diff options
Diffstat (limited to 'arch/arm64/kernel/ptrace.c')
| -rw-r--r-- | arch/arm64/kernel/ptrace.c | 1781 |
1 files changed, 1781 insertions, 0 deletions
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c new file mode 100644 index 000000000..9579968e7 --- /dev/null +++ b/arch/arm64/kernel/ptrace.c @@ -0,0 +1,1781 @@ +/* + * 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/audit.h> +#include <linux/compat.h> +#include <linux/kernel.h> +#include <linux/sched/signal.h> +#include <linux/sched/task_stack.h> +#include <linux/mm.h> +#include <linux/nospec.h> +#include <linux/smp.h> +#include <linux/ptrace.h> +#include <linux/user.h> +#include <linux/seccomp.h> +#include <linux/security.h> +#include <linux/init.h> +#include <linux/signal.h> +#include <linux/string.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/cpufeature.h> +#include <asm/debug-monitors.h> +#include <asm/fpsimd.h> +#include <asm/pgtable.h> +#include <asm/stacktrace.h> +#include <asm/syscall.h> +#include <asm/traps.h> +#include <asm/system_misc.h> + +#define CREATE_TRACE_POINTS +#include <trace/events/syscalls.h> + +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} +#define GPR_OFFSET_NAME(r) \ + {.name = "x" #r, .offset = offsetof(struct pt_regs, regs[r])} + +static const struct pt_regs_offset regoffset_table[] = { + GPR_OFFSET_NAME(0), + GPR_OFFSET_NAME(1), + GPR_OFFSET_NAME(2), + GPR_OFFSET_NAME(3), + GPR_OFFSET_NAME(4), + GPR_OFFSET_NAME(5), + GPR_OFFSET_NAME(6), + GPR_OFFSET_NAME(7), + GPR_OFFSET_NAME(8), + GPR_OFFSET_NAME(9), + GPR_OFFSET_NAME(10), + GPR_OFFSET_NAME(11), + GPR_OFFSET_NAME(12), + GPR_OFFSET_NAME(13), + GPR_OFFSET_NAME(14), + GPR_OFFSET_NAME(15), + GPR_OFFSET_NAME(16), + GPR_OFFSET_NAME(17), + GPR_OFFSET_NAME(18), + GPR_OFFSET_NAME(19), + GPR_OFFSET_NAME(20), + GPR_OFFSET_NAME(21), + GPR_OFFSET_NAME(22), + GPR_OFFSET_NAME(23), + GPR_OFFSET_NAME(24), + GPR_OFFSET_NAME(25), + GPR_OFFSET_NAME(26), + GPR_OFFSET_NAME(27), + GPR_OFFSET_NAME(28), + GPR_OFFSET_NAME(29), + GPR_OFFSET_NAME(30), + {.name = "lr", .offset = offsetof(struct pt_regs, regs[30])}, + REG_OFFSET_NAME(sp), + REG_OFFSET_NAME(pc), + REG_OFFSET_NAME(pstate), + 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_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. + */ +static bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr) +{ + return ((addr & ~(THREAD_SIZE - 1)) == + (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))) || + on_irq_stack(addr, NULL); +} + +/** + * 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; +} + +/* + * 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) +{ + /* + * This would be better off in core code, but PTRACE_DETACH has + * grown its fair share of arch-specific worts and changing it + * is likely to cause regressions on obscure architectures. + */ + user_disable_single_step(child); +} + +#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; + + clear_siginfo(&info); + info.si_signo = SIGTRAP; + info.si_errno = 0; + info.si_code = TRAP_HWBKPT; + info.si_addr = (void __user *)(bkpt->trigger); + +#ifdef CONFIG_COMPAT + if (is_compat_task()) { + int si_errno = 0; + int i; + + for (i = 0; i < ARM_MAX_BRP; ++i) { + if (current->thread.debug.hbp_break[i] == bp) { + si_errno = (i << 1) + 1; + break; + } + } + + for (i = 0; i < ARM_MAX_WRP; ++i) { + if (current->thread.debug.hbp_watch[i] == bp) { + si_errno = -((i << 1) + 1); + break; + } + } + force_sig_ptrace_errno_trap(si_errno, (void __user *)bkpt->trigger); + } +#endif + arm64_force_sig_info(&info, "Hardware breakpoint trap (ptrace)", 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) + goto