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Diffstat (limited to 'arch/loongarch/kernel/ptrace.c')
| -rw-r--r-- | arch/loongarch/kernel/ptrace.c | 433 |
1 files changed, 433 insertions, 0 deletions
diff --git a/arch/loongarch/kernel/ptrace.c b/arch/loongarch/kernel/ptrace.c new file mode 100644 index 000000000..dc2b82ea8 --- /dev/null +++ b/arch/loongarch/kernel/ptrace.c @@ -0,0 +1,433 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Author: Hanlu Li <lihanlu@loongson.cn> + * Huacai Chen <chenhuacai@loongson.cn> + * + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited + * + * Derived from MIPS: + * Copyright (C) 1992 Ross Biro + * Copyright (C) Linus Torvalds + * Copyright (C) 1994, 95, 96, 97, 98, 2000 Ralf Baechle + * Copyright (C) 1996 David S. Miller + * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com + * Copyright (C) 1999 MIPS Technologies, Inc. + * Copyright (C) 2000 Ulf Carlsson + */ +#include <linux/kernel.h> +#include <linux/audit.h> +#include <linux/compiler.h> +#include <linux/context_tracking.h> +#include <linux/elf.h> +#include <linux/errno.h> +#include <linux/mm.h> +#include <linux/ptrace.h> +#include <linux/regset.h> +#include <linux/sched.h> +#include <linux/sched/task_stack.h> +#include <linux/security.h> +#include <linux/smp.h> +#include <linux/stddef.h> +#include <linux/seccomp.h> +#include <linux/uaccess.h> + +#include <asm/byteorder.h> +#include <asm/cpu.h> +#include <asm/cpu-info.h> +#include <asm/fpu.h> +#include <asm/loongarch.h> +#include <asm/page.h> +#include <asm/pgtable.h> +#include <asm/processor.h> +#include <asm/reg.h> +#include <asm/syscall.h> + +static void init_fp_ctx(struct task_struct *target) +{ + /* The target already has context */ + if (tsk_used_math(target)) + return; + + /* Begin with data registers set to all 1s... */ + memset(&target->thread.fpu.fpr, ~0, sizeof(target->thread.fpu.fpr)); + set_stopped_child_used_math(target); +} + +/* + * Called by kernel/ptrace.c when detaching.. + * + * Make sure single step bits etc are not set. + */ +void ptrace_disable(struct task_struct *child) +{ + /* Don't load the watchpoint registers for the ex-child. */ + clear_tsk_thread_flag(child, TIF_LOAD_WATCH); + clear_tsk_thread_flag(child, TIF_SINGLESTEP); +} + +/* regset get/set implementations */ + +static int gpr_get(struct task_struct *target, + const struct user_regset *regset, + struct membuf to) +{ + int r; + struct pt_regs *regs = task_pt_regs(target); + + r = membuf_write(&to, ®s->regs, sizeof(u64) * GPR_NUM); + r = membuf_write(&to, ®s->orig_a0, sizeof(u64)); + r = membuf_write(&to, ®s->csr_era, sizeof(u64)); + r = membuf_write(&to, ®s->csr_badvaddr, sizeof(u64)); + + return r; +} + +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 err; + int a0_start = sizeof(u64) * GPR_NUM; + int era_start = a0_start + sizeof(u64); + int badvaddr_start = era_start + sizeof(u64); + struct pt_regs *regs = task_pt_regs(target); + + err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, + ®s->regs, + 0, a0_start); + err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf, + ®s->orig_a0, + a0_start, a0_start + sizeof(u64)); + err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf, + ®s->csr_era, + era_start, era_start + sizeof(u64)); + err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf, + ®s->csr_badvaddr, + badvaddr_start, badvaddr_start + sizeof(u64)); + + return err; +} + + +/* + * Get the general floating-point registers. + */ +static int gfpr_get(struct task_struct *target, struct membuf *to) +{ + return membuf_write(to, &target->thread.fpu.fpr, + sizeof(elf_fpreg_t) * NUM_FPU_REGS); +} + +static int gfpr_get_simd(struct task_struct *target, struct membuf *to) +{ + int i, r; + u64 fpr_val; + + BUILD_BUG_ON(sizeof(fpr_val) != sizeof(elf_fpreg_t)); + for (i = 0; i < NUM_FPU_REGS; i++) { + fpr_val = get_fpr64(&target->thread.fpu.fpr[i], 0); + r = membuf_write(to, &fpr_val, sizeof(elf_fpreg_t)); + } + + return r; +} + +/* + * Choose the