeof(struct pt_dspregs));
if (!ret)
ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
sizeof(struct pt_dspregs), -1);
return ret;
}
static int dspregs_set(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
struct pt_dspregs *regs =
(struct pt_dspregs *)&target->thread.dsp_status.dsp_regs;
int ret;
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs,
0, sizeof(struct pt_dspregs));
if (!ret)
ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
sizeof(struct pt_dspregs), -1);
return ret;
}
static int dspregs_active(struct task_struct *target,
const struct user_regset *regset)
{
struct pt_regs *regs = task_pt_regs(target);
return regs->sr & SR_DSP ? regset->n : 0;
}
#endif
const struct pt_regs_offset regoffset_table[] = {
REGS_OFFSET_NAME(0),
REGS_OFFSET_NAME(1),
REGS_OFFSET_NAME(2),
REGS_OFFSET_NAME(3),
REGS_OFFSET_NAME(4),
REGS_OFFSET_NAME(5),
REGS_OFFSET_NAME(6),
REGS_OFFSET_NAME(7),
REGS_OFFSET_NAME(8),
REGS_OFFSET_NAME(9),
REGS_OFFSET_NAME(10),
REGS_OFFSET_NAME(11),
REGS_OFFSET_NAME(12),
REGS_OFFSET_NAME(13),
REGS_OFFSET_NAME(14),
REGS_OFFSET_NAME(15),
REG_OFFSET_NAME(pc),
REG_OFFSET_NAME(pr),
REG_OFFSET_NAME(sr),
REG_OFFSET_NAME(gbr),
REG_OFFSET_NAME(mach),
REG_OFFSET_NAME(macl),
REG_OFFSET_NAME(tra),
REG_OFFSET_END,
};
/*
* These are our native regset flavours.
*/
enum sh_regset {
REGSET_GENERAL,
#ifdef CONFIG_SH_FPU
REGSET_FPU,
#endif
#ifdef CONFIG_SH_DSP
REGSET_DSP,
#endif
};
static const struct user_regset sh_regsets[] = {
/*
* Format is:
* R0 --> R15
* PC, PR, SR, GBR, MACH, MACL, TRA
*/
[REGSET_GENERAL] = {
.core_note_type = NT_PRSTATUS,
.n = ELF_NGREG,
.size = sizeof(long),
.align = sizeof(long),
.get = genregs_get,
.set = genregs_set,
},
#ifdef CONFIG_SH_FPU
[REGSET_FPU] = {
.core_note_type = NT_PRFPREG,
.n = sizeof(struct user_fpu_struct) / sizeof(long),
.size = sizeof(long),
.align = sizeof(long),
.get = fpregs_get,
.set = fpregs_set,
.active = fpregs_active,
},
#endif
#ifdef CONFIG_SH_DSP
[REGSET_DSP] = {
.n = sizeof(struct pt_dspregs) / sizeof(long),
.size = sizeof(long),
.align = sizeof(long),
.get = dspregs_get,
.set = dspregs_set,
.active = dspregs_active,
},
#endif
};
static const struct user_regset_view user_sh_native_view = {
.name = "sh",
.e_machine = EM_SH,
.regsets = sh_regsets,
.n = ARRAY_SIZE(sh_regsets),
};
const struct user_regset_view *task_user_regset_view(struct task_struct *task)
{
return &user_sh_native_view;
}
long arch_ptrace(struct task_struct *child, long request,
unsigned long addr, unsigned long data)
{
unsigned long __user *datap = (unsigned long __user *)data;
int ret;
switch (request) {
/* read the word at location addr in the USER area. */
case PTRACE_PEEKUSR: {
unsigned long tmp;
ret = -EIO;
if ((addr & 3) || addr < 0 ||
addr > sizeof(struct user) - 3)
break;
if (addr < sizeof(struct pt_regs))
tmp = get_stack_long(child, addr);
else if (addr >= offsetof(struct user, fpu) &&
addr < offsetof(struct user, u_fpvalid)) {
if (!tsk_used_math(child)) {
if (addr == offsetof(struct user, fpu.fpscr))
tmp = FPSCR_INIT;
else
tmp = 0;
} else {
unsigned long index;
ret = init_fpu(child);
if (ret)
break;
index = addr - offsetof(struct user, fpu);
tmp = ((unsigned long *)child->thread.xstate)
