--- /dev/null
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for
+ * more details.
+ *
+ * Copied from i386: Ross Biro 1/23/92
+ */
+
+#include <linux/kernel.h>
+#include <linux/ptrace.h>
+#include <linux/kprobes.h>
+#include <linux/compat.h>
+#include <linux/uaccess.h>
+#include <linux/regset.h>
+#include <linux/elf.h>
+#include <linux/tracehook.h>
+#include <linux/context_tracking.h>
+#include <asm/traps.h>
+#include <arch/chip.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/syscalls.h>
+
+void user_enable_single_step(struct task_struct *child)
+{
+ set_tsk_thread_flag(child, TIF_SINGLESTEP);
+}
+
+void user_disable_single_step(struct task_struct *child)
+{
+ clear_tsk_thread_flag(child, TIF_SINGLESTEP);
+}
+
+/*
+ * Called by kernel/ptrace.c when detaching..
+ */
+void ptrace_disable(struct task_struct *child)
+{
+ clear_tsk_thread_flag(child, TIF_SINGLESTEP);
+
+ /*
+ * These two are currently unused, but will be set by arch_ptrace()
+ * and used in the syscall assembly when we do support them.
+ */
+ clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+}
+
+/*
+ * Get registers from task and ready the result for userspace.
+ * Note that we localize the API issues to getregs() and putregs() at
+ * some cost in performance, e.g. we need a full pt_regs copy for
+ * PEEKUSR, and two copies for POKEUSR. But in general we expect
+ * GETREGS/PUTREGS to be the API of choice anyway.
+ */
+static char *getregs(struct task_struct *child, struct pt_regs *uregs)
+{
+ *uregs = *task_pt_regs(child);
+
+ /* Set up flags ABI bits. */
+ uregs->flags = 0;
+#ifdef CONFIG_COMPAT
+ if (task_thread_info(child)->status & TS_COMPAT)
+ uregs->flags |= PT_FLAGS_COMPAT;
+#endif
+
+ return (char *)uregs;
+}
+
+/* Put registers back to task. */
+static void putregs(struct task_struct *child, struct pt_regs *uregs)
+{
+ struct pt_regs *regs = task_pt_regs(child);
+
+ /* Don't allow overwriting the kernel-internal flags word. */
+ uregs->flags = regs->flags;
+
+ /* Only allow setting the ICS bit in the ex1 word. */
+ uregs->ex1 = PL_ICS_EX1(USER_PL, EX1_ICS(uregs->ex1));
+
+ *regs = *uregs;
+}
+
+enum tile_regset {
+ REGSET_GPR,
+};
+
+static int tile_gpr_get(struct task_struct *target,
+ const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ void *kbuf, void __user *ubuf)
+{
+ struct pt_regs regs;
+
+ getregs(target, ®s);
+
+ return user_regset_copyout(&pos, &count, &kbuf, &ubuf, ®s, 0,
+ sizeof(regs));
+}
+
+static int tile_gpr_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;
+ struct pt_regs regs;
+
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, ®s, 0,
+ sizeof(regs));
+ if (ret)
+ return ret;
+
+ putregs(target, ®s);
+
+ return 0;
+}
+
+static const struct user_regset tile_user_regset[] = {
+ [REGSET_GPR] = {
+ .core_note_type = NT_PRSTATUS,
+ .n = ELF_NGREG,
+ .size = sizeof(elf_greg_t),
+ .align = sizeof(elf_greg_t),
+ .get = tile_gpr_get,
+ .set = tile_gpr_set,
+ },
+};
+
+static const struct user_regset_view tile_user_regset_view = {
+ .name = CHIP_ARCH_NAME,
+ .e_machine = ELF_ARCH,
+ .ei_osabi = ELF_OSABI,
+ .regsets = tile_user_regset,
+ .n = ARRAY_SIZE(tile_user_regset),
+};
+
+const struct user_regset_view *task_user_regset_view(struct task_struct *task)
+{
+ return &tile_user_regset_view;
+}
+
+long arch_ptrace(struct task_struct *child, long request,
+ unsigned long addr, unsigned long data)
+{
+ unsigned long __user *datap = (long __user __force *)data;
+ unsigned long tmp;
+ long ret = -EIO;
+ char *childreg;
+ struct pt_regs copyregs;
+
+ switch (request) {
+
+ case PTRACE_PEEKUSR: /* Read register from pt_regs. */
+ if (addr >= PTREGS_SIZE)
+ break;
+ childreg = getregs(child, ©regs) + addr;
+#ifdef CONFIG_COMPAT
+ if (is_compat_task()) {
+ if (addr & (sizeof(compat_long_t)-1))
+ break;
+ ret = put_user(*(compat_long_t *)childreg,
+ (compat_long_t __user *)datap);