out; + idx = array_index_nospec(idx, ARM_MAX_BRP); + bp = tsk->thread.debug.hbp_break[idx]; + break; + case NT_ARM_HW_WATCH: + if (idx >= ARM_MAX_WRP) + goto out; + idx = array_index_nospec(idx, ARM_MAX_WRP); + bp = tsk->thread.debug.hbp_watch[idx]; + break; + } + +out: + 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) + goto out; + idx = array_index_nospec(idx, ARM_MAX_BRP); + tsk->thread.debug.hbp_break[idx] = bp; + err = 0; + break; + case NT_ARM_HW_WATCH: + if (idx >= ARM_MAX_WRP) + goto out; + idx = array_index_nospec(idx, ARM_MAX_WRP); + tsk->thread.debug.hbp_watch[idx] = bp; + err = 0; + break; + } + +out: + 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, offset, disabled = !ctrl.enabled; + + attr->disabled = disabled; + if (disabled) + return 0; + + err = arch_bp_generic_fields(ctrl, &len, &type, &offset); + 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->bp_addr += offset; + + 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 ? counter_arch_bp(bp)->address : 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_PAD_SZ 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, 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, + sizeof(info)); + if (ret) + return ret; + + /* Pad */ + offset = offsetof(struct user_hwdebug_state, pad); + ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, offset, + offset + PTRACE_HBP_PAD_SZ); + if (ret) + return ret; + + /* (address, ctrl) registers */ + offset = offsetof(struct user_hwdebug_state, dbg_regs); + 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; + + ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, + offset, + offset + PTRACE_HBP_PAD_SZ); + if (ret) + return ret; + offset += PTRACE_HBP_PAD_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, limit; + u32 ctrl; + u64 addr; + + /* Resource info and pad */ + offset = offsetof(struct user_hwdebug_state, dbg_regs); + ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 0, offset); + if (ret) + return ret; + + /* (address, ctrl) registers */ + limit = regset->n * regset->size; + while (count && offset < limit) { + if (count < PTRACE_HBP_ADDR_SZ) + return -EINVAL; + 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; + + if (!count) + break; + 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; + + ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, + offset, + offset + PTRACE_HBP_PAD_SZ); + if (ret) + return ret; + offset += PTRACE_HBP_PAD_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 = task_pt_regs(target)->user_regs; + + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newregs, 0, -1); + if (ret) + return ret; + + if (!valid_user_regs(&newregs, target)) + return -EINVAL; + + task_pt_regs(target)->user_regs = newregs; + return 0; +} + +static int fpr_active(struct task_struct *target, const struct user_regset *regset) +{ + if (!system_supports_fpsimd()) + return -ENODEV; + return regset->n; +} + +/* + * 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, unsigned int start_pos) +{ + struct user_fpsimd_state *uregs; + + sve_sync_to_fpsimd(target); + + uregs = &target->thread.uw.fpsimd_state; + + return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, + start_pos, start_pos + sizeof(*uregs)); +} + +static int fpr_get(struct task_struct *target, const struct user_regset *regset, + unsigned int pos, unsigned int count, + void *kbuf, void __user *ubuf) +{ + if (!system_supports_fpsimd()) + return -EINVAL; + + if (target == current) + fpsimd_preserve_current_state(); + + return __fpr_get(target, regset, pos, count, kbuf, ubuf, 