[index >> 2];
}
} else if (addr == offsetof(struct user, u_fpvalid))
tmp = !!tsk_used_math(child);
else if (addr == PT_TEXT_ADDR)
tmp = child->mm->start_code;
else if (addr == PT_DATA_ADDR)
tmp = child->mm->start_data;
else if (addr == PT_TEXT_END_ADDR)
tmp = child->mm->end_code;
else if (addr == PT_TEXT_LEN)
tmp = child->mm->end_code - child->mm->start_code;
else
tmp = 0;
ret = put_user(tmp, datap);
break;
}
case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
ret = -EIO;
if ((addr & 3) || addr < 0 ||
addr > sizeof(struct user) - 3)
break;
if (addr < sizeof(struct pt_regs))
ret = put_stack_long(child, addr, data);
else if (addr >= offsetof(struct user, fpu) &&
addr < offsetof(struct user, u_fpvalid)) {
unsigned long index;
ret = init_fpu(child);
if (ret)
break;
index = addr - offsetof(struct user, fpu);
set_stopped_child_used_math(child);
((unsigned long *)child->thread.xstate)
[index >> 2] = data;
ret = 0;
} else if (addr == offsetof(struct user, u_fpvalid)) {
conditional_stopped_child_used_math(data, child);
ret = 0;
}
break;
case PTRACE_GETREGS:
return copy_regset_to_user(child, &user_sh_native_view,
REGSET_GENERAL,
0, sizeof(struct pt_regs),
datap);
case PTRACE_SETREGS:
return copy_regset_from_user(child, &user_sh_native_view,
REGSET_GENERAL,
0, sizeof(struct pt_regs),
datap);
#ifdef CONFIG_SH_FPU
case PTRACE_GETFPREGS:
return copy_regset_to_user(child, &user_sh_native_view,
REGSET_FPU,
0, sizeof(struct user_fpu_struct),
datap);
case PTRACE_SETFPREGS:
return copy_regset_from_user(child, &user_sh_native_view,
REGSET_FPU,
0, sizeof(struct user_fpu_struct),
datap);
#endif
#ifdef CONFIG_SH_DSP
case PTRACE_GETDSPREGS:
return copy_regset_to_user(child, &user_sh_native_view,
REGSET_DSP,
0, sizeof(struct pt_dspregs),
datap);
case PTRACE_SETDSPREGS:
return copy_regset_from_user(child, &user_sh_native_view,
REGSET_DSP,
0, sizeof(struct pt_dspregs),
datap);
#endif
default:
ret = ptrace_request(child, request, addr, data);
break;
}
return ret;
}
static inline int audit_arch(void)
{
int arch = EM_SH;
#ifdef CONFIG_CPU_LITTLE_ENDIAN
arch |= __AUDIT_ARCH_LE;
#endif
return arch;
}
asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
{
long ret = 0;
secure_computing(regs->regs[0]);
if (test_thread_flag(TIF_SYSCALL_TRACE) &&
tracehook_report_syscall_entry(regs))
/*
* Tracing decided this syscall should not happen.
* We'll return a bogus call number to get an ENOSYS
* error, but leave the original number in regs->regs[0].
*/
ret = -1L;
if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
trace_sys_enter(regs, regs->regs[0]);
if (unlikely(current->audit_context))
audit_syscall_entry(audit_arch(), regs->regs[3],
regs->regs[4], regs->regs[5],
regs->regs[6], regs->regs[7]);
return ret ?: regs->regs[0];
}
asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
{
int step;
if (unlikely(current->audit_context))
audit_syscall_exit(AUDITSC_RESULT(regs->regs[0]),
regs->regs[0]);
if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
trace_sys_exit(regs, regs->regs[0]);
step = test_thread_flag(TIF_SINGLESTEP);
if (step || test_thread_flag(TIF_SYSCALL_TRACE))
tracehook_report_syscall_exit(regs, step);
}
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