![Mark Rutland](/assets/img/avatar_default.png)
Please do not apply this to mainline directly, instead please re-run the coccinelle script shown below and apply its output. For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't harmful, and changing them results in churn. However, for some features, the read/write distinction is critical to correct operation. To distinguish these cases, separate read/write accessors must be used. This patch migrates (most) remaining ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following coccinelle script: ---- // Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and // WRITE_ONCE() // $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
317 lines
7.8 KiB
C
317 lines
7.8 KiB
C
/*
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* Copyright 2010 Tilera Corporation. All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation, version 2.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
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* NON INFRINGEMENT. See the GNU General Public License for
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* more details.
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*
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* Copied from i386: Ross Biro 1/23/92
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*/
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#include <linux/kernel.h>
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#include <linux/ptrace.h>
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#include <linux/kprobes.h>
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#include <linux/compat.h>
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#include <linux/uaccess.h>
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#include <linux/regset.h>
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#include <linux/elf.h>
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#include <linux/tracehook.h>
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#include <linux/context_tracking.h>
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#include <linux/sched/task_stack.h>
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#include <asm/traps.h>
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#include <arch/chip.h>
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#define CREATE_TRACE_POINTS
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#include <trace/events/syscalls.h>
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void user_enable_single_step(struct task_struct *child)
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{
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set_tsk_thread_flag(child, TIF_SINGLESTEP);
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}
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void user_disable_single_step(struct task_struct *child)
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{
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clear_tsk_thread_flag(child, TIF_SINGLESTEP);
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}
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/*
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* Called by kernel/ptrace.c when detaching..
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*/
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void ptrace_disable(struct task_struct *child)
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{
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clear_tsk_thread_flag(child, TIF_SINGLESTEP);
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/*
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* These two are currently unused, but will be set by arch_ptrace()
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* and used in the syscall assembly when we do support them.
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*/
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clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
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}
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/*
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* Get registers from task and ready the result for userspace.
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* Note that we localize the API issues to getregs() and putregs() at
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* some cost in performance, e.g. we need a full pt_regs copy for
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* PEEKUSR, and two copies for POKEUSR. But in general we expect
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* GETREGS/PUTREGS to be the API of choice anyway.
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*/
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static char *getregs(struct task_struct *child, struct pt_regs *uregs)
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{
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*uregs = *task_pt_regs(child);
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/* Set up flags ABI bits. */
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uregs->flags = 0;
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#ifdef CONFIG_COMPAT
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if (task_thread_info(child)->status & TS_COMPAT)
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uregs->flags |= PT_FLAGS_COMPAT;
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#endif
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return (char *)uregs;
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}
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/* Put registers back to task. */
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static void putregs(struct task_struct *child, struct pt_regs *uregs)
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{
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struct pt_regs *regs = task_pt_regs(child);
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/* Don't allow overwriting the kernel-internal flags word. */
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uregs->flags = regs->flags;
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/* Only allow setting the ICS bit in the ex1 word. */
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uregs->ex1 = PL_ICS_EX1(USER_PL, EX1_ICS(uregs->ex1));
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*regs = *uregs;
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}
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enum tile_regset {
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REGSET_GPR,
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};
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static int tile_gpr_get(struct task_struct *target,
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const struct user_regset *regset,
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unsigned int pos, unsigned int count,
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void *kbuf, void __user *ubuf)
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{
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struct pt_regs regs;
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getregs(target, ®s);
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return user_regset_copyout(&pos, &count, &kbuf, &ubuf, ®s, 0,
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sizeof(regs));
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}
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static int tile_gpr_set(struct task_struct *target,
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const struct user_regset *regset,
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unsigned int pos, unsigned int count,
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const void *kbuf, const void __user *ubuf)
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{
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int ret;
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struct pt_regs regs = *task_pt_regs(target);
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ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, ®s, 0,
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sizeof(regs));
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if (ret)
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return ret;
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putregs(target, ®s);
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return 0;
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}
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static const struct user_regset tile_user_regset[] = {
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[REGSET_GPR] = {
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.core_note_type = NT_PRSTATUS,
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.n = ELF_NGREG,
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.size = sizeof(elf_greg_t),
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.align = sizeof(elf_greg_t),
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.get = tile_gpr_get,
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.set = tile_gpr_set,
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},
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};
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static const struct user_regset_view tile_user_regset_view = {
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.name = CHIP_ARCH_NAME,
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.e_machine = ELF_ARCH,
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.ei_osabi = ELF_OSABI,
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.regsets = tile_user_regset,
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.n = ARRAY_SIZE(tile_user_regset),
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};
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const struct user_regset_view *task_user_regset_view(struct task_struct *task)
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{
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return &tile_user_regset_view;
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}
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long arch_ptrace(struct task_struct *child, long request,
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unsigned long addr, unsigned long data)
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{
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unsigned long __user *datap = (long __user __force *)data;
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unsigned long tmp;
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long ret = -EIO;