0); +} + +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, + unsigned int start_pos) +{ + int ret; + struct user_fpsimd_state newstate; + + /* + * Ensure target->thread.uw.fpsimd_state is up to date, so that a + * short copyin can't resurrect stale data. + */ + sve_sync_to_fpsimd(target); + + newstate = target->thread.uw.fpsimd_state; + + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newstate, + start_pos, start_pos + sizeof(newstate)); + if (ret) + return ret; + + target->thread.uw.fpsimd_state = newstate; + + return ret; +} + +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; + + if (!system_supports_fpsimd()) + return -EINVAL; + + ret = __fpr_set(target, regset, pos, count, kbuf, ubuf, 0); + if (ret) + return ret; + + sve_sync_from_fpsimd_zeropad(target); + fpsimd_flush_task_state(target); + + 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.uw.tp_value; + + if (target == current) + tls_preserve_current_state(); + + 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 = target->thread.uw.tp_value; + + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1); + if (ret) + return ret; + + target->thread.uw.tp_value = tls; + return ret; +} + +static int system_call_get(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + void *kbuf, void __user *ubuf) +{ + int syscallno = task_pt_regs(target)->syscallno; + + return user_regset_copyout(&pos, &count, &kbuf, &ubuf, + &syscallno, 0, -1); +} + +static int system_call_set(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + const void *kbuf, const void __user *ubuf) +{ + int syscallno = task_pt_regs(target)->syscallno; + int ret; + + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &syscallno, 0, -1); + if (ret) + return ret; + + task_pt_regs(target)->syscallno = syscallno; + return ret; +} + +#ifdef CONFIG_ARM64_SVE + +static void sve_init_header_from_task(struct user_sve_header *header, + struct task_struct *target) +{ + unsigned int vq; + + memset(header, 0, sizeof(*header)); + + header->flags = test_tsk_thread_flag(target, TIF_SVE) ? + SVE_PT_REGS_SVE : SVE_PT_REGS_FPSIMD; + if (test_tsk_thread_flag(target, TIF_SVE_VL_INHERIT)) + header->flags |= SVE_PT_VL_INHERIT; + + header->vl = target->thread.sve_vl; + vq = sve_vq_from_vl(header->vl); + + header->max_vl = sve_max_vl; + header->size = SVE_PT_SIZE(vq, header->flags); + header->max_size = SVE_PT_SIZE(sve_vq_from_vl(header->max_vl), + SVE_PT_REGS_SVE); +} + +static unsigned int sve_size_from_header(struct user_sve_header const *header) +{ + return ALIGN(header->size, SVE_VQ_BYTES); +} + +static unsigned int sve_get_size(struct task_struct *target, + const struct user_regset *regset) +{ + struct user_sve_header header; + + if (!system_supports_sve()) + return 0; + + sve_init_header_from_task(&header, target); + return sve_size_from_header(&header); +} + +static int sve_get(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + void *kbuf, void __user *ubuf) +{ + int ret; + struct user_sve_header header; + unsigned int vq; + unsigned long start, end; + + if (!system_supports_sve()) + return -EINVAL; + + /* Header */ + sve_init_header_from_task(&header, target); + vq = sve_vq_from_vl(header.vl); + + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &header, + 0, sizeof(header)); + if (ret) + return ret; + + if (target == current) + fpsimd_preserve_current_state(); + + /* Registers: FPSIMD-only case */ + + BUILD_BUG_ON(SVE_PT_FPSIMD_OFFSET != sizeof(header)); + if ((header.flags & SVE_PT_REGS_MASK) == SVE_PT_REGS_FPSIMD) + return __fpr_get(target, regset, pos, count, kbuf, ubuf, + SVE_PT_FPSIMD_OFFSET); + + /* Otherwise: full SVE case */ + + BUILD_BUG_ON(SVE_PT_SVE_OFFSET != sizeof(header)); + start = SVE_PT_SVE_OFFSET; + end = SVE_PT_SVE_FFR_OFFSET(vq) + SVE_PT_SVE_FFR_SIZE(vq); + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, + target->thread.sve_state, + start, end); + if (ret) + return ret; + + start = end; + end = SVE_PT_SVE_FPSR_OFFSET(vq); + ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, + start, end); + if (ret) + return ret; + + /* + * Copy fpsr, and fpcr which must follow contiguously in + * struct fpsimd_state: + */ + start = end; + end = SVE_PT_SVE_FPCR_OFFSET(vq) + SVE_PT_SVE_FPCR_SIZE; + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, + &target->thread.uw.fpsimd_state.fpsr, + start, end); + if (ret) + return ret; + + start = end; + end = sve_size_from_header(&header); + return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, + start, end); +} + +static int sve_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_sve_header header; + unsigned int vq; + unsigned long start, end; + + if (!system_supports_sve()) + return -EINVAL; + + /* Header */ + if (count < sizeof(header)) + return -EINVAL; + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &header, + 0, sizeof(header)); + if (ret) + goto out; + + /* + * Apart from PT_SVE_REGS_MASK, all PT_SVE_* flags are consumed by + * sve_set_vector_length(), which will also validate them for us: + */ + ret = sve_set_vector_length(target, header.vl, + ((unsigned long)header.flags & ~SVE_PT_REGS_MASK) << 16); + if (ret) + goto out; + + /* Actual VL set may be less than the user asked for: */ + vq = sve_vq_from_vl(target->thread.sve_vl); + + /* Registers: FPSIMD-only case */ + + BUILD_BUG_ON(SVE_PT_FPSIMD_OFFSET != sizeof(header)); + if ((header.flags & SVE_PT_REGS_MASK) == SVE_PT_REGS_FPSIMD) { + ret = __fpr_set(target, regset, pos, count, kbuf, ubuf, + SVE_PT_FPSIMD_OFFSET); + clear_tsk_thread_flag(target, TIF_SVE); + goto out; + } + + /* Otherwise: full SVE case */ + + /* + * If setting a different VL from the requested VL and there is + * register data, the data layout will be wrong: don't even + * try to set the registers in this case. + */ + if (count && vq != sve_vq_from_vl(header.vl)) { + ret = -EIO; + goto out; + } + + sve_alloc(target); + + /* + * Ensure target->thread.sve_state is up to date with target's + * FPSIMD regs, so that a short copyin leaves trailing registers + * unmodified. + */ + fpsimd_sync_to_sve(target); + set_tsk_thread_flag(target, TIF_SVE); + + BUILD_BUG_ON(SVE_PT_SVE_OFFSET != sizeof(header)); + start = SVE_PT_SVE_OFFSET; + end = SVE_PT_SVE_FFR_OFFSET(vq) + SVE_PT_SVE_FFR_SIZE(vq); + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, + target->thread.sve_state, + start, end); + if (ret) + goto out; + + start = end; + end = SVE_PT_SVE_FPSR_OFFSET(vq); + ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, + start, end); + if (ret) + goto out; + + /* + * Copy fpsr, and fpcr which must follow contiguously in + * struct fpsimd_state: + */ + start = end; + end = SVE_PT_SVE_FPCR_OFFSET(vq) + SVE_PT_SVE_FPCR_SIZE; + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, + &target->thread.uw.fpsimd_state.fpsr, + start, end); + +out: + fpsimd_flush_task_state(target); + return ret; +} + +#endif /* CONFIG_ARM64_SVE */ + +enum aarch64_regset { + REGSET_GPR, + REGSET_FPR, + REGSET_TLS, +#ifdef CONFIG_HAVE_HW_BREAKPOINT + REGSET_HW_BREAK, + REGSET_HW_WATCH, +#endif + REGSET_SYSTEM_CALL, +#ifdef CONFIG_ARM64_SVE + REGSET_SVE, +#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), + .active = fpr_active, + .