diff options
Diffstat (limited to 'arch/arm/kernel/ptrace.c')
-rw-r--r-- | arch/arm/kernel/ptrace.c | 935 |
1 files changed, 935 insertions, 0 deletions
diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c new file mode 100644 index 000000000..2771e6822 --- /dev/null +++ b/arch/arm/kernel/ptrace.c @@ -0,0 +1,935 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * linux/arch/arm/kernel/ptrace.c + * + * By Ross Biro 1/23/92 + * edited by Linus Torvalds + * ARM modifications Copyright (C) 2000 Russell King + */ +#include <linux/kernel.h> +#include <linux/sched/signal.h> +#include <linux/sched/task_stack.h> +#include <linux/mm.h> +#include <linux/elf.h> +#include <linux/smp.h> +#include <linux/ptrace.h> +#include <linux/user.h> +#include <linux/security.h> +#include <linux/init.h> +#include <linux/signal.h> +#include <linux/uaccess.h> +#include <linux/perf_event.h> +#include <linux/hw_breakpoint.h> +#include <linux/regset.h> +#include <linux/audit.h> +#include <linux/tracehook.h> +#include <linux/unistd.h> + +#include <asm/traps.h> + +#define CREATE_TRACE_POINTS +#include <trace/events/syscalls.h> + +#define REG_PC 15 +#define REG_PSR 16 +/* + * does not yet catch signals sent when the child dies. + * in exit.c or in signal.c. + */ + +#if 0 +/* + * Breakpoint SWI instruction: SWI &9F0001 + */ +#define BREAKINST_ARM 0xef9f0001 +#define BREAKINST_THUMB 0xdf00 /* fill this in later */ +#else +/* + * New breakpoints - use an undefined instruction. The ARM architecture + * reference manual guarantees that the following instruction space + * will produce an undefined instruction exception on all CPUs: + * + * ARM: xxxx 0111 1111 xxxx xxxx xxxx 1111 xxxx + * Thumb: 1101 1110 xxxx xxxx + */ +#define BREAKINST_ARM 0xe7f001f0 +#define BREAKINST_THUMB 0xde01 +#endif + +struct pt_regs_offset { + const char *name; + int offset; +}; + +#define REG_OFFSET_NAME(r) \ + {.name = #r, .offset = offsetof(struct pt_regs, ARM_##r)} +#define REG_OFFSET_END {.name = NULL, .offset = 0} + +static const struct pt_regs_offset regoffset_table[] = { + REG_OFFSET_NAME(r0), + REG_OFFSET_NAME(r1), + REG_OFFSET_NAME(r2), + REG_OFFSET_NAME(r3), + REG_OFFSET_NAME(r4), + REG_OFFSET_NAME(r5), + REG_OFFSET_NAME(r6), + REG_OFFSET_NAME(r7), + REG_OFFSET_NAME(r8), + REG_OFFSET_NAME(r9), + REG_OFFSET_NAME(r10), + REG_OFFSET_NAME(fp), + REG_OFFSET_NAME(ip), + REG_OFFSET_NAME(sp), + REG_OFFSET_NAME(lr), + REG_OFFSET_NAME(pc), + REG_OFFSET_NAME(cpsr), + REG_OFFSET_NAME(ORIG_r0), + 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; +} + +/** + * regs_within_kernel_stack() - check the address in the stack + * @regs: pt_regs which contains kernel stack pointer. + * @addr: address which is checked. + * + * regs_within_kernel_stack() checks @addr is within the kernel stack page(s). + * If @addr is within the kernel stack, it returns true. If not, returns false. + */ +bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr) +{ + return ((addr & ~(THREAD_SIZE - 1)) == + (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))); +} + +/** + * regs_get_kernel_stack_nth() - get Nth entry of the stack + * @regs: pt_regs which contains kernel stack pointer. + * @n: stack entry number. + * + * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which + * is specified by @regs. If the @n th entry is NOT in the kernel stack, + * this returns 0. + */ +unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n) +{ + unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs); + addr += n; + if (regs_within_kernel_stack(regs, (unsigned long)addr)) + return *addr; + else + return 0; +} + +/* + * this routine will get