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char *childreg;
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struct pt_regs copyregs;
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switch (request) {
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case PTRACE_PEEKUSR: /* Read register from pt_regs. */
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if (addr >= PTREGS_SIZE)
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break;
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childreg = getregs(child, ©regs) + addr;
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#ifdef CONFIG_COMPAT
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if (is_compat_task()) {
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if (addr & (sizeof(compat_long_t)-1))
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break;
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ret = put_user(*(compat_long_t *)childreg,
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(compat_long_t __user *)datap);
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} else
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#endif
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{
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if (addr & (sizeof(long)-1))
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break;
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ret = put_user(*(long *)childreg, datap);
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}
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break;
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case PTRACE_POKEUSR: /* Write register in pt_regs. */
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if (addr >= PTREGS_SIZE)
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break;
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childreg = getregs(child, ©regs) + addr;
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#ifdef CONFIG_COMPAT
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if (is_compat_task()) {
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if (addr & (sizeof(compat_long_t)-1))
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break;
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*(compat_long_t *)childreg = data;
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} else
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#endif
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{
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if (addr & (sizeof(long)-1))
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break;
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*(long *)childreg = data;
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}
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putregs(child, ©regs);
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ret = 0;
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break;
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case PTRACE_GETREGS: /* Get all registers from the child. */
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ret = copy_regset_to_user(child, &tile_user_regset_view,
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REGSET_GPR, 0,
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sizeof(struct pt_regs), datap);
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break;
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case PTRACE_SETREGS: /* Set all registers in the child. */
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ret = copy_regset_from_user(child, &tile_user_regset_view,
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REGSET_GPR, 0,
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sizeof(struct pt_regs), datap);
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break;
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case PTRACE_GETFPREGS: /* Get the child FPU state. */
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case PTRACE_SETFPREGS: /* Set the child FPU state. */
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break;
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case PTRACE_SETOPTIONS:
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/* Support TILE-specific ptrace options. */
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BUILD_BUG_ON(PTRACE_O_MASK_TILE & PTRACE_O_MASK);
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tmp = data & PTRACE_O_MASK_TILE;
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data &= ~PTRACE_O_MASK_TILE;
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ret = ptrace_request(child, request, addr, data);
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if (ret == 0) {
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unsigned int flags = child->ptrace;
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flags &= ~(PTRACE_O_MASK_TILE << PT_OPT_FLAG_SHIFT);
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flags |= (tmp << PT_OPT_FLAG_SHIFT);
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child->ptrace = flags;
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}
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break;
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default:
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#ifdef CONFIG_COMPAT
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if (task_thread_info(current)->status & TS_COMPAT) {
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ret = compat_ptrace_request(child, request,
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addr, data);
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break;
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}
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#endif
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ret = ptrace_request(child, request, addr, data);
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break;
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}
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return ret;
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}
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#ifdef CONFIG_COMPAT
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/* Not used; we handle compat issues in arch_ptrace() directly. */
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long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
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compat_ulong_t addr, compat_ulong_t data)
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{
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BUG();
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}
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#endif
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int do_syscall_trace_enter(struct pt_regs *regs)
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{
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u32 work = READ_ONCE(current_thread_info()->flags);
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if ((work & _TIF_SYSCALL_TRACE) &&
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tracehook_report_syscall_entry(regs)) {
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regs->regs[TREG_SYSCALL_NR] = -1;
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return -1;
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}
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if (secure_computing(NULL) == -1)
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return -1;
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if (work & _TIF_SYSCALL_TRACEPOINT)
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trace_sys_enter(regs, regs->regs[TREG_SYSCALL_NR]);
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return regs->regs[TREG_SYSCALL_NR];
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}
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void do_syscall_trace_exit(struct pt_regs *regs)
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{
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long errno;
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/*
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* The standard tile calling convention returns the value (or negative
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* errno) in r0, and zero (or positive errno) in r1.
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* It saves a couple of cycles on the hot path to do this work in
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* registers only as we return, rather than updating the in-memory
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* struct ptregs.
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*/
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errno = (long) regs->regs[0];
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if (errno < 0 && errno > -4096)
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regs->regs[1] = -errno;
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else
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regs->regs[1] = 0;
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if (test_thread_flag(TIF_SYSCALL_TRACE))
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tracehook_report_syscall_exit(regs, 0);
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if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
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trace_sys_exit(regs, regs->regs[0]);
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}
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void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs)
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{
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struct siginfo info;
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memset(&info, 0, sizeof(info));
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info.si_signo = SIGTRAP;
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info.si_code = TRAP_BRKPT;
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info.si_addr = (void __user *) regs->pc;
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/* Send us the fakey SIGTRAP */
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force_sig_info(SIGTRAP, &info, tsk);
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}
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/* Handle synthetic interrupt delivered only by the simulator. */
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void __kprobes do_breakpoint(struct pt_regs* regs, int fault_num)
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{
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send_sigtrap(current, regs);
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}
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