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 + [REGSET_SYSTEM_CALL] = { + .core_note_type = NT_ARM_SYSTEM_CALL, + .n = 1, + .size = sizeof(int), + .align = sizeof(int), + .get = system_call_get, + .set = system_call_set, + }, +#ifdef CONFIG_ARM64_SVE + [REGSET_SVE] = { /* Scalable Vector Extension */ + .core_note_type = NT_ARM_SVE, + .n = DIV_ROUND_UP(SVE_PT_SIZE(SVE_VQ_MAX, SVE_PT_REGS_SVE), + SVE_VQ_BYTES), + .size = SVE_VQ_BYTES, + .align = SVE_VQ_BYTES, + .get = sve_get, + .set = sve_set, + .get_size = sve_get_size, + }, +#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 +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; + compat_ulong_t reg; + + switch (idx) { + case 15: + reg = task_pt_regs(target)->pc; + break; + case 16: + reg = task_pt_regs(target)->pstate; + reg = pstate_to_compat_psr(reg); + break; + case 17: + reg = task_pt_regs(target)->orig_x0; + break; + default: + reg = task_pt_regs(target)->regs[idx]; + } + + if (kbuf) { + memcpy(kbuf, ®, sizeof(reg)); + kbuf += sizeof(reg); + } else { + ret = copy_to_user(ubuf, ®, sizeof(reg)); + if (ret) { + ret = -EFAULT; + break; + } + + ubuf += sizeof(reg); + } + } + + 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; + compat_ulong_t reg; + + if (kbuf) { + memcpy(®, kbuf, sizeof(reg)); + kbuf += sizeof(reg); + } else { + ret = copy_from_user(®, ubuf, sizeof(reg)); + if (ret) { + ret = -EFAULT; + break; + } + + ubuf += sizeof(reg); + } + + switch (idx) { + case 15: + newregs.pc = reg; + break; + case 16: + reg = compat_psr_to_pstate(reg); + newregs.pstate = reg; + break; + case 17: + newregs.orig_x0 = reg; + break; + default: + newregs.regs[idx] = reg; + } + + } + + if (valid_user_regs(&newregs.user_regs, target)) + *task_pt_regs(target) = newregs; + else + ret = -EINVAL; + + 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, vregs_end_pos; + + if (!system_supports_fpsimd()) + return -EINVAL; + + uregs = &target->thread.uw.fpsimd_state; + + if (target == current) + fpsimd_preserve_current_state(); + + /* + * 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. + */ + vregs_end_pos = VFP_STATE_SIZE - sizeof(compat_ulong_t); + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, + 0, vregs_end_pos); + + if (count && !ret) { + fpscr = (uregs->fpsr & VFP_FPSCR_STAT_MASK) | + (uregs->fpcr & VFP_FPSCR_CTRL_MASK); + + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &fpscr, + vregs_end_pos, VFP_STATE_SIZE); + } + + 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, vregs_end_pos; + + if (!system_supports_fpsimd()) + return -EINVAL; + + uregs = &target->thread.uw.fpsimd_state; + + vregs_end_pos = VFP_STATE_SIZE - sizeof(compat_ulong_t); + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0, + vregs_end_pos); + + if (count && !ret) { + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpscr, + vregs_end_pos, VFP_STATE_SIZE); + if (!ret) { + uregs->fpsr = fpscr & VFP_FPSCR_STAT_MASK; + uregs->fpcr = fpscr & VFP_FPSCR_CTRL_MASK; + } + } + + fpsimd_flush_task_state(target); + return ret; +} + +static int compat_tls_get(struct task_struct *target, + const struct user_regset *regset, unsigned int pos, + unsigned int count, void *kbuf, void __user *ubuf) +{ + compat_ulong_t tls = (compat_ulong_t)target->thread.uw.tp_value; + return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &tls, 0, -1); +} + +static int compat_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; + compat_ulong_t tls = target->thread.uw.tp_value; + + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1); + if (ret) + return ret; + + target->thread.uw.tp_value = tls; + 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), + .active = fpr_active, + .