diff options
Diffstat (limited to 'arch/arm64/kernel/ptrace.c')
| -rw-r--r-- | arch/arm64/kernel/ptrace.c | 1126 |
1 files changed, 1126 insertions, 0 deletions
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c new file mode 100644 index 000000000000..490f7537a270 --- /dev/null +++ b/arch/arm64/kernel/ptrace.c @@ -0,0 +1,1126 @@ +/* + * Based on arch/arm/kernel/ptrace.c + * + * By Ross Biro 1/23/92 + * edited by Linus Torvalds + * ARM modifications Copyright (C) 2000 Russell King + * Copyright (C) 2012 ARM Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * 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. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/mm.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/tracehook.h> +#include <linux/elf.h> + +#include <asm/compat.h> +#include <asm/debug-monitors.h> +#include <asm/pgtable.h> +#include <asm/traps.h> +#include <asm/system_misc.h> + +/* + * TODO: does not yet catch signals sent when the child dies. + * in exit.c or in signal.c. + */ + +/* + * Called by kernel/ptrace.c when detaching.. + */ +void ptrace_disable(struct task_struct *child) +{ +} + +/* + * Handle hitting a breakpoint. + */ +static int ptrace_break(struct pt_regs *regs) +{ + siginfo_t info = { + .si_signo = SIGTRAP, + .si_errno = 0, + .si_code = TRAP_BRKPT, + .si_addr = (void __user *)instruction_pointer(regs), + }; + + force_sig_info(SIGTRAP, &info, current); + return 0; +} + +static int arm64_break_trap(unsigned long addr, unsigned int esr, + struct pt_regs *regs) +{ + return ptrace_break(regs); +} + +#ifdef CONFIG_HAVE_HW_BREAKPOINT +/* + * 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); + siginfo_t info = { + .si_signo = SIGTRAP, + .si_errno = 0, + .si_code = TRAP_HWBKPT, + .si_addr = (void __user *)(bkpt->trigger), + }; + +#ifdef CONFIG_COMPAT + int i; + + if (!is_compat_task()) + goto send_sig; + + for (i = 0; i < ARM_MAX_BRP; ++i) { + if (current->thread.debug.hbp_break[i] == bp) { + info.si_errno = (i << 1) + 1; + break; + } + } + for (i = ARM_MAX_BRP; i < ARM_MAX_HBP_SLOTS && !bp; ++i) { + if (current->thread.debug.hbp_watch[i] == bp) { + info.si_errno = -((i << 1) + 1); + break; + } + } + +send_sig: +#endif + force_sig_info(SIGTRAP, &info, current); +} + +/* + * 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_BRP; i++) { + if (t->debug.hbp_break[i]) { + unregister_hw_breakpoint(t->debug.hbp_break[i]); + t->debug.hbp_break[i] = NULL; + } + } + + for (i = 0; i < ARM_MAX_WRP; i++) { + if (t->debug.hbp_watch[i]) { + unregister_hw_breakpoint(t->debug.hbp_watch[i]); + t->debug.hbp_watch[i] = NULL; + } + } +} + +void ptrace_hw_copy_thread(struct task_struct *tsk) +{ + memset(&tsk->thread.debug, 0, sizeof(struct debug_info)); +} + +static struct perf_event *ptrace_hbp_get_event(unsigned int note_type, + struct task_struct *tsk, + unsigned long idx) +{ + struct perf_event *bp = ERR_PTR(-EINVAL); + + switch (note_type) { + case NT_ARM_HW_BREAK: + if (idx < ARM_MAX_BRP) + bp = tsk->thread.debug.hbp_break[idx]; + break; + case NT_ARM_HW_WATCH: + if (idx < ARM_MAX_WRP) + bp = tsk->thread.debug.hbp_watch[idx]; + break; + } + + return bp; +} + +static int ptrace_hbp_set_event(unsigned int note_type, + struct task_struct *tsk, + unsigned long idx, + struct perf_event *bp) +{ + int err = -EINVAL; + + switch (note_type) { + case