a word off of the processes privileged stack. + * the offset is how far from the base addr as stored in the THREAD. + * this routine assumes that all the privileged stacks are in our + * data space. + */ +static inline long get_user_reg(struct task_struct *task, int offset) +{ + return task_pt_regs(task)->uregs[offset]; +} + +/* + * this routine will put a word on the processes privileged stack. + * the offset is how far from the base addr as stored in the THREAD. + * this routine assumes that all the privileged stacks are in our + * data space. + */ +static inline int +put_user_reg(struct task_struct *task, int offset, long data) +{ + struct pt_regs newregs, *regs = task_pt_regs(task); + int ret = -EINVAL; + + newregs = *regs; + newregs.uregs[offset] = data; + + if (valid_user_regs(&newregs)) { + regs->uregs[offset] = data; + ret = 0; + } + + return ret; +} + +/* + * Called by kernel/ptrace.c when detaching.. + */ +void ptrace_disable(struct task_struct *child) +{ + /* Nothing to do. */ +} + +/* + * Handle hitting a breakpoint. + */ +void ptrace_break(struct pt_regs *regs) +{ + force_sig_fault(SIGTRAP, TRAP_BRKPT, + (void __user *)instruction_pointer(regs)); +} + +static int break_trap(struct pt_regs *regs, unsigned int instr) +{ + ptrace_break(regs); + return 0; +} + +static struct undef_hook arm_break_hook = { + .instr_mask = 0x0fffffff, + .instr_val = 0x07f001f0, + .cpsr_mask = PSR_T_BIT, + .cpsr_val = 0, + .fn = break_trap, +}; + +static struct undef_hook thumb_break_hook = { + .instr_mask = 0xffffffff, + .instr_val = 0x0000de01, + .cpsr_mask = PSR_T_BIT, + .cpsr_val = PSR_T_BIT, + .fn = break_trap, +}; + +static struct undef_hook thumb2_break_hook = { + .instr_mask = 0xffffffff, + .instr_val = 0xf7f0a000, + .cpsr_mask = PSR_T_BIT, + .cpsr_val = PSR_T_BIT, + .fn = break_trap, +}; + +static int __init ptrace_break_init(void) +{ + register_undef_hook(&arm_break_hook); + register_undef_hook(&thumb_break_hook); + register_undef_hook(&thumb2_break_hook); + return 0; +} + +core_initcall(ptrace_break_init); + +/* + * Read the word at offset "off" into the "struct user". We + * actually access the pt_regs stored on the kernel stack. + */ +static int ptrace_read_user(struct task_struct *tsk, unsigned long off, + unsigned long __user *ret) +{ + unsigned long tmp; + + if (off & 3) + return -EIO; + + tmp = 0; + if (off == PT_TEXT_ADDR) + tmp = tsk->mm->start_code; + else if (off == PT_DATA_ADDR) + tmp = tsk->mm->start_data; + else if (off == PT_TEXT_END_ADDR) + tmp = tsk->mm->end_code; + else if (off < sizeof(struct pt_regs)) + tmp = get_user_reg(tsk, off >> 2); + else if (off >= sizeof(struct user)) + return -EIO; + + return put_user(tmp, ret); +} + +/* + * Write the word at offset "off" into "struct user". We + * actually access the pt_regs stored on the kernel stack. + */ +static int ptrace_write_user(struct task_struct *tsk, unsigned long off, + unsigned long val) +{ + if (off & 3 || off >= sizeof(struct user)) + return -EIO; + + if (off >= sizeof(struct pt_regs)) + return 0; + + return put_user_reg(tsk, off >> 2, val); +} + +#ifdef CONFIG_IWMMXT + +/* + * Get the child iWMMXt state. + */ +static int ptrace_getwmmxregs(struct task_struct *tsk, void __user *ufp) +{ + struct thread_info *thread = task_thread_info(tsk); + + if (!test_ti_thread_flag(thread, TIF_USING_IWMMXT)) + return -ENODATA; + iwmmxt_task_disable(thread); /* force it to ram */ + return copy_to_user(ufp, &thread->fpstate.iwmmxt, IWMMXT_SIZE) + ? -EFAULT : 0; +} + +/* + * Set the child iWMMXt state. + */ +static int ptrace_setwmmxregs(struct task_struct *tsk, void __user *ufp) +{ + struct thread_info *thread = task_thread_info(tsk); + + if (!test_ti_thread_flag(thread, TIF_USING_IWMMXT)) + return -EACCES; + iwmmxt_task_release(thread); /* force a reload */ + return copy_from_user(&thread->fpstate.iwmmxt, ufp, IWMMXT_SIZE) + ? -EFAULT : 0; +} + +#endif + +#ifdef CONFIG_CRUNCH +/* + * Get the child Crunch state. + */ +static int ptrace_getcrunchregs(struct task_struct *tsk, void __user *ufp) +{ + struct thread_info *thread = task_thread_info(tsk); + + crunch_task_disable(thread); /* force it to ram */ + return copy_to_user(ufp, &thread->crunchstate, CRUNCH_SIZE) + ? -EFAULT : 0; +} + +/* + * Set the child Crunch state. + */ +static int ptrace_setcrunchregs(struct task_struct *tsk, void __user *ufp) +{ + struct thread_info *thread = task_thread_info(tsk); + + crunch_task_release(thread); /* force a reload */ + return copy_from_user(&thread->crunchstate, ufp, CRUNCH_SIZE) + ? -EFAULT : 0; +} +#endif + +#ifdef CONFIG_HAVE_HW_BREAKPOINT +/* + * Convert a virtual register number into an index for a thread_info + * breakpoint array. Breakpoints are identified using positive numbers + * whilst watchpoints are negative. The registers are laid out as pairs + * of (address, control), each pair mapping to a unique hw_breakpoint struct. + * Register 0 is reserved for describing resource information. + */ +static int ptrace_hbp_num_to_idx(long num) +{ + if (num < 0) + num = (ARM_MAX_BRP << 1) - num; + return (num - 1) >> 1; +} + +/* + * Returns the virtual register number for the address of the + * breakpoint at index idx. + */ +static long ptrace_hbp_idx_to_num(int idx) +{ + long mid = ARM_MAX_BRP << 1; + long num = (idx << 1) + 1; + return num > mid ? mid - num : num; +} + +/* + * Handle hitting a HW-breakpoint. + */ +static void ptrace_hbptriggered(struct perf_event *bp, + struct perf_sample_data *data, + struct pt_regs *regs) +{ + struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp); + long num; + int i; + + for (i = 0; i < ARM_MAX_HBP_SLOTS; ++i) + if (current->thread.debug.hbp[i] == bp) + break; + + num = (i == ARM_MAX_HBP_SLOTS) ? 0 : ptrace_hbp_idx_to_num(i); + + force_sig_ptrace_errno_trap((int)num, (void __user *)(bkpt->trigger)); +} + +/* + * Set ptrace breakpoint pointers to zero for this task. + * This is required in order to prevent child processes from unregistering + * breakpoints held by their parent. + */ +void clear_ptrace_hw_breakpoint(struct task_struct *tsk) +{ + memset(tsk->thread.debug.hbp, 0, sizeof(tsk->thread.debug.hbp)); +} + +/* + * Unregister breakpoints from this task and reset the pointers in + * the thread_struct. + */ +void flush_ptrace_hw_breakpoint(struct task_struct *tsk) +{ + int i; + struct thread_struct *t = &tsk->thread; + + for (i = 0; i < ARM_MAX_HBP_SLOTS; i++) { + if (t->debug.hbp[i]) { + unregister_hw_breakpoint(t->debug.hbp[i]); + t->debug.hbp[i] = NULL; + } + } +} + +static u32 ptrace_get_hbp_resource_info(void) +{ + u8 num_brps, num_wrps, debug_arch, wp_len; + u32 reg = 0; + + num_brps = hw_breakpoint_slots(TYPE_INST); + num_wrps = hw_breakpoint_slots(TYPE_DATA); + debug_arch = arch_get_debug_arch(); + wp_len = arch_get_max_wp_len(); + + reg |= debug_arch; + reg <<= 8; + reg |= wp_len; + reg <<= 8; + reg |= num_wrps; + reg <<= 8; + reg |= num_brps; + + return reg; +} + +static struct perf_event *ptrace_hbp_create(struct task_struct *tsk, int type) +{ + struct perf_event_attr attr; + + ptrace_breakpoint_init(&attr); + + /* Initialise fields to sane defaults. */ + attr.bp_addr = 0; + attr.bp_len = HW_BREAKPOINT_LEN_4; + attr.bp_type = type; + attr.disabled = 1; + + return