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) +}; + +static const struct user_regset aarch32_ptrace_regsets[] = { + [REGSET_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_FPR] = { + .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 + }, + [REGSET_TLS] = { + .core_note_type = NT_ARM_TLS, + .n = 1, + .size = sizeof(compat_ulong_t), + .align = sizeof(compat_ulong_t), + .get = compat_tls_get, + .set = compat_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 + [REGSET_SYSTEM_CALL] = { + .core_note_type = NT_ARM_SYSTEM_CALL, + .n = 1, + .size = sizeof(int), + .align = sizeof(int), + .get = system_call_get, + .set = system_call_set, + }, +}; + +static const struct user_regset_view user_aarch32_ptrace_view = { + .name = "aarch32", .e_machine = EM_ARM, + .regsets = aarch32_ptrace_regsets, .n = ARRAY_SIZE(aarch32_ptrace_regsets) +}; + +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 == COMPAT_PT_TEXT_ADDR) + tmp = tsk->mm->start_code; + else if (off == COMPAT_PT_DATA_ADDR) + tmp = tsk->mm->start_data; + else if (off == COMPAT_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; + mm_segment_t old_fs = get_fs(); + + if (off & 3 || off >= COMPAT_USER_SZ) + return -EIO; + + if (off >= sizeof(compat_elf_gregset_t)) + return 0; + + set_fs(KERNEL_DS); + ret = copy_regset_from_user(tsk, &user_aarch32_view, + REGSET_COMPAT_GPR, off, + sizeof(compat_ulong_t), + &val); + set_fs(old_fs); + + 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; + + /* 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); + } + + 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; + + if (num == 0) + return 0; + + ret = get_user(kdata, data); + if (ret) + return ret; + + 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); + + 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 COMPAT_PTRACE_GETREGS: + ret = copy_regset_to_user(child, + &user_aarch32_view, + REGSET_COMPAT_GPR, + 0, sizeof(compat_elf_gregset_t), + datap); + break; + + case COMPAT_PTRACE_SETREGS: + ret = copy_regset_from_user(child, + &user_aarch32_view, + REGSET_COMPAT_GPR, + 0, sizeof(compat_elf_gregset_t), + datap); + break; + + case COMPAT_PTRACE_GET_THREAD_AREA: + ret = put_user((compat_ulong_t)child->thread.uw.tp_value, + (compat_ulong_t __user *)datap); + break; + + case COMPAT_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 COMPAT_PTRACE_GETHBPREGS: + ret = compat_ptrace_gethbpregs(child, addr, datap); + break; + + case COMPAT_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 + /* + * Core dumping of 32-bit tasks or compat ptrace requests must use the + * user_aarch32_view compatible with arm32. Native ptrace requests on + * 32-bit children use an extended user_aarch32_ptrace_view to allow + * access to the TLS register. + */ + if (is_compat_task()) + return &user_aarch32_view; + else if (is_compat_thread(task_thread_info(task))) + return &user_aarch32_ptrace_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); +} + +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) +{ + int regno; + unsigned long saved_reg; + + /* + * A scratch register (ip(r12) on AArch32, x7 on AArch64) is + * used to denote syscall entry/exit: + */ + regno = (is_compat_task() ? 