+ } else
+#endif
+ {
+ if (addr & (sizeof(long)-1))
+ break;
+ ret = put_user(*(long *)childreg, datap);
+ }
+ break;
+
+ case PTRACE_POKEUSR: /* Write register in pt_regs. */
+ if (addr >= PTREGS_SIZE)
+ break;
+ childreg = getregs(child, ©regs) + addr;
+#ifdef CONFIG_COMPAT
+ if (is_compat_task()) {
+ if (addr & (sizeof(compat_long_t)-1))
+ break;
+ *(compat_long_t *)childreg = data;
+ } else
+#endif
+ {
+ if (addr & (sizeof(long)-1))
+ break;
+ *(long *)childreg = data;
+ }
+ putregs(child, ©regs);
+ ret = 0;
+ break;
+
+ case PTRACE_GETREGS: /* Get all registers from the child. */
+ ret = copy_regset_to_user(child, &tile_user_regset_view,
+ REGSET_GPR, 0,
+ sizeof(struct pt_regs), datap);
+ break;
+
+ case PTRACE_SETREGS: /* Set all registers in the child. */
+ ret = copy_regset_from_user(child, &tile_user_regset_view,
+ REGSET_GPR, 0,
+ sizeof(struct pt_regs), datap);
+ break;
+
+ case PTRACE_GETFPREGS: /* Get the child FPU state. */
+ case PTRACE_SETFPREGS: /* Set the child FPU state. */
+ break;
+
+ case PTRACE_SETOPTIONS:
+ /* Support TILE-specific ptrace options. */
+ BUILD_BUG_ON(PTRACE_O_MASK_TILE & PTRACE_O_MASK);
+ tmp = data & PTRACE_O_MASK_TILE;
+ data &= ~PTRACE_O_MASK_TILE;
+ ret = ptrace_request(child, request, addr, data);
+ if (ret == 0) {
+ unsigned int flags = child->ptrace;
+ flags &= ~(PTRACE_O_MASK_TILE << PT_OPT_FLAG_SHIFT);
+ flags |= (tmp << PT_OPT_FLAG_SHIFT);
+ child->ptrace = flags;
+ }
+ break;
+
+ default:
+#ifdef CONFIG_COMPAT
+ if (task_thread_info(current)->status & TS_COMPAT) {
+ ret = compat_ptrace_request(child, request,
+ addr, data);
+ break;
+ }
+#endif
+ ret = ptrace_request(child, request, addr, data);
+ break;
+ }
+
+ return ret;
+}
+
+#ifdef CONFIG_COMPAT
+/* Not used; we handle compat issues in arch_ptrace() directly. */
+long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
+ compat_ulong_t addr, compat_ulong_t data)
+{
+ BUG();
+}
+#endif
+
+int do_syscall_trace_enter(struct pt_regs *regs)
+{
+ u32 work = ACCESS_ONCE(current_thread_info()->flags);
+
+ /*
+ * If TIF_NOHZ is set, we are required to call user_exit() before
+ * doing anything that could touch RCU.
+ */
+ if (work & _TIF_NOHZ)
+ user_exit();
+
+ if (work & _TIF_SYSCALL_TRACE) {
+ if (tracehook_report_syscall_entry(regs))
+ regs->regs[TREG_SYSCALL_NR] = -1;
+ }
+
+ if (work & _TIF_SYSCALL_TRACEPOINT)
+ trace_sys_enter(regs, regs->regs[TREG_SYSCALL_NR]);
+
+ return regs->regs[TREG_SYSCALL_NR];
+}
+
+void do_syscall_trace_exit(struct pt_regs *regs)
+{
+ long errno;
+
+ /*
+ * We may come here right after calling schedule_user()
+ * in which case we can be in RCU user mode.
+ */
+ user_exit();
+
+ /*
+ * The standard tile calling convention returns the value (or negative
+ * errno) in r0, and zero (or positive errno) in r1.
+ * It saves a couple of cycles on the hot path to do this work in
+ * registers only as we return, rather than updating the in-memory
+ * struct ptregs.
+ */
+ errno = (long) regs->regs[0];
+ if (errno < 0 && errno > -4096)
+ regs->regs[1] = -errno;
+ else
+ regs->regs[1] = 0;
+
+ if (test_thread_flag(TIF_SYSCALL_TRACE))
+ tracehook_report_syscall_exit(regs, 0);
+
+ if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
+ trace_sys_exit(regs, regs->regs[0]);
+}
+
+void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs)
+{
+ struct siginfo info;
+
+ memset(&info, 0, sizeof(info));
+ info.si_signo = SIGTRAP;
+ info.si_code = TRAP_BRKPT;
+ info.si_addr = (void __user *) regs->pc;
+
+ /* Send us the fakey SIGTRAP */
+ force_sig_info(SIGTRAP, &info, tsk);
+}
+
+/* Handle synthetic interrupt delivered only by the simulator. */
+void __kprobes do_breakpoint(struct pt_regs* regs, int fault_num)
+{
+ enum ctx_state prev_state = exception_enter();
+ send_sigtrap(current, regs);
+ exception_exit(prev_state);
+}
Code Review / kvmfornfv.git / blobdiff