register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL, + tsk); +} + +static int ptrace_gethbpregs(struct task_struct *tsk, long num, + unsigned long __user *data) +{ + u32 reg; + int idx, ret = 0; + struct perf_event *bp; + struct arch_hw_breakpoint_ctrl arch_ctrl; + + if (num == 0) { + reg = ptrace_get_hbp_resource_info(); + } else { + idx = ptrace_hbp_num_to_idx(num); + if (idx < 0 || idx >= ARM_MAX_HBP_SLOTS) { + ret = -EINVAL; + goto out; + } + + bp = tsk->thread.debug.hbp[idx]; + if (!bp) { + reg = 0; + goto put; + } + + arch_ctrl = counter_arch_bp(bp)->ctrl; + + /* + * Fix up the len because we may have adjusted it + * to compensate for an unaligned address. + */ + while (!(arch_ctrl.len & 0x1)) + arch_ctrl.len >>= 1; + + if (num & 0x1) + reg = bp->attr.bp_addr; + else + reg = encode_ctrl_reg(arch_ctrl); + } + +put: + if (put_user(reg, data)) + ret = -EFAULT; + +out: + return ret; +} + +static int ptrace_sethbpregs(struct task_struct *tsk, long num, + unsigned long __user *data) +{ + int idx, gen_len, gen_type, implied_type, ret = 0; + u32 user_val; + struct perf_event *bp; + struct arch_hw_breakpoint_ctrl ctrl; + struct perf_event_attr attr; + + if (num == 0) + goto out; + else if (num < 0) + implied_type = HW_BREAKPOINT_RW; + else + implied_type = HW_BREAKPOINT_X; + + idx = ptrace_hbp_num_to_idx(num); + if (idx < 0 || idx >= ARM_MAX_HBP_SLOTS) { + ret = -EINVAL; + goto out; + } + + if (get_user(user_val, data)) { + ret = -EFAULT; + goto out; + } + + bp = tsk->thread.debug.hbp[idx]; + if (!bp) { + bp = ptrace_hbp_create(tsk, implied_type); + if (IS_ERR(bp)) { + ret = PTR_ERR(bp); + goto out; + } + tsk->thread.debug.hbp[idx] = bp; + } + + attr = bp->attr; + + if (num & 0x1) { + /* Address */ + attr.bp_addr = user_val; + } else { + /* Control */ + decode_ctrl_reg(user_val, &ctrl); + ret = arch_bp_generic_fields(ctrl, &gen_len, &gen_type); + if (ret) + goto out; + + if ((gen_type & implied_type) != gen_type) { + ret = -EINVAL; + goto out; + } + + attr.bp_len = gen_len; + attr.bp_type = gen_type; + attr.disabled = !ctrl.enabled; + } + + ret = modify_user_hw_breakpoint(bp, &attr); +out: + return ret; +} +#endif + +/* regset get/set implementations */ + +static int gpr_get(struct task_struct *target, + const struct user_regset *regset, + struct membuf to) +{ + return membuf_write(&to, task_pt_regs(target), sizeof(struct pt_regs)); +} + +static int 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 newregs = *task_pt_regs(target); + + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, + &newregs, + 0, sizeof(newregs)); + if (ret) + return ret; + + if (!valid_user_regs(&newregs)) + return -EINVAL; + + *task_pt_regs(target) = newregs; + return 0; +} + +static int fpa_get(struct task_struct *target, + const struct user_regset *regset, + struct membuf to) +{ + return membuf_write(&to, &task_thread_info(target)->fpstate, + sizeof(struct user_fp)); +} + +static int fpa_set(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + const void *kbuf, const void __user *ubuf) +{ + struct thread_info *thread = task_thread_info(target); + + thread->used_cp[1] = thread->used_cp[2] = 1; + + return user_regset_copyin(&pos, &count, &kbuf, &ubuf, + &thread->fpstate, + 0, sizeof(struct user_fp)); +} + +#ifdef CONFIG_VFP +/* + * VFP register get/set implementations. + * + * With respect to the kernel, struct user_fp is divided into three chunks: + * 16 or 32 real VFP registers (d0-d15 or d0-31) + * These are transferred to/from the real registers in the task's + * vfp_hard_struct. The number of registers depends on the kernel + * configuration. + * + * 16 or 0 fake VFP registers (d16-d31 or