NT_ARM_HW_BREAK: + if (idx < ARM_MAX_BRP) { + tsk->thread.debug.hbp_break[idx] = bp; + err = 0; + } + break; + case NT_ARM_HW_WATCH: + if (idx < ARM_MAX_WRP) { + tsk->thread.debug.hbp_watch[idx] = bp; + err = 0; + } + break; + } + + return err; +} + +static struct perf_event *ptrace_hbp_create(unsigned int note_type, + struct task_struct *tsk, + unsigned long idx) +{ + struct perf_event *bp; + struct perf_event_attr attr; + int err, type; + + switch (note_type) { + case NT_ARM_HW_BREAK: + type = HW_BREAKPOINT_X; + break; + case NT_ARM_HW_WATCH: + type = HW_BREAKPOINT_RW; + break; + default: + return ERR_PTR(-EINVAL); + } + + ptrace_breakpoint_init(&attr); + + /* + * Initialise fields to sane defaults + * (i.e. values that will pass validation). + */ + attr.bp_addr = 0; + attr.bp_len = HW_BREAKPOINT_LEN_4; + attr.bp_type = type; + attr.disabled = 1; + + bp = register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL, tsk); + if (IS_ERR(bp)) + return bp; + + err = ptrace_hbp_set_event(note_type, tsk, idx, bp); + if (err) + return ERR_PTR(err); + + return bp; +} + +static int ptrace_hbp_fill_attr_ctrl(unsigned int note_type, + struct arch_hw_breakpoint_ctrl ctrl, + struct perf_event_attr *attr) +{ + int err, len, type; + + err = arch_bp_generic_fields(ctrl, &len, &type); + if (err) + return err; + + switch (note_type) { + case NT_ARM_HW_BREAK: + if ((type & HW_BREAKPOINT_X) != type) + return -EINVAL; + break; + case NT_ARM_HW_WATCH: + if ((type & HW_BREAKPOINT_RW) != type) + return -EINVAL; + break; + default: + return -EINVAL; + } + + attr->bp_len = len; + attr->bp_type = type; + attr->disabled = !ctrl.enabled; + + return 0; +} + +static int ptrace_hbp_get_resource_info(unsigned int note_type, u32 *info) +{ + u8 num; + u32 reg = 0; + + switch (note_type) { + case NT_ARM_HW_BREAK: + num = hw_breakpoint_slots(TYPE_INST); + break; + case NT_ARM_HW_WATCH: + num = hw_breakpoint_slots(TYPE_DATA); + break; + default: + return -EINVAL; + } + + reg |= debug_monitors_arch(); + reg <<= 8; + reg |= num; + + *info = reg; + return 0; +} + +static int ptrace_hbp_get_ctrl(unsigned int note_type, + struct task_struct *tsk, + unsigned long idx, + u32 *ctrl) +{ + struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx); + + if (IS_ERR(bp)) + return PTR_ERR(bp); + + *ctrl = bp ? encode_ctrl_reg(counter_arch_bp(bp)->ctrl) : 0; + return 0; +} + +static int ptrace_hbp_get_addr(unsigned int note_type, + struct task_struct *tsk, + unsigned long idx, + u64 *addr) +{ + struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx); + + if (IS_ERR(bp)) + return PTR_ERR(bp); + + *addr = bp ? bp->attr.bp_addr : 0; + return 0; +} + +static struct perf_event *ptrace_hbp_get_initialised_bp(unsigned int note_type, + struct task_struct *tsk, + unsigned long idx) +{ + struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx); + + if (!bp) + bp = ptrace_hbp_create(note_type, tsk, idx); + + return bp; +} + +static int ptrace_hbp_set_ctrl(unsigned int note_type, + struct task_struct *tsk, + unsigned long idx, + u32 uctrl) +{ + int err; + struct perf_event *bp; + struct perf_event_attr attr; + struct arch_hw_breakpoint_ctrl ctrl; + + bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx); + if (IS_ERR(bp)) { + err = PTR_ERR(bp); + return err; + } + + attr = bp->attr; + decode_ctrl_reg(uctrl, &ctrl); + err = ptrace_hbp_fill_attr_ctrl(note_type, ctrl, &attr); + if (err) + return err; + + return modify_user_hw_breakpoint(bp, &attr); +} + +static int ptrace_hbp_set_addr(unsigned int note_type, + struct task_struct *tsk, + unsigned long idx, + u64 addr) +{ + int err; + struct perf_event *bp; + struct perf_event_attr attr; + + bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx); + if (IS_ERR(bp)) { + err = PTR_ERR(bp); + return err; + } + + attr = bp->attr; + attr.bp_addr = addr; + err = modify_user_hw_breakpoint(bp, &attr); + return err; +} + +#define PTRACE_HBP_ADDR_SZ sizeof(u64) +#define PTRACE_HBP_CTRL_SZ sizeof(u32) +#define PTRACE_HBP_REG_OFF sizeof(u32) + +static int hw_break_get(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + void *kbuf, void __user *ubuf) +{ + unsigned int note_type = regset->core_note_type; + int ret, idx = 0, offset = PTRACE_HBP_REG_OFF, limit; + u32 info, ctrl; + u64 addr; + + /* Resource info */ + ret = ptrace_hbp_get_resource_info(note_type, &info); + if (ret) + return ret; + + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &info, 0, 4); + if (ret) + return ret; + + /* (address, ctrl) registers */ + limit = regset->n * regset->size; + while (count && offset < limit) { + ret = ptrace_hbp_get_addr(note_type, target, idx, &addr); + if (ret) + return ret; + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &addr, + offset, offset + PTRACE_HBP_ADDR_SZ); + if (ret) + return ret; + offset += PTRACE_HBP_ADDR_SZ; + + ret = ptrace_hbp_get_ctrl(note_type, target, idx, &ctrl); + if (ret) + return ret; + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &ctrl, + offset, offset + PTRACE_HBP_CTRL_SZ); + if (ret) + return ret; + offset += PTRACE_HBP_CTRL_SZ; + idx++; + } + + return 0; +} + +static int hw_break_set(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + const void *kbuf, const void __user *ubuf) +{ + unsigned int note_type = regset->core_note_type; + int ret, idx = 0, offset = PTRACE_HBP_REG_OFF, limit; + u32 ctrl; + u64 addr; + + /* Resource info */ + ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 0, 4); + if (ret) + return ret; + + /* (address, ctrl) registers */ + limit = regset->n * regset->size; + while (count && offset < limit) { + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &addr, + offset, offset + PTRACE_HBP_ADDR_SZ); + if (ret) + return ret; + ret = ptrace_hbp_set_addr(note_type, target, idx, addr); + if (ret) + return ret; + offset += PTRACE_HBP_ADDR_SZ; + + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ctrl, + offset, offset + PTRACE_HBP_CTRL_SZ); + if (ret) + return ret; + ret = ptrace_hbp_set_ctrl(note_type, target, idx, ctrl); + if (ret) + return ret; + offset += PTRACE_HBP_CTRL_SZ; + idx++; + } + + return 0; +} +#endif /* CONFIG_HAVE_HW_BREAKPOINT */ + +static int gpr_get(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + void *kbuf, void __user *ubuf) +{ + struct user_pt_regs *uregs = &task_pt_regs(target)->user_regs; + return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1); +} + +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 user_pt_regs newregs; + + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newregs, 0, -1); + if (ret) + return ret; + + if (!valid_user_regs(&newregs)) + return -EINVAL; + + task_pt_regs(target)->user_regs = newregs; + return 0; +} + +/* + * TODO: update fp