/* By Ross Biro 1/23/92 */ /* * Pentium III FXSR, SSE support * Gareth Hughes , May 2000 * * BTS tracing * Markus Metzger , Dec 2007 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "tls.h" #define CREATE_TRACE_POINTS #include enum x86_regset { REGSET_GENERAL, REGSET_FP, REGSET_XFP, REGSET_IOPERM64 = REGSET_XFP, REGSET_XSTATE, REGSET_TLS, REGSET_IOPERM32, }; struct pt_regs_offset { const char *name; int offset; }; #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)} #define REG_OFFSET_END {.name = NULL, .offset = 0} static const struct pt_regs_offset regoffset_table[] = { #ifdef CONFIG_X86_64 REG_OFFSET_NAME(r15), REG_OFFSET_NAME(r14), REG_OFFSET_NAME(r13), REG_OFFSET_NAME(r12), REG_OFFSET_NAME(r11), REG_OFFSET_NAME(r10), REG_OFFSET_NAME(r9), REG_OFFSET_NAME(r8), #endif REG_OFFSET_NAME(bx), REG_OFFSET_NAME(cx), REG_OFFSET_NAME(dx), REG_OFFSET_NAME(si), REG_OFFSET_NAME(di), REG_OFFSET_NAME(bp), REG_OFFSET_NAME(ax), #ifdef CONFIG_X86_32 REG_OFFSET_NAME(ds), REG_OFFSET_NAME(es), REG_OFFSET_NAME(fs), REG_OFFSET_NAME(gs), #endif REG_OFFSET_NAME(orig_ax), REG_OFFSET_NAME(ip), REG_OFFSET_NAME(cs), REG_OFFSET_NAME(flags), REG_OFFSET_NAME(sp), REG_OFFSET_NAME(ss), REG_OFFSET_END, }; /** * regs_query_register_offset() - query register offset from its name * @name: the name of a register * * regs_query_register_offset() returns the offset of a register in struct * pt_regs from its name. If the name is invalid, this returns -EINVAL; */ int regs_query_register_offset(const char *name) { const struct pt_regs_offset *roff; for (roff = regoffset_table; roff->name != NULL; roff++) if (!strcmp(roff->name, name)) return roff->offset; return -EINVAL; } /** * regs_query_register_name() - query register name from its offset * @offset: the offset of a register in struct pt_regs. * * regs_query_register_name() returns the name of a register from its * offset in struct pt_regs. If the @offset is invalid, this returns NULL; */ const char *regs_query_register_name(unsigned int offset) { const struct pt_regs_offset *roff; for (roff = regoffset_table; roff->name != NULL; roff++) if (roff->offset == offset) return roff->name; return NULL; } static const int arg_offs_table[] = { #ifdef CONFIG_X86_32 [0] = offsetof(struct pt_regs, ax), [1] = offsetof(struct pt_regs, dx), [2] = offsetof(struct pt_regs, cx) #else /* CONFIG_X86_64 */ [0] = offsetof(struct pt_regs, di), [1] = offsetof(struct pt_regs, si), [2] = offsetof(struct pt_regs, dx), [3] = offsetof(struct pt_regs, cx), [4] = offsetof(struct pt_regs, r8), [5] = offsetof(struct pt_regs, r9) #endif }; /** * regs_get_argument_nth() - get Nth argument at function call * @regs: pt_regs which contains registers at function entry. * @n: argument number. * * regs_get_argument_nth() returns @n th argument of a function call. * Since usually the kernel stack will be changed right after function entry, * you must use this at function entry. If the @n th entry is NOT in the * kernel stack or pt_regs, this returns 0. */ unsigned long regs_get_argument_nth(struct pt_regs *regs, unsigned int n) { if (n < ARRAY_SIZE(arg_offs_table)) return *(unsigned long *)((char *)regs + arg_offs_table[n]); else { /* * The typical case: arg n is on the stack. * (Note: stack[0] = return address, so skip it) */ n -= ARRAY_SIZE(arg_offs_table); return regs_get_kernel_stack_nth(regs, 1 + n); } } /* * does not yet catch signals sent when the child dies. * in exit.c or in signal.c. */ /* * Determines which flags the user has access to [1 = access, 0 = no access]. */ #define FLAG_MASK_32 ((unsigned long) \ (X86_EFLAGS_CF | X86_EFLAGS_PF | \ X86_EFLAGS_AF | X86_EFLAGS_ZF | \ X86_EFLAGS_SF | X86_EFLAGS_TF | \ X86_EFLAGS_DF | X86_EFLAGS_OF | \ X86_EFLAGS_RF | X86_EFLAGS_AC)) /* * Determines whether a value may be installed in a segment register. */ static inline bool invalid_selector(u16 value) { return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL); } #ifdef CONFIG_X86_32 #define FLAG_MASK FLAG_MASK_32 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno) { BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0); return ®s->bx + (regno >> 2); } static u16 get_segment_reg(struct task_struct *task, unsigned long offset) { /* * Returning the value truncates it to 16 bits. */ unsigned int retval; if (offset != offsetof(struct user_regs_struct, gs)) retval = *pt_regs_access(task_pt_regs(task), offset); else { if (task == current) retval = get_user_gs(task_pt_regs(task)); else retval = task_user_gs(task); } return retval; } static int set_segment_reg(struct task_struct *task, unsigned long offset, u16 value) { /* * The value argument was already truncated to 16 bits. */ if (invalid_selector(value)) return -EIO; /* * For %cs and %ss we cannot permit a null selector. * We can permit a bogus selector as long as it has USER_RPL. * Null selectors are fine for other segment registers, but * we will never get back to user mode with invalid %cs or %ss * and will take the trap in iret instead. Much code relies * on user_mode() to distinguish a user trap frame (which can * safely use invalid selectors) from a kernel trap frame. */ switch (offset) { case offsetof(struct user_regs_struct, cs): case offsetof(struct user_regs_struct, ss): if (unlikely(value == 0)) return -EIO; default: *pt_regs_access(task_pt_regs(task), offset) = value; break; case offsetof(struct user_regs_struct, gs): if (task == current) set_user_gs(task_pt_regs(task), value); else task_user_gs(task) = value; } return 0; } #else /* CONFIG_X86_64 */ #define FLAG_MASK (FLAG_MASK_32 | X86_EFLAGS_NT) static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset) { BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0); return ®s->r15 + (offset / sizeof(regs->r15)); } static u16 get_segment_reg(struct task_struct *task, unsigned long offset) { /* * Returning the value truncates it to 16 bits. */ unsigned int seg; switch (offset) { case offsetof(struct user_regs_struct, fs): if (task == current) { /* Older gas can't assemble movq %?s,%r?? */ asm("movl %%fs,%0" : "=r" (seg)); return seg; } return task->thread.fsindex; case offsetof(struct user_regs_struct, gs): if (task == current) { asm("movl %%gs,%0" : "=r" (seg)); return seg; } return task->thread.gsindex; case offsetof(struct user_regs_struct, ds): if (task == current) { asm("movl %%ds,%0" : "=r" (seg)); return seg; } return task->thread.ds; case offsetof(struct user_regs_struct, es): if (task == current) { asm("movl %%es,%0" : "=r" (seg)); return seg; } return task->thread.es; case offsetof(struct user_regs_struct, cs): case offsetof(struct user_regs_struct, ss): break; } return *pt_regs_access(task_pt_regs(task), offset); } static int set_segment_reg(struct task_struct *task, unsigned long offset, u16 value) { /* * The value argument was already truncated to 16 bits. */ if (invalid_selector(value)) return -EIO; switch (offset) { case offsetof(struct user_regs_struct,fs): /* * If this is setting fs as for normal 64-bit use but * setting fs_base has implicitly changed it, leave it. */ if ((value == FS_TLS_SEL && task->thread.fsindex == 0 && task->thread.fs != 0) || (value == 0 && task->thread.fsindex == FS_TLS_SEL && task->thread.fs == 0)) break; task->thread.fsindex = value; if (task == current) loadsegment(fs, task->thread.fsindex); break; case offsetof(struct user_regs_struct,gs): /* * If this is setting gs as for normal 64-bit use but * setting gs_base has implicitly changed it, leave it. */ if ((value == GS_TLS_SEL && task->thread.gsindex == 0 && task->thread.gs != 0) || (value == 0 && task->thread.gsindex == GS_TLS_SEL && task->thread.gs == 0)) break; task->thread.gsindex = value; if (task == current) load_gs_index(task->thread.gsindex); break; case offsetof(struct user_regs_struct,ds): task->thread.ds = value; if (task == current) loadsegment(ds, task->thread.ds); break; case offsetof(struct user_regs_struct,es): task->thread.es = value; if (task == current) loadsegment(es, task->thread.es); break; /* * Can't actually change these in 64-bit mode. */ case offsetof(struct user_regs_struct,cs): if (unlikely(value == 0)) return -EIO; #ifdef CONFIG_IA32_EMULATION if (test_tsk_thread_flag(task, TIF_IA32)) task_pt_regs(task)->cs = value; #endif break; case offsetof(struct user_regs_struct,ss): if (unlikely(value == 0)) return -EIO; #ifdef CONFIG_IA32_EMULATION if (test_tsk_thread_flag(task, TIF_IA32)) task_pt_regs(task)->ss = value; #endif break; } return 0; } #endif /* CONFIG_X86_32 */ static unsigned long get_flags(struct task_struct *task) { unsigned long retval = task_pt_regs(task)->flags; /* * If the debugger set TF, hide it from the readout. */ if (test_tsk_thread_flag(task, TIF_FORCED_TF)) retval &= ~X86_EFLAGS_TF; return retval; } static int set_flags(struct task_struct *task, unsigned long value) { struct pt_regs *regs = task_pt_regs(task); /* * If the user value contains TF, mark that * it was not "us" (the debugger) that set it. * If not, make sure it stays set if we had. */ if (value & X86_EFLAGS_TF) clear_tsk_thread_flag(task, TIF_FORCED_TF); else if (test_tsk_thread_flag(task, TIF_FORCED_TF)) value |= X86_EFLAGS_TF; regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK); return 0; } static int putreg(struct task_struct *child, unsigned long offset, unsigned long value) { switch (offset) { case offsetof(struct user_regs_struct, cs): case offsetof(struct user_regs_struct, ds): case offsetof(struct user_regs_struct, es): case offsetof(struct user_regs_struct, fs): case offsetof(struct user_regs_struct, gs): case offsetof(struct user_regs_struct, ss): return set_segment_reg(child, offset, value); case offsetof(struct user_regs_struct, flags): return set_flags(child, value); #ifdef CONFIG_X86_64 case offsetof(struct user_regs_struct,fs_base): if (value >= TASK_SIZE_OF(child)) return -EIO; /* * When changing the segment base, use do_arch_prctl * to set either thread.fs or thread.fsindex and the * corresponding GDT slot. */ if (child->thread.fs != value) return do_arch_prctl(child, ARCH_SET_FS, value); return 0; case offsetof(struct user_regs_struct,gs_base): /* * Exactly the same