12 : 7); + saved_reg = regs->regs[regno]; + regs->regs[regno] = dir; + + if (dir == PTRACE_SYSCALL_ENTER) { + if (tracehook_report_syscall_entry(regs)) + forget_syscall(regs); + regs->regs[regno] = saved_reg; + } else if (!test_thread_flag(TIF_SINGLESTEP)) { + tracehook_report_syscall_exit(regs, 0); + regs->regs[regno] = saved_reg; + } else { + regs->regs[regno] = saved_reg; + + /* + * Signal a pseudo-step exception since we are stepping but + * tracer modifications to the registers may have rewound the + * state machine. + */ + tracehook_report_syscall_exit(regs, 1); + } +} + +int syscall_trace_enter(struct pt_regs *regs) +{ + if (test_thread_flag(TIF_SYSCALL_TRACE)) + tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER); + + /* Do the secure computing after ptrace; failures should be fast. */ + if (secure_computing(NULL) == -1) + return -1; + + if (test_thread_flag(TIF_SYSCALL_TRACEPOINT)) + trace_sys_enter(regs, regs->syscallno); + + audit_syscall_entry(regs->syscallno, regs->orig_x0, regs->regs[1], + regs->regs[2], regs->regs[3]); + + return regs->syscallno; +} + +void syscall_trace_exit(struct pt_regs *regs) +{ + unsigned long flags = READ_ONCE(current_thread_info()->flags); + + audit_syscall_exit(regs); + + if (flags & _TIF_SYSCALL_TRACEPOINT) + trace_sys_exit(regs, regs_return_value(regs)); + + if (flags & (_TIF_SYSCALL_TRACE | _TIF_SINGLESTEP)) + tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT); + + rseq_syscall(regs); +} + +/* + * SPSR_ELx bits which are always architecturally RES0 per ARM DDI 0487D.a. + * We permit userspace to set SSBS (AArch64 bit 12, AArch32 bit 23) which is + * not described in ARM DDI 0487D.a. + * We treat PAN and UAO as RES0 bits, as they are meaningless at EL0, and may + * be allocated an EL0 meaning in future. + * Userspace cannot use these until they have an architectural meaning. + * Note that this follows the SPSR_ELx format, not the AArch32 PSR format. + * We also reserve IL for the kernel; SS is handled dynamically. + */ +#define SPSR_EL1_AARCH64_RES0_BITS \ + (GENMASK_ULL(63, 32) | GENMASK_ULL(27, 25) | GENMASK_ULL(23, 22) | \ + GENMASK_ULL(20, 13) | GENMASK_ULL(11, 10) | GENMASK_ULL(5, 5)) +#define SPSR_EL1_AARCH32_RES0_BITS \ + (GENMASK_ULL(63, 32) | GENMASK_ULL(22, 22) | GENMASK_ULL(20, 20)) + +static int valid_compat_regs(struct user_pt_regs *regs) +{ + regs->pstate &= ~SPSR_EL1_AARCH32_RES0_BITS; + + if (!system_supports_mixed_endian_el0()) { + if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)) + regs->pstate |= PSR_AA32_E_BIT; + else + regs->pstate &= ~PSR_AA32_E_BIT; + } + + if (user_mode(regs) && (regs->pstate & PSR_MODE32_BIT) && + (regs->pstate & PSR_AA32_A_BIT) == 0 && + (regs->pstate & PSR_AA32_I_BIT) == 0 && + (regs->pstate & PSR_AA32_F_BIT) == 0) { + return 1; + } + + /* + * Force PSR to a valid 32-bit EL0t, preserving the same bits as + * arch/arm. + */ + regs->pstate &= PSR_AA32_N_BIT | PSR_AA32_Z_BIT | + PSR_AA32_C_BIT | PSR_AA32_V_BIT | + PSR_AA32_Q_BIT | PSR_AA32_IT_MASK | + PSR_AA32_GE_MASK | PSR_AA32_E_BIT | + PSR_AA32_T_BIT; + regs->pstate |= PSR_MODE32_BIT; + + return 0; +} + +static int valid_native_regs(struct user_pt_regs *regs) +{ + regs->pstate &= ~SPSR_EL1_AARCH64_RES0_BITS; + + if (user_mode(regs) && !(regs->pstate & PSR_MODE32_BIT) && + (regs->pstate & PSR_D_BIT) == 0 && + (regs->pstate & PSR_A_BIT) == 0 && + (regs->pstate & PSR_I_BIT) == 0 && + (regs->pstate & PSR_F_BIT) == 0) { + return 1; + } + + /* Force PSR to a valid 64-bit EL0t */ + regs->pstate &= PSR_N_BIT | PSR_Z_BIT | PSR_C_BIT | PSR_V_BIT; + + return 0; +} + +/* + * Are the current registers suitable for user mode? (used to maintain + * security in signal handlers) + */ +int valid_user_regs(struct user_pt_regs *regs, struct task_struct *task) +{ + /* https://lore.kernel.org/lkml/20191118131525.GA4180@willie-the-truck */ + user_regs_reset_single_step(regs, task); + + if (is_compat_thread(task_thread_info(task))) + return valid_compat_regs(regs); + else + return valid_native_regs(regs); +} |