empty) + * i.e., the user_vfp structure has space for 32 registers even if + * the kernel doesn't have them all. + * + * vfp_get() reads this chunk as zero where applicable + * vfp_set() ignores this chunk + * + * 1 word for the FPSCR + */ +static int vfp_get(struct task_struct *target, + const struct user_regset *regset, + struct membuf to) +{ + struct thread_info *thread = task_thread_info(target); + struct vfp_hard_struct const *vfp = &thread->vfpstate.hard; + const size_t user_fpscr_offset = offsetof(struct user_vfp, fpscr); + + vfp_sync_hwstate(thread); + + membuf_write(&to, vfp->fpregs, sizeof(vfp->fpregs)); + membuf_zero(&to, user_fpscr_offset - sizeof(vfp->fpregs)); + return membuf_store(&to, vfp->fpscr); +} + +/* + * For vfp_set() a read-modify-write is done on the VFP registers, + * in order to avoid writing back a half-modified set of registers on + * failure. + */ +static int vfp_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 thread_info *thread = task_thread_info(target); + struct vfp_hard_struct new_vfp; + const size_t user_fpregs_offset = offsetof(struct user_vfp, fpregs); + const size_t user_fpscr_offset = offsetof(struct user_vfp, fpscr); + + vfp_sync_hwstate(thread); + new_vfp = thread->vfpstate.hard; + + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, + &new_vfp.fpregs, + user_fpregs_offset, + user_fpregs_offset + sizeof(new_vfp.fpregs)); + if (ret) + return ret; + + ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, + user_fpregs_offset + sizeof(new_vfp.fpregs), + user_fpscr_offset); + if (ret) + return ret; + + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, + &new_vfp.fpscr, + user_fpscr_offset, + user_fpscr_offset + sizeof(new_vfp.fpscr)); + if (ret) + return ret; + + thread->vfpstate.hard = new_vfp; + vfp_flush_hwstate(thread); + + return 0; +} +#endif /* CONFIG_VFP */ + +enum arm_regset { + REGSET_GPR, + REGSET_FPR, +#ifdef CONFIG_VFP + REGSET_VFP, +#endif +}; + +static const struct user_regset arm_regsets[] = { + [REGSET_GPR] = { + .core_note_type = NT_PRSTATUS, + .n = ELF_NGREG, + .size = sizeof(u32), + .align = sizeof(u32), + .regset_get = gpr_get, + .set = gpr_set + }, + [REGSET_FPR] = { + /* + * For the FPA regs in fpstate, the real fields are a mixture + * of sizes, so pretend that the registers are word-sized: + */ + .core_note_type = NT_PRFPREG, + .n = sizeof(struct user_fp) / sizeof(u32), + .size = sizeof(u32), + .align = sizeof(u32), + .regset_get = fpa_get, + .set = fpa_set + }, +#ifdef CONFIG_VFP + [REGSET_VFP] = { + /* + * Pretend that the VFP regs are word-sized, since the FPSCR is + * a single word dangling at the end of struct user_vfp: + */ + .core_note_type = NT_ARM_VFP, + .n = ARM_VFPREGS_SIZE / sizeof(u32), + .size = sizeof(u32), + .align = sizeof(u32), + .regset_get = vfp_get, + .set = vfp_set + }, +#endif /* CONFIG_VFP */ +}; + +static const struct user_regset_view user_arm_view = { + .name = "arm", .e_machine = ELF_ARCH, .ei_osabi = ELF_OSABI, + .regsets = arm_regsets, .n = ARRAY_SIZE(arm_regsets) +}; + +const struct user_regset_view *task_user_regset_view(struct task_struct *task) +{ + return &user_arm_view; +} + +long arch_ptrace(struct task_struct *child, long request, + unsigned long addr, unsigned long data) +{ + int ret; + unsigned long __user *datap = (unsigned long __user *) data; + + switch (request) { + case PTRACE_PEEKUSR: + ret = ptrace_read_user(child, addr, datap); + break; + + case PTRACE_POKEUSR: + ret = ptrace_write_user(child, addr, data); + break; + + case PTRACE_GETREGS: + ret = copy_regset_to_user(child, + &user_arm_view, REGSET_GPR, + 0, sizeof(struct pt_regs), + datap); + break; + + case