here as the %fs handling above. */ if (value >= TASK_SIZE_OF(child)) return -EIO; if (child->thread.gs != value) return do_arch_prctl(child, ARCH_SET_GS, value); return 0; #endif } *pt_regs_access(task_pt_regs(child), offset) = value; return 0; } static unsigned long getreg(struct task_struct *task, unsigned long offset) { switch (offset) { case offsetof(struct user_regs_struct, cs): case offsetof(struct user_regs_struct, ds): case offsetof(struct user_regs_struct, es): case offsetof(struct user_regs_struct, fs): case offsetof(struct user_regs_struct, gs): case offsetof(struct user_regs_struct, ss): return get_segment_reg(task, offset); case offsetof(struct user_regs_struct, flags): return get_flags(task); #ifdef CONFIG_X86_64 case offsetof(struct user_regs_struct, fs_base): { /* * do_arch_prctl may have used a GDT slot instead of * the MSR. To userland, it appears the same either * way, except the %fs segment selector might not be 0. */ unsigned int seg = task->thread.fsindex; if (task->thread.fs != 0) return task->thread.fs; if (task == current) asm("movl %%fs,%0" : "=r" (seg)); if (seg != FS_TLS_SEL) return 0; return get_desc_base(&task->thread.tls_array[FS_TLS]); } case offsetof(struct user_regs_struct, gs_base): { /* * Exactly the same here as the %fs handling above. */ unsigned int seg = task->thread.gsindex; if (task->thread.gs != 0) return task->thread.gs; if (task == current) asm("movl %%gs,%0" : "=r" (seg)); if (seg != GS_TLS_SEL) return 0; return get_desc_base(&task->thread.tls_array[GS_TLS]); } #endif } return *pt_regs_access(task_pt_regs(task), offset); } static int genregs_get(struct task_struct *target, const struct user_regset *regset, unsigned int pos, unsigned int count, void *kbuf, void __user *ubuf) { if (kbuf) { unsigned long *k = kbuf; while (count >= sizeof(*k)) { *k++ = getreg(target, pos); count -= sizeof(*k); pos += sizeof(*k); } } else { unsigned long __user *u = ubuf; while (count >= sizeof(*u)) { if (__put_user(getreg(target, pos), u++)) return -EFAULT; count -= sizeof(*u); pos += sizeof(*u); } } return 0; } 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) { int ret = 0; if (kbuf) { const unsigned long *k = kbuf; while (count >= sizeof(*k) && !ret) { ret = putreg(target, pos, *k++); count -= sizeof(*k); pos += sizeof(*k); } } else { const unsigned long __user *u = ubuf; while (count >= sizeof(*u) && !ret) { unsigned long word; ret = __get_user(word, u++); if (ret) break; ret = putreg(target, pos, word); count -= sizeof(*u); pos += sizeof(*u); } } return ret; } static void ptrace_triggered(struct perf_event *bp, int nmi, struct perf_sample_data *data, struct pt_regs *regs) { int i; struct thread_struct *thread = &(current->thread); /* * Store in the virtual DR6 register the fact that the breakpoint * was hit so the thread's debugger will see it. */ for (i = 0; i < HBP_NUM; i++) { if (thread->ptrace_bps[i] == bp) break; } thread->debugreg6 |= (DR_TRAP0 << i); } /* * Walk through every ptrace breakpoints for this thread and * build the dr7 value on top of their attributes. * */ static unsigned long ptrace_get_dr7(struct perf_event *bp[]) { int i; int dr7 = 0; struct arch_hw_breakpoint *info; for (i = 0; i < HBP_NUM; i++) { if (bp[i] && !bp[i]->attr.disabled) { info = counter_arch_bp(bp[i]); dr7 |= encode_dr7(i, info->len, info->type); } } return dr7; } static int ptrace_modify_breakpoint(struct perf_event *bp, int len, int type, struct task_struct *tsk, int disabled) { int err; int gen_len, gen_type; struct perf_event_attr attr; /* * We shoud have at least an inactive breakpoint at this * slot. It means the user is writing dr7 without having * written the address register first */ if (!bp) return -EINVAL; err = arch_bp_generic_fields(len, type, &gen_len, &gen_type); if (err) return err; attr = bp->attr; attr.bp_len = gen_len; attr.bp_type = gen_type; attr.disabled = disabled; return modify_user_hw_breakpoint(bp, &attr); } /* * Handle ptrace writes to debug register 7. */ static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data) { struct thread_struct *thread = &(tsk->thread); unsigned long old_dr7; int i, orig_ret = 0, rc = 0; int enabled, second_pass = 0; unsigned len, type; struct perf_event *bp; data &= ~DR_CONTROL_RESERVED; old_dr7 = ptrace_get_dr7(thread->ptrace_bps); restore: /* * Loop through all the hardware breakpoints, making the * appropriate changes to each. */ for (i = 0; i < HBP_NUM; i++) { enabled = decode_dr7(data, i, &len, &type); bp = thread->ptrace_bps[i]; if (!enabled) { if (bp) { /* * Don't unregister the breakpoints right-away, * unless all register_user_hw_breakpoint() * requests have succeeded. This prevents * any window of opportunity for debug * register grabbing by other users. */ if (!second_pass) continue; rc = ptrace_modify_breakpoint(bp, len, type, tsk, 1); if (rc) break; } continue; } rc = ptrace_modify_breakpoint(bp, len, type, tsk, 0); if (rc) break; } /* * Make a second pass to free the remaining unused breakpoints * or to restore the original breakpoints if an error occurred. */ if (!second_pass) { second_pass = 1; if (rc < 0) { orig_ret = rc; data = old_dr7; } goto restore; } return ((orig_ret < 0) ? orig_ret : rc); } /* * Handle PTRACE_PEEKUSR calls for the debug register area. */ static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n) { struct thread_struct *thread = &(tsk->thread); unsigned long val = 0; if (n < HBP_NUM) { struct perf_event *bp; bp = thread->ptrace_bps[n]; if (!bp) return 0; val = bp->hw.info.address; } else if (n == 6) { val = thread->debugreg6; } else if (n == 7) { val = ptrace_get_dr7(thread->ptrace_bps); } return val; } static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr, unsigned long addr) { struct perf_event *bp; struct thread_struct *t = &tsk->thread; struct perf_event_attr attr; if (!t->ptrace_bps[nr]) { hw_breakpoint_init(&attr); /* * Put stub len and type to register (reserve) an inactive but * correct bp */ attr.bp_addr = addr; attr.bp_len = HW_BREAKPOINT_LEN_1; attr.bp_type = HW_BREAKPOINT_W; attr.disabled = 1; bp = register_user_hw_breakpoint(&attr, ptrace_triggered, tsk); /* * CHECKME: the previous code returned -EIO if the addr wasn't * a valid task virtual addr. The new one will return -EINVAL in * this case. * -EINVAL may be what we want for in-kernel breakpoints users, * but -EIO looks better for ptrace, since we refuse a register * writing for the user. And anyway this is the previous * behaviour. */ if (IS_ERR(bp)) return PTR_ERR(bp); t->ptrace_bps[nr] = bp; } else { int err; bp = t->ptrace_bps[nr]; attr = bp->attr; attr.bp_addr = addr; err = modify_user_hw_breakpoint(bp, &attr); if (err) return err; } return 0; } /* * Handle PTRACE_POKEUSR calls for the debug register area. */ int ptrace_set_debugreg(struct task_struct *tsk, int n, unsigned long val) { struct thread_struct *thread = &(tsk->thread); int rc = 0; /* There are no DR4 or DR5 registers */ if (n == 4 || n == 5) return -EIO; if (n == 6) { thread->debugreg6 = val; goto ret_path; } if (n < HBP_NUM) { rc = ptrace_set_breakpoint_addr(tsk, n, val); if (rc) return rc; } /* All that's left is DR7 */ if (n == 7) rc = ptrace_write_dr7(tsk, val); ret_path: return rc; } /* * These access the current or another (stopped) task's io permission * bitmap for debugging or core dump. */ static int ioperm_active(struct task_struct *target, const struct user_regset *regset) { return target->thread.io_bitmap_max / regset->size; } static int ioperm_get(struct task_struct *target, const struct user_regset *regset, unsigned int pos, unsigned int count, void *kbuf, void __user *ubuf) { if (!target->thread.io_bitmap_ptr) return -ENXIO; return user_regset_copyout(&pos, &count, &kbuf, &ubuf, target->thread.io_bitmap_ptr, 0, IO_BITMAP_BYTES); } #ifdef CONFIG_X86_PTRACE_BTS /* * A branch trace store context. * * Contexts may only be installed by ptrace_bts_config() and only for * ptraced tasks. * * Contexts are destroyed when the tracee is detached from the tracer. * The actual destruction work requires interrupts enabled, so the * work is deferred and will be scheduled during __ptrace_unlink(). * * Contexts hold an additional task_struct reference on the traced * task, as well as a reference on the tracer's mm. * * Ptrace already holds a task_struct for the duration of ptrace operations, * but since destruction is deferred, it may be executed after both * tracer and tracee exited. */ struct bts_context { /* The branch trace handle. */ struct bts_tracer *tracer; /* The buffer used to store the branch trace and its size. */ void *buffer; unsigned int size; /* The mm that paid for the above buffer. */ struct mm_struct *mm; /* The task this context belongs to. */ struct task_struct *task; /* The signal to send on a bts buffer overflow. */ unsigned int bts_ovfl_signal; /* The work struct to destroy a context. */ struct work_struct work; }; static int alloc_bts_buffer(struct bts_context *context, unsigned int size) { void *buffer = NULL; int err = -ENOMEM; err = account_locked_memory(current->mm, current->signal->rlim, size); if (err < 0) return err; buffer = kzalloc(size, GFP_KERNEL); if (!buffer) goto out_refund; context->buffer = buffer; context->size = size; context->mm = get_task_mm(current); return 0; out_refund: refund_locked_memory(current->mm, size); return err; } static inline void free_bts_buffer(struct bts_context *context) { if (!context->buffer) return; kfree(context->buffer); context->buffer = NULL; refund_locked_memory(context->mm, context->size); context->size = 0; mmput(context->mm); context->mm = NULL; } static void free_bts_context_work(struct work_struct *w) { struct bts_context *context; context = container_of(w, struct bts_context, work); ds_release_bts(context->tracer); put_task_struct(context->task); free_bts_buffer(context); kfree(context); } static inline void free_bts_context(struct bts_context *context) { INIT_WORK(&context->work, free_bts_context_work); schedule_work(&context->work); } static inline struct bts_context *alloc_bts_context(struct task_struct *task) { struct bts_context *context = kzalloc(sizeof(*context), GFP_KERNEL); if (context) { context->task = task; task->bts = context; get_task_struct(task); } return context; } static int ptrace_bts_read_record(struct task_struct *child, size_t index, struct bts_struct __user *out) { struct bts_context *context; const struct bts_trace *trace; struct bts_struct bts; const unsigned char *at; int error; context = child->bts; if (!context) return -ESRCH; trace = ds_read_bts(context->tracer); if (!trace) return -ESRCH; at = trace->ds.top - ((index + 1) * trace->ds.size); if ((void *)at < trace->ds.begin) at += (trace->ds.n * trace->ds.size); if (!trace->read) return -EOPNOTSUPP; error = trace->read(context->tracer, at, &bts); if (error < 0) return error; if (copy_to_user(out, &bts, sizeof(bts))) return -EFAULT; return sizeof(bts); } static int ptrace_bts_drain(struct task_struct *child, long size, struct bts_struct __user *out) { struct bts_context *context; const struct bts_trace *trace; const unsigned char *at; int error, drained = 0; context = child->bts; if (!context) return -ESRCH; trace = ds_read_bts(context->tracer); if (!trace) return -ESRCH; if (!trace->read) return -EOPNOTSUPP; if (size < (trace->ds.top - trace->ds.begin)) return -EIO; for (at = trace->ds.begin; (void *)at < trace->ds.top; out++, drained++, at += trace->ds.size) { struct bts_struct bts; error = trace->read(context->tracer, at, &bts); if (error < 0) return error; if (copy_to_user(out, &bts, sizeof(bts))) return -EFAULT; } memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size); error = ds_reset_bts(context->tracer); if (error < 0) return error; return drained; } static int ptrace_bts_config(struct task_struct *child, long cfg_size, const struct ptrace_bts_config __user *ucfg) { struct bts_context *context; struct ptrace_bts_config cfg; unsigned int flags = 0; if (cfg_size < sizeof(cfg)) return -EIO; if (copy_from_user(&cfg, ucfg, sizeof(cfg))) return -EFAULT; context = child->bts; if (!context) context = alloc_bts_context(child); if (!context) return -ENOMEM; if (cfg.flags & PTRACE_BTS_O_SIGNAL) { if (!cfg.signal) return -EINVAL; return -EOPNOTSUPP; context->bts_ovfl_signal = cfg.signal; } ds_release_bts(context->tracer); context->tracer = NULL; if ((cfg.flags & PTRACE_BTS_O_ALLOC) && (cfg.size != context->size)) { int err; free_bts_buffer(context); if (!cfg.size) return 0; err = alloc_bts_buffer(context, cfg.size); if (err < 0) return err; } if (cfg.flags & PTRACE_BTS_O_TRACE) flags |= BTS_USER; if (cfg.flags & PTRACE_BTS_O_SCHED) flags |= BTS_TIMESTAMPS; context->tracer = ds_request_bts_task(child, context->buffer, context->size, NULL, (size_t)-1, flags); if (unlikely(IS_ERR(context->tracer))) { int error = PTR_ERR(context->tracer); free_bts_buffer(context); context->tracer = NULL; return error; } return sizeof(cfg); } static int ptrace_bts_status(struct task_struct *child, long cfg_size, struct ptrace_bts_config __user *ucfg) { struct bts_context *context; const struct bts_trace *trace; struct ptrace_bts_config cfg; context = child->bts; if (!context) return -ESRCH; if (cfg_size < sizeof(cfg)) return -EIO; trace = ds_read_bts(context->tracer); if (!trace) return -ESRCH; memset(&cfg, 0, sizeof(cfg)); cfg.size = trace->ds.end - trace->ds.begin; cfg.signal = context->bts_ovfl_signal; cfg.bts_size = sizeof(struct bts_struct); if (cfg.signal) cfg.flags |= PTRACE_BTS_O_SIGNAL; if (trace->ds.flags & BTS_USER) cfg.flags |= PTRACE_BTS_O_TRACE; if (trace->ds.flags & BTS_TIMESTAMPS) cfg.flags |= PTRACE_BTS_O_SCHED; if (copy_to_user(ucfg, &cfg, sizeof(cfg))) return -EFAULT; return sizeof(cfg); } static int ptrace_bts_clear(struct task_struct *child) { struct bts_context *context; const struct bts_trace *trace; context = child->bts; if (!context) return -ESRCH; trace = ds_read_bts(context->tracer); if (!trace) return -ESRCH; memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size); return ds_reset_bts(context->tracer); } static int ptrace_bts_size(struct task_struct *child) { struct bts_context *context; const struct bts_trace *trace; context = child->bts; if (!context) return -ESRCH; trace = ds_read_bts(context->tracer); if (!trace) return -ESRCH; return (trace->ds.top - trace->ds.begin) / trace->ds.size; } /* * Called from __ptrace_unlink() after the child has been moved back * to its original parent. */ void ptrace_bts_untrace(struct task_struct *child) { if (unlikely(child->bts)) { free_bts_context(child->bts); child->bts = NULL; } } #endif /* CONFIG_X86_PTRACE_BTS */ /* * Called by kernel/ptrace.c when detaching.. * * Make sure the single step bit is not set. */ void ptrace_disable(struct task_struct *child) { user_disable_single_step(child); #ifdef TIF_SYSCALL_EMU clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); #endif } #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION static const struct user_regset_view user_x86_32_view; /* Initialized below. */ #endif long arch_ptrace(struct task_struct *child, long request, long addr, long data) { int ret; unsigned long __user *datap = (unsigned long __user *)data; switch (request) { /* read the word at location addr in the USER area. */ case PTRACE_PEEKUSR: { unsigned long tmp; ret = -EIO; if ((addr & (sizeof(data) - 1)) || addr < 0 || addr >= sizeof(struct user)) break; tmp = 0; /* Default return condition */ if (addr < sizeof(struct user_regs_struct)) tmp = getreg(child, addr); else if (addr >= offsetof(struct user, u_debugreg[0]) && addr <= offsetof(struct user, u_debugreg[7])) { addr -= offsetof(struct user, u_debugreg[0]); tmp = ptrace_get_debugreg(child, addr / sizeof(data)); } ret = put_user(tmp, datap); break; } case PTRACE_POKEUSR: /* write the word at location addr in the USER area */ ret = -EIO; if ((addr & (sizeof(data) - 1)) || addr < 0 || addr >= sizeof(struct user)) break; if (addr < sizeof(struct user_regs_struct)) ret = putreg(child, addr, data); else if (addr >= offsetof(struct user, u_debugreg[0]) && addr <= offsetof(struct user, u_debugreg[7])) { addr -= offsetof(struct user, u_debugreg[0]); ret = ptrace_set_debugreg(child, addr / sizeof(data), data); } break; case PTRACE_GETREGS: /* Get all gp regs from the child. */ return copy_regset_to_user(child, task_user_regset_view(current), REGSET_GENERAL, 0, sizeof(struct user_regs_struct), datap); case PTRACE_SETREGS: /* Set all gp regs in the child. */ return copy_regset_from_user(child, task_user_regset_view(current), REGSET_GENERAL, 0, sizeof(struct user_regs_struct), datap); case PTRACE_GETFPREGS: /* Get the child FPU state. */ return copy_regset_to_user(child, task_user_regset_view(current), REGSET_FP, 0, sizeof(struct user_i387_struct), datap); case PTRACE_SETFPREGS: /* Set the child FPU state. */ return copy_regset_from_user(child, task_user_regset_view(current), REGSET_FP, 0, sizeof(struct user_i387_struct), datap); #ifdef CONFIG_X86_32 case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */ return copy_regset_to_user(child, &user_x86_32_view, REGSET_XFP, 0, sizeof(struct user_fxsr_struct), datap) ? -EIO : 0; case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */ return copy_regset_from_user(child, &user_x86_32_view, REGSET_XFP, 0, sizeof(struct user_fxsr_struct), datap) ? -EIO : 0; #endif #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION case PTRACE_GET_THREAD_AREA: if (addr < 0) return -EIO; ret = do_get_thread_area(child, addr, (struct user_desc __user *) data); break; case PTRACE_SET_THREAD_AREA: if (addr < 0) return -EIO; ret = do_set_thread_area(child, addr, (struct user_desc __user *) data, 0); break; #endif #ifdef CONFIG_X86_64 /* normal 64bit interface to access TLS data. Works just like arch_prctl, except that the arguments are reversed. */ case PTRACE_ARCH_PRCTL: ret = do_arch_prctl(child, data, addr); break; #endif /* * These bits need more cooking - not enabled yet: */ #ifdef CONFIG_X86_PTRACE_BTS case PTRACE_BTS_CONFIG: ret = ptrace_bts_config (child, data, (struct ptrace_bts_config __user *)addr); break; case PTRACE_BTS_STATUS: ret = ptrace_bts_status (child, data, (struct ptrace_bts_config __user *)addr); break; case PTRACE_BTS_SIZE: ret = ptrace_bts_size(child); break; case PTRACE_BTS_GET: ret = ptrace_bts_read_record (child, data, (struct bts_struct __user *) addr); break; case PTRACE_BTS_CLEAR: ret = ptrace_bts_clear(child); break; case PTRACE_BTS_DRAIN: ret = ptrace_bts_drain (child, data, (struct bts_struct __user *) addr); break; #endif /* CONFIG_X86_PTRACE_BTS */ default: ret = ptrace_request(child, request, addr, data); break; } return ret; } #ifdef CONFIG_IA32_EMULATION #include #include #include #include #define R32(l,q) \ case offsetof(struct user32, regs.l): \ regs->q = value; break #define SEG32(rs) \ case offsetof(struct user32, regs.rs): \ return set_segment_reg(child, \ offsetof(struct user_regs_struct, rs), \ value); \ break static int putreg32(struct task_struct *child, unsigned regno, u32 value) { struct pt_regs *regs = task_pt_regs(child); switch (regno) { SEG32(cs); SEG32(ds); SEG32(es); SEG32(fs); SEG32(gs); SEG32(ss); R32(ebx, bx); R32(ecx, cx); R32(edx, dx); R32(edi, di); R32(esi, si); R32(ebp, bp); R32(eax, ax); R32(eip, ip); R32(esp, sp); case offsetof(struct user32, regs.orig_eax): /* * A 32-bit debugger setting orig_eax means to restore * the state of the task restarting a 32-bit syscall. * Make sure we interpret the -ERESTART* codes correctly * in case the task is not actually still sitting at the * exit from a 32-bit syscall with TS_COMPAT still set. */ regs->orig_ax = value; if (syscall_get_nr(child, regs) >= 0) task_thread_info(child)->status |= TS_COMPAT; break; case offsetof(struct user32, regs.eflags): return set_flags(child, value); case offsetof(struct user32, u_debugreg[0]) ... offsetof(struct user32, u_debugreg[7]): regno -= offsetof(struct user32, u_debugreg[0]); return ptrace_set_debugreg(child, regno / 4, value); default: if (regno > sizeof(struct user32) || (regno & 3)) return -EIO; /* * Other dummy fields in the virtual user structure * are ignored */ break; } return 0; } #undef R32 #undef SEG32 #define R32(l,q) \ case offsetof(struct user32, regs.l): \ *val = regs->q; break #define SEG32(rs) \ case offsetof(struct user32, regs.rs): \ *val = get_segment_reg(child, \ offsetof(struct user_regs_struct, rs)); \ break static int getreg32(struct task_struct *child, unsigned regno, u32 *val) { struct pt_regs *regs = task_pt_regs(child); switch (regno) { SEG32(ds); SEG32(es); SEG32(fs); SEG32(gs); R32(cs, cs); R32(ss, ss); R32(ebx, bx); R32(ecx, cx); R32(edx, dx); R32(edi, di); R32(esi, si); R32(ebp, bp); R32(eax, ax); R32(orig_eax, orig_ax); R32(eip, ip); R32(esp, sp); case offsetof(struct user32, regs.eflags): *val = get_flags(child); break; case offsetof(struct user32, u_debugreg[0]) ... offsetof(struct user32, u_debugreg[7]): regno -= offsetof(struct user32, u_debugreg[0]); *val = ptrace_get_debugreg(child, regno / 4); break; default: if (regno > sizeof(struct user32) || (regno & 3)) return -EIO; /* * Other dummy fields in the virtual user structure * are ignored */ *val = 0; break; } return 0; } #undef R32 #undef SEG32 static int genregs32_get(struct task_struct *target, const struct user_regset *regset, unsigned int pos, unsigned int count, void *kbuf, void __user *ubuf) { if (kbuf) { compat_ulong_t *k = kbuf; while (count >= sizeof(*k)) { getreg32(target, pos, k++); count -= sizeof(*k); pos += sizeof(*k); } } else { compat_ulong_t __user *u = ubuf; while (count >= sizeof(*u)) { compat_ulong_t word; getreg32(target, pos, &word); if (__put_user(word, u++)) return -EFAULT; count -= sizeof(*u); pos += sizeof(*u); } } return 0; } static int genregs32_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 = 0; if (kbuf) { const compat_ulong_t *k = kbuf; while (count >= sizeof(*k) && !ret) { ret = putreg32(target, pos, *k++); count -= sizeof(*k); pos += sizeof(*k); } } else { const compat_ulong_t __user *u = ubuf; while (count >= sizeof(*u) && !ret) { compat_ulong_t word; ret = __get_user(word, u++); if (ret) break; ret = putreg32(target, pos, word); count -= sizeof(*u); pos += sizeof(*u); } } return ret; } long compat_arch_ptrace(struct task_struct *child, compat_long_t request, compat_ulong_t caddr, compat_ulong_t cdata) { unsigned long addr = caddr; unsigned long data = cdata; void __user *datap = compat_ptr(data); int ret; __u32 val; switch (request) { case PTRACE_PEEKUSR: ret = getreg32(child, addr, &val); if (ret == 0) ret = put_user(val, (__u32 __user *)datap); break; case PTRACE_POKEUSR: ret = putreg32(child, addr, data); break; case PTRACE_GETREGS: /* Get all gp regs from the child. */ return copy_regset_to_user(child, &user_x86_32_view, REGSET_GENERAL, 0, sizeof(struct user_regs_struct32), datap); case PTRACE_SETREGS: /* Set all gp regs in the child. */ return copy_regset_from_user(child, &user_x86_32_view, REGSET_GENERAL, 0, sizeof(struct user_regs_struct32), datap); case PTRACE_GETFPREGS: /* Get the child FPU state. */ return copy_regset_to_user(child, &user_x86_32_view, REGSET_FP, 0, sizeof(struct user_i387_ia32_struct), datap); case PTRACE_SETFPREGS: /* Set the child FPU state. */ return copy_regset_from_user( child, &user_x86_32_view, REGSET_FP, 0, sizeof(struct user_i387_ia32_struct), datap); case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */ return copy_regset_to_user(child, &user_x86_32_view, REGSET_XFP, 0, sizeof(struct user32_fxsr_struct), datap); case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */ return copy_regset_from_user(child, &user_x86_32_view, REGSET_XFP, 0, sizeof(struct user32_fxsr_struct), datap); case PTRACE_GET_THREAD_AREA: case PTRACE_SET_THREAD_AREA: #ifdef CONFIG_X86_PTRACE_BTS case PTRACE_BTS_CONFIG: case PTRACE_BTS_STATUS: case PTRACE_BTS_SIZE: case PTRACE_BTS_GET: case PTRACE_BTS_CLEAR: case PTRACE_BTS_DRAIN: #endif /* CONFIG_X86_PTRACE_BTS */ return arch_ptrace(child, request, addr, data); default: return compat_ptrace_request(child, request, addr, data); } return ret; } #endif /* CONFIG_IA32_EMULATION */ #ifdef CONFIG_X86_64 static struct user_regset x86_64_regsets[] __read_mostly = { [REGSET_GENERAL] = { .core_note_type = NT_PRSTATUS, .n = sizeof(struct user_regs_struct) / sizeof(long), .size = sizeof(long), .align = sizeof(long), .get = genregs_get, .set = genregs_set }, [REGSET_FP] = { .core_note_type = NT_PRFPREG, .n = sizeof(struct user_i387_struct) / sizeof(long), .size = sizeof(long), .align = sizeof(long), .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set }, [REGSET_XSTATE] = { .core_note_type = NT_X86_XSTATE, .size = sizeof(u64), .align = sizeof(u64), .active = xstateregs_active, .get = xstateregs_get, .set = xstateregs_set }, [REGSET_IOPERM64] = { .core_note_type = NT_386_IOPERM, .n = IO_BITMAP_LONGS, .size = sizeof(long), .align = sizeof(long), .active = ioperm_active, .get = ioperm_get }, }; static const struct user_regset_view user_x86_64_view = { .name = "x86_64", .e_machine = EM_X86_64, .