accessors for lazy context switching (sync/flush hwstate) + */ +static int fpr_get(struct task_struct *target, const struct user_regset *regset, + unsigned int pos, unsigned int count, + void *kbuf, void __user *ubuf) +{ + struct user_fpsimd_state *uregs; + uregs = &target->thread.fpsimd_state.user_fpsimd; + return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1); +} + +static int fpr_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 user_fpsimd_state newstate; + + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newstate, 0, -1); + if (ret) + return ret; + + target->thread.fpsimd_state.user_fpsimd = newstate; + return ret; +} + +static int tls_get(struct task_struct *target, const struct user_regset *regset, + unsigned int pos, unsigned int count, + void *kbuf, void __user *ubuf) +{ + unsigned long *tls = &target->thread.tp_value; + return user_regset_copyout(&pos, &count, &kbuf, &ubuf, tls, 0, -1); +} + +static int tls_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; + unsigned long tls; + + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1); + if (ret) + return ret; + + target->thread.tp_value = tls; + return ret; +} + +enum aarch64_regset { + REGSET_GPR, + REGSET_FPR, + REGSET_TLS, +#ifdef CONFIG_HAVE_HW_BREAKPOINT + REGSET_HW_BREAK, + REGSET_HW_WATCH, +#endif +}; + +static const struct user_regset aarch64_regsets[] = { + [REGSET_GPR] = { + .core_note_type = NT_PRSTATUS, + .n = sizeof(struct user_pt_regs) / sizeof(u64), + .size = sizeof(u64), + .align = sizeof(u64), + .get = gpr_get, + .set = gpr_set + }, + [REGSET_FPR] = { + .core_note_type = NT_PRFPREG, + .n = sizeof(struct user_fpsimd_state) / sizeof(u32), + /* + * We pretend we have 32-bit registers because the fpsr and + * fpcr are 32-bits wide. + */ + .size = sizeof(u32), + .align = sizeof(u32), + .get = fpr_get, + .set = fpr_set + }, + [REGSET_TLS] = { + .core_note_type = NT_ARM_TLS, + .n = 1, + .size = sizeof(void *), + .align = sizeof(void *), + .get = tls_get, + .set = tls_set, + }, +#ifdef CONFIG_HAVE_HW_BREAKPOINT + [REGSET_HW_BREAK] = { + .core_note_type = NT_ARM_HW_BREAK, + .n = sizeof(struct user_hwdebug_state) / sizeof(u32), + .size = sizeof(u32), + .align = sizeof(u32), + .get = hw_break_get, + .set = hw_break_set, + }, + [REGSET_HW_WATCH] = { + .core_note_type = NT_ARM_HW_WATCH, + .n = sizeof(struct user_hwdebug_state) / sizeof(u32), + .size = sizeof(u32), + .align = sizeof(u32), + .get = hw_break_get, + .set = hw_break_set, + }, +#endif +}; + +static const struct user_regset_view user_aarch64_view = { + .name = "aarch64", .e_machine = EM_AARCH64, + .regsets = aarch64_regsets, .n = ARRAY_SIZE(aarch64_regsets) +}; + +#ifdef CONFIG_COMPAT +#include <linux/compat.h> + +enum compat_regset { + REGSET_COMPAT_GPR, + REGSET_COMPAT_VFP, +}; + +static int compat_gpr_get(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + void *kbuf, void __user *ubuf) +{ + int ret = 0; + unsigned int i, start, num_regs; + + /* Calculate the number of AArch32 registers contained in count */ + num_regs = count / regset->size; + + /* Convert pos into an register number */ + start = pos / regset->size; + + if (start + num_regs > regset->n) + return -EIO; + + for (i = 0; i < num_regs; ++i) { + unsigned int idx = start + i; + void *reg; + + switch (idx) { + case 15: + reg = (void *)&task_pt_regs(target)->pc; + break; + case 