PTRACE_SETREGS: + ret = copy_regset_from_user(child, + &user_arm_view, REGSET_GPR, + 0, sizeof(struct pt_regs), + datap); + break; + + case PTRACE_GETFPREGS: + ret = copy_regset_to_user(child, + &user_arm_view, REGSET_FPR, + 0, sizeof(union fp_state), + datap); + break; + + case PTRACE_SETFPREGS: + ret = copy_regset_from_user(child, + &user_arm_view, REGSET_FPR, + 0, sizeof(union fp_state), + datap); + break; + +#ifdef CONFIG_IWMMXT + case PTRACE_GETWMMXREGS: + ret = ptrace_getwmmxregs(child, datap); + break; + + case PTRACE_SETWMMXREGS: + ret = ptrace_setwmmxregs(child, datap); + break; +#endif + + case PTRACE_GET_THREAD_AREA: + ret = put_user(task_thread_info(child)->tp_value[0], + datap); + break; + + case PTRACE_SET_SYSCALL: + task_thread_info(child)->syscall = data; + ret = 0; + break; + +#ifdef CONFIG_CRUNCH + case PTRACE_GETCRUNCHREGS: + ret = ptrace_getcrunchregs(child, datap); + break; + + case PTRACE_SETCRUNCHREGS: + ret = ptrace_setcrunchregs(child, datap); + break; +#endif + +#ifdef CONFIG_VFP + case PTRACE_GETVFPREGS: + ret = copy_regset_to_user(child, + &user_arm_view, REGSET_VFP, + 0, ARM_VFPREGS_SIZE, + datap); + break; + + case PTRACE_SETVFPREGS: + ret = copy_regset_from_user(child, + &user_arm_view, REGSET_VFP, + 0, ARM_VFPREGS_SIZE, + datap); + break; +#endif + +#ifdef CONFIG_HAVE_HW_BREAKPOINT + case PTRACE_GETHBPREGS: + ret = ptrace_gethbpregs(child, addr, + (unsigned long __user *)data); + break; + case PTRACE_SETHBPREGS: + ret = ptrace_sethbpregs(child, addr, + (unsigned long __user *)data); + break; +#endif + + default: + ret = ptrace_request(child, request, addr, data); + break; + } + + return ret; +} + +enum ptrace_syscall_dir { + PTRACE_SYSCALL_ENTER = 0, + PTRACE_SYSCALL_EXIT, +}; + +static void tracehook_report_syscall(struct pt_regs *regs, + enum ptrace_syscall_dir dir) +{ + unsigned long ip; + + /* + * IP is used to denote syscall entry/exit: + * IP = 0 -> entry, =1 -> exit + */ + ip = regs->ARM_ip; + regs->ARM_ip = dir; + + if (dir == PTRACE_SYSCALL_EXIT) + tracehook_report_syscall_exit(regs, 0); + else if (tracehook_report_syscall_entry(regs)) + current_thread_info()->syscall = -1; + + regs->ARM_ip = ip; +} + +asmlinkage int syscall_trace_enter(struct pt_regs *regs, int scno) +{ + current_thread_info()->syscall = scno; + + if (test_thread_flag(TIF_SYSCALL_TRACE)) + tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER); + + /* Do seccomp after ptrace; syscall may have changed. */ +#ifdef CONFIG_HAVE_ARCH_SECCOMP_FILTER + if (secure_computing() == -1) + return -1; +#else + /* XXX: remove this once OABI gets fixed */ + secure_computing_strict(current_thread_info()->syscall); +#endif + + /* Tracer or seccomp may have changed syscall. */ + scno = current_thread_info()->syscall; + + if (test_thread_flag(TIF_SYSCALL_TRACEPOINT)) + trace_sys_enter(regs, scno); + + audit_syscall_entry(scno, regs->ARM_r0, regs->ARM_r1, regs->ARM_r2, + regs->ARM_r3); + + return scno; +} + +asmlinkage void syscall_trace_exit(struct pt_regs *regs) +{ + /* + * Audit the syscall before anything else, as a debugger may + * come in and change the current registers. + */ + audit_syscall_exit(regs); + + /* + * Note that we haven't updated the ->syscall field for the + * current thread. This isn't a problem because it will have + * been set on syscall entry and there hasn't been an opportunity + * for a PTRACE_SET_SYSCALL since then. + */ + if (test_thread_flag(TIF_SYSCALL_TRACEPOINT)) + trace_sys_exit(regs, regs_return_value(regs)); + + if (test_thread_flag(TIF_SYSCALL_TRACE)) + tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT); +} |