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets) }; #else /* CONFIG_X86_32 */ #define user_regs_struct32 user_regs_struct #define genregs32_get genregs_get #define genregs32_set genregs_set #define user_i387_ia32_struct user_i387_struct #define user32_fxsr_struct user_fxsr_struct #endif /* CONFIG_X86_64 */ #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION static struct user_regset x86_32_regsets[] __read_mostly = { [REGSET_GENERAL] = { .core_note_type = NT_PRSTATUS, .n = sizeof(struct user_regs_struct32) / sizeof(u32), .size = sizeof(u32), .align = sizeof(u32), .get = genregs32_get, .set = genregs32_set }, [REGSET_FP] = { .core_note_type = NT_PRFPREG, .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32), .size = sizeof(u32), .align = sizeof(u32), .active = fpregs_active, .get = fpregs_get, .set = fpregs_set }, [REGSET_XFP] = { .core_note_type = NT_PRXFPREG, .n = sizeof(struct user32_fxsr_struct) / sizeof(u32), .size = sizeof(u32), .align = sizeof(u32), .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set }, [REGSET_XSTATE] = { .core_note_type = NT_X86_XSTATE, .size = sizeof(u64), .align = sizeof(u64), .active = xstateregs_active, .get = xstateregs_get, .set = xstateregs_set }, [REGSET_TLS] = { .core_note_type = NT_386_TLS, .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN, .size = sizeof(struct user_desc), .align = sizeof(struct user_desc), .active = regset_tls_active, .get = regset_tls_get, .set = regset_tls_set }, [REGSET_IOPERM32] = { .core_note_type = NT_386_IOPERM, .n = IO_BITMAP_BYTES / sizeof(u32), .size = sizeof(u32), .align = sizeof(u32), .active = ioperm_active, .get = ioperm_get }, }; static const struct user_regset_view user_x86_32_view = { .name = "i386", .e_machine = EM_386, .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets) }; #endif /* * This represents bytes 464..511 in the memory layout exported through * the REGSET_XSTATE interface. */ u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS]; void update_regset_xstate_info(unsigned int size, u64 xstate_mask) { #ifdef CONFIG_X86_64 x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64); #endif #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64); #endif xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask; } const struct user_regset_view *task_user_regset_view(struct task_struct *task) { #ifdef CONFIG_IA32_EMULATION if (test_tsk_thread_flag(task, TIF_IA32)) #endif #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION return &user_x86_32_view; #endif #ifdef CONFIG_X86_64 return &user_x86_64_view; #endif } static void fill_sigtrap_info(struct task_struct *tsk, struct pt_regs *regs, int error_code, int si_code, struct siginfo *info) { tsk->thread.trap_no = 1; tsk->thread.error_code = error_code; memset(info, 0, sizeof(*info)); info->si_signo = SIGTRAP; info->si_code = si_code; info->si_addr = user_mode_vm(regs) ? (void __user *)regs->ip : NULL; } void user_single_step_siginfo(struct task_struct *tsk, struct pt_regs *regs, struct siginfo *info) { fill_sigtrap_info(tsk, regs, 0, TRAP_BRKPT, info); } void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code, int si_code) { struct siginfo info; fill_sigtrap_info(tsk, regs, error_code, si_code, &info); /* Send us the fake SIGTRAP */ force_sig_info(SIGTRAP, &info, tsk); } #ifdef CONFIG_X86_32 # define IS_IA32 1 #elif defined CONFIG_IA32_EMULATION # define IS_IA32 is_compat_task() #else # define IS_IA32 0 #endif /* * We must return the syscall number to actually look up in the table. * This can be -1L to skip running any syscall at all. */ asmregparm long syscall_trace_enter(struct pt_regs *regs) { long ret = 0; /* * If we stepped into a sysenter/syscall insn, it trapped in * kernel mode; do_debug() cleared TF and set TIF_SINGLESTEP. * If user-mode had set TF itself, then it's still clear from * do_debug() and we need to set it again to restore the user * state. If we entered on the slow path, TF was already set. */ if (test_thread_flag(TIF_SINGLESTEP)) regs->flags |= X86_EFLAGS_TF; /* do the secure computing check first */ secure_computing(regs->orig_ax); if (unlikely(test_thread_flag(TIF_SYSCALL_EMU))) ret = -1L; if ((ret || test_thread_flag(TIF_SYSCALL_TRACE)) && tracehook_report_syscall_entry(regs)) ret = -1L; if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) trace_sys_enter(regs, regs->orig_ax); if (unlikely(current->audit_context)) { if (IS_IA32) audit_syscall_entry(AUDIT_ARCH_I386, regs->orig_ax, regs->bx, regs->cx, regs->dx, regs->si); #ifdef CONFIG_X86_64 else audit_syscall_entry(AUDIT_ARCH_X86_64, regs->orig_ax, regs->di, regs->si, regs->dx, regs->r10); #endif } return ret ?: regs->orig_ax; } asmregparm void syscall_trace_leave(struct pt_regs *regs) { bool step; if (unlikely(current->audit_context)) audit_syscall_exit(AUDITSC_RESULT(regs->ax), regs->ax); if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) trace_sys_exit(regs, regs->ax); /* * If TIF_SYSCALL_EMU is set, we only get here because of * TIF_SINGLESTEP (i.e. this is PTRACE_SYSEMU_SINGLESTEP). * We already reported this syscall instruction in * syscall_trace_enter(). */ step = unlikely(test_thread_flag(TIF_SINGLESTEP)) && !test_thread_flag(TIF_SYSCALL_EMU); if (step || test_thread_flag(TIF_SYSCALL_TRACE)) tracehook_report_syscall_exit(regs, step); }