16: + reg = (void *)&task_pt_regs(target)->pstate; + break; + case 17: + reg = (void *)&task_pt_regs(target)->orig_x0; + break; + default: + reg = (void *)&task_pt_regs(target)->regs[idx]; + } + + ret = copy_to_user(ubuf, reg, sizeof(compat_ulong_t)); + + if (ret) + break; + else + ubuf += sizeof(compat_ulong_t); + } + + return ret; +} + +static int compat_gpr_set(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + const void *kbuf, const void __user *ubuf) +{ + struct pt_regs newregs; + int ret = 0; + unsigned int i, start, num_regs; + + /* Calculate the number of AArch32 registers contained in count */ + num_regs = count / regset->size; + + /* Convert pos into an register number */ + start = pos / regset->size; + + if (start + num_regs > regset->n) + return -EIO; + + newregs = *task_pt_regs(target); + + for (i = 0; i < num_regs; ++i) { + unsigned int idx = start + i; + void *reg; + + switch (idx) { + case 15: + reg = (void *)&newregs.pc; + break; + case 16: + reg = (void *)&newregs.pstate; + break; + case 17: + reg = (void *)&newregs.orig_x0; + break; + default: + reg = (void *)&newregs.regs[idx]; + } + + ret = copy_from_user(reg, ubuf, sizeof(compat_ulong_t)); + + if (ret) + goto out; + else + ubuf += sizeof(compat_ulong_t); + } + + if (valid_user_regs(&newregs.user_regs)) + *task_pt_regs(target) = newregs; + else + ret = -EINVAL; + +out: + return ret; +} + +static int compat_vfp_get(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + void *kbuf, void __user *ubuf) +{ + struct user_fpsimd_state *uregs; + compat_ulong_t fpscr; + int ret; + + uregs = &target->thread.fpsimd_state.user_fpsimd; + + /* + * The VFP registers are packed into the fpsimd_state, so they all sit + * nicely together for us. We just need to create the fpscr separately. + */ + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, + VFP_STATE_SIZE - sizeof(compat_ulong_t)); + + if (count && !ret) { + fpscr = (uregs->fpsr & VFP_FPSCR_STAT_MASK) | + (uregs->fpcr & VFP_FPSCR_CTRL_MASK); + ret = put_user(fpscr, (compat_ulong_t *)ubuf); + } + + return ret; +} + +static int compat_vfp_set(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + const void *kbuf, const void __user *ubuf) +{ + struct user_fpsimd_state *uregs; + compat_ulong_t fpscr; + int ret; + + if (pos + count > VFP_STATE_SIZE) + return -EIO; + + uregs = &target->thread.fpsimd_state.user_fpsimd; + + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0, + VFP_STATE_SIZE - sizeof(compat_ulong_t)); + + if (count && !ret) { + ret = get_user(fpscr, (compat_ulong_t *)ubuf); + uregs->fpsr = fpscr & VFP_FPSCR_STAT_MASK; + uregs->fpcr = fpscr & VFP_FPSCR_CTRL_MASK; + } + + return ret; +} + +static const struct user_regset aarch32_regsets[] = { + [REGSET_COMPAT_GPR] = { + .core_note_type = NT_PRSTATUS, + .n = COMPAT_ELF_NGREG, + .size = sizeof(compat_elf_greg_t), + .align = sizeof(compat_elf_greg_t), + .get = compat_gpr_get, + .set = compat_gpr_set + }, + [REGSET_COMPAT_VFP] = { + .core_note_type = NT_ARM_VFP, + .n = VFP_STATE_SIZE / sizeof(compat_ulong_t), + .size = sizeof(compat_ulong_t), + .align = sizeof(compat_ulong_t), + .get = compat_vfp_get, + .set = compat_vfp_set + }, +}; + +static const struct user_regset_view user_aarch32_view = { + .name = "aarch32", .e_machine = EM_ARM, + .regsets = aarch32_regsets, .n = ARRAY_SIZE(aarch32_regsets) +}; + +int aarch32_break_trap(struct pt_regs *regs) +{ + unsigned int instr; + bool bp = false; + void __user *pc = (void __user *)instruction_pointer(regs); + + if (compat_thumb_mode(regs)) { + /* get 16-bit Thumb instruction */ + get_user(instr, (u16 __user *)pc); + if (instr == AARCH32_BREAK_THUMB2_LO) { + /* get second half of 32-bit Thumb-2 instruction */ + get_user(instr, (u16 __user *)(pc + 2)); + bp = instr == AARCH32_BREAK_THUMB2_HI; + } else { + bp = instr == AARCH32_BREAK_THUMB; + } + } else { + /* 32-bit ARM instruction */ + get_user(instr, (u32 __user *)pc); + bp = (instr & ~0xf0000000) == AARCH32_BREAK_ARM; + } + + if (bp) + return ptrace_break(regs); + return 1; +} + +static int compat_ptrace_read_user(struct task_struct *tsk, compat_ulong_t off, + compat_ulong_t __user *ret) +{ + compat_ulong_t tmp; + + if (off & 3) + return -EIO; + + 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(compat_elf_gregset_t)) + return copy_regset_to_user(tsk, &user_aarch32_view, + REGSET_COMPAT_GPR, off, + sizeof(compat_ulong_t), ret); + else if (off >= COMPAT_USER_SZ) + return -EIO; + else + tmp = 0; + + return put_user(tmp, ret); +} + +static int compat_ptrace_write_user(struct task_struct *tsk, compat_ulong_t off, + compat_ulong_t val) +{ + int ret; + + if (off & 3 || off >= COMPAT_USER_SZ) + return -EIO; + + if (off >= sizeof(compat_elf_gregset_t)) + return 0; + + ret = copy_regset_from_user(tsk, &user_aarch32_view, + REGSET_COMPAT_GPR, off, + sizeof(compat_ulong_t), + &val); + return ret; +} + +#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 compat_ptrace_hbp_num_to_idx(compat_long_t num) +{ + return (abs(num) - 1) >> 1; +} + +static int compat_ptrace_hbp_get_resource_info(u32 *kdata) +{ + 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 = debug_monitors_arch(); + wp_len = 8; + reg |= debug_arch; + reg <<= 8; + reg |= wp_len; + reg <<= 8; + reg |= num_wrps; + reg <<= 8; + reg |= num_brps; + + *kdata = reg; + return 0; +} + +static int compat_ptrace_hbp_get(unsigned int note_type, + struct task_struct *tsk, + compat_long_t num, + u32 *kdata) +{ + u64 addr = 0; + u32 ctrl = 0; + + int err, idx = compat_ptrace_hbp_num_to_idx(num);; + + if (num & 1) { + err = ptrace_hbp_get_addr(note_type, tsk, idx, &addr); + *kdata = (u32)addr; + } else { + err = ptrace_hbp_get_ctrl(note_type, tsk, idx, &ctrl); + *kdata = ctrl; + } + + return err; +} + +static int compat_ptrace_hbp_set(unsigned int note_type, + struct task_struct *tsk, + compat_long_t num, + u32 *kdata) +{ + u64 addr; + u32 ctrl; + + int err, idx = compat_ptrace_hbp_num_to_idx(num); + + if (num & 1) { + addr = *kdata; + err = ptrace_hbp_set_addr(note_type, tsk, idx, addr); + } else { + ctrl = *kdata; + err = ptrace_hbp_set_ctrl(note_type, tsk, idx, ctrl); + } + + return err; +} + +static int compat_ptrace_gethbpregs(struct task_struct *tsk, compat_long_t num, + compat_ulong_t __user *data) +{ + int ret; + u32 kdata; + mm_segment_t old_fs = get_fs(); + + set_fs(KERNEL_DS); + /* Watchpoint */ + if (num < 0) { + ret = compat_ptrace_hbp_get(NT_ARM_HW_WATCH, tsk, num, &kdata); + /* Resource info */ + } else if (num == 0) { + ret = compat_ptrace_hbp_get_resource_info(&kdata); + /* Breakpoint */ + } else { + ret = compat_ptrace_hbp_get(NT_ARM_HW_BREAK, tsk, num, &kdata); + } + set_fs(old_fs); + + if (!ret) + ret = put_user(kdata, data); + + return ret; +} + +static int compat_ptrace_sethbpregs(struct task_struct *tsk, compat_long_t num, + compat_ulong_t __user *data) +{ + int ret; + u32 kdata = 0; + mm_segment_t old_fs = get_fs(); + + if (num == 0) + return 0; + + ret = get_user(kdata, data); + if (ret) + return ret; + + set_fs(KERNEL_DS); + if (num < 0) + ret = compat_ptrace_hbp_set(NT_ARM_HW_WATCH, tsk, num, &kdata); + else + ret = compat_ptrace_hbp_set(NT_ARM_HW_BREAK, tsk, num, &kdata); + set_fs(old_fs); + + return ret; +} +#endif /* CONFIG_HAVE_HW_BREAKPOINT */ + +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; + + switch (request) { + case PTRACE_PEEKUSR: + ret = compat_ptrace_read_user(child, addr, datap); + break; + + case PTRACE_POKEUSR: + ret = compat_ptrace_write_user(child, addr, data); + break; + + case PTRACE_GETREGS: + ret = copy_regset_to_user(child, + &user_aarch32_view, + REGSET_COMPAT_GPR, + 0, sizeof(compat_elf_gregset_t), + datap); + break; + + case PTRACE_SETREGS: + ret = copy_regset_from_user(child, + &user_aarch32_view, + REGSET_COMPAT_GPR, + 0, sizeof(compat_elf_gregset_t), + datap); + break; + + case PTRACE_GET_THREAD_AREA: + ret = put_user((compat_ulong_t)child->thread.tp_value, + (compat_ulong_t __user *)datap); + break; + + case PTRACE_SET_SYSCALL: + task_pt_regs(child)->syscallno = data; + ret = 0; + break; + + case COMPAT_PTRACE_GETVFPREGS: + ret = copy_regset_to_user(child, + &user_aarch32_view, + REGSET_COMPAT_VFP, + 0, VFP_STATE_SIZE, + datap); + break; + + case COMPAT_PTRACE_SETVFPREGS: + ret = copy_regset_from_user(child, + &user_aarch32_view, + REGSET_COMPAT_VFP, + 0, VFP_STATE_SIZE, + datap); + break; + +#ifdef CONFIG_HAVE_HW_BREAKPOINT + case PTRACE_GETHBPREGS: + ret = compat_ptrace_gethbpregs(child, addr, datap); + break; + + case PTRACE_SETHBPREGS: + ret = compat_ptrace_sethbpregs(child, addr, datap); + break; +#endif + + default: + ret = compat_ptrace_request(child, request, addr, + data); + break; + } + + return ret; +} +#endif /* CONFIG_COMPAT */ + +const struct user_regset_view *task_user_regset_view(struct task_struct *task) +{ +#ifdef CONFIG_COMPAT + if (is_compat_thread(task_thread_info(task))) + return &user_aarch32_view; +#endif + return &user_aarch64_view; +} + +long arch_ptrace(struct task_struct *child, long request, + unsigned long addr, unsigned long data) +{ + return ptrace_request(child, request, addr, data); +} + + +static int __init ptrace_break_init(void) +{ + hook_debug_fault_code(DBG_ESR_EVT_BRK, arm64_break_trap, SIGTRAP, + TRAP_BRKPT, "ptrace BRK handler"); + return 0; +} +core_initcall(ptrace_break_init); + + +asmlinkage int syscall_trace(int dir, struct pt_regs *regs) +{ + unsigned long saved_reg; + + if (!test_thread_flag(TIF_SYSCALL_TRACE)) + return regs->syscallno; + + if (is_compat_task()) { + /* AArch32 uses ip (r12) for scratch */ + saved_reg = regs->regs[12]; + regs->regs[12] = dir; + } else { + /* + * Save X7. X7 is used to denote syscall entry/exit: + * X7 = 0 -> entry, = 1 -> exit + */ + saved_reg = regs->regs[7]; + regs->regs[7] = dir; + } + + if (dir) + tracehook_report_syscall_exit(regs, 0); + else if (tracehook_report_syscall_entry(regs)) + regs->syscallno = ~0UL; + + if (is_compat_task()) + regs->regs[12] = saved_reg; + else + regs->regs[7] = saved_reg; + + return regs->syscallno; +} |