appropriate helper for general registers, and then copy + * the FCC and FCSR registers separately. + */ +static int fpr_get(struct task_struct *target, + const struct user_regset *regset, + struct membuf to) +{ + int r; + + if (sizeof(target->thread.fpu.fpr[0]) == sizeof(elf_fpreg_t)) + r = gfpr_get(target, &to); + else + r = gfpr_get_simd(target, &to); + + r = membuf_write(&to, &target->thread.fpu.fcc, sizeof(target->thread.fpu.fcc)); + r = membuf_write(&to, &target->thread.fpu.fcsr, sizeof(target->thread.fpu.fcsr)); + + return r; +} + +static int gfpr_set(struct task_struct *target, + unsigned int *pos, unsigned int *count, + const void **kbuf, const void __user **ubuf) +{ + return user_regset_copyin(pos, count, kbuf, ubuf, + &target->thread.fpu.fpr, + 0, NUM_FPU_REGS * sizeof(elf_fpreg_t)); +} + +static int gfpr_set_simd(struct task_struct *target, + unsigned int *pos, unsigned int *count, + const void **kbuf, const void __user **ubuf) +{ + int i, err; + u64 fpr_val; + + BUILD_BUG_ON(sizeof(fpr_val) != sizeof(elf_fpreg_t)); + for (i = 0; i < NUM_FPU_REGS && *count > 0; i++) { + err = user_regset_copyin(pos, count, kbuf, ubuf, + &fpr_val, i * sizeof(elf_fpreg_t), + (i + 1) * sizeof(elf_fpreg_t)); + if (err) + return err; + set_fpr64(&target->thread.fpu.fpr[i], 0, fpr_val); + } + + return 0; +} + +/* + * Choose the appropriate helper for general registers, and then copy + * the FCC register separately. + */ +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) +{ + const int fcc_start = NUM_FPU_REGS * sizeof(elf_fpreg_t); + const int fcsr_start = fcc_start + sizeof(u64); + int err; + + BUG_ON(count % sizeof(elf_fpreg_t)); + if (pos + count > sizeof(elf_fpregset_t)) + return -EIO; + + init_fp_ctx(target); + + if (sizeof(target->thread.fpu.fpr[0]) == sizeof(elf_fpreg_t)) + err = gfpr_set(target, &pos, &count, &kbuf, &ubuf); + else + err = gfpr_set_simd(target, &pos, &count, &kbuf, &ubuf); + if (err) + return err; + + err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf, + &target->thread.fpu.fcc, fcc_start, + fcc_start + sizeof(u64)); + err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf, + &target->thread.fpu.fcsr, fcsr_start, + fcsr_start + sizeof(u32)); + + return err; +} + +static int cfg_get(struct task_struct *target, + const struct user_regset *regset, + struct membuf to) +{ + int i, r; + u32 cfg_val; + + i = 0; + while (to.left > 0) { + cfg_val = read_cpucfg(i++); + r = membuf_write(&to, &cfg_val, sizeof(u32)); + } + + return r; +} + +/* + * CFG registers are read-only. + */ +static int cfg_set(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + const void *kbuf, const void __user *ubuf) +{ + return 0; +} + +struct pt_regs_offset { + const char *name; + int offset; +}; + +#define REG_OFFSET_NAME(n, r) {.name = #n, .offset = offsetof(struct pt_regs, r)} +#define REG_OFFSET_END {.name = NULL, .offset = 0} + +static const struct pt_regs_offset regoffset_table[] = { + REG_OFFSET_NAME(r0, regs[0]), + REG_OFFSET_NAME(r1, regs[1]), + REG_OFFSET_NAME(r2, regs[2]), + REG_OFFSET_NAME(r3, regs[3]), + REG_OFFSET_NAME(r4, regs[4]), + REG_OFFSET_NAME(r5, regs[5]), + REG_OFFSET_NAME(r6, regs[6]), + REG_OFFSET_NAME(r7, regs[7]), + REG_OFFSET_NAME(r8, regs[8]), + REG_OFFSET_NAME(r9, regs[9]), + REG_OFFSET_NAME(r10, regs[10]), + REG_OFFSET_NAME(r11, regs[11]), + REG_OFFSET_NAME(r12, regs[12]), + REG_OFFSET_NAME(r13, regs[13]), + REG_OFFSET_NAME(r14, regs[14]), + REG_OFFSET_NAME(r15, regs[15]), + REG_OFFSET_NAME(r16, regs[16]), + REG_OFFSET_NAME(r17, regs[17]), + REG_OFFSET_NAME(r18, regs[18]), + REG_OFFSET_NAME(r19, regs[19]), + REG_OFFSET_NAME(r20, regs[20]), + REG_OFFSET_NAME(r21, regs[21]), + REG_OFFSET_NAME(r22, regs[22]), + REG_OFFSET_NAME(r23, regs[23]), + REG_OFFSET_NAME(r24, regs[24]), + REG_OFFSET_NAME(r25, regs[25]), + REG_OFFSET_NAME(r26, regs[26]), + REG_OFFSET_NAME(r27, regs[27]), + REG_OFFSET_NAME(r28, regs[28]), + REG_OFFSET_NAME(r29, regs[29]), + REG_OFFSET_NAME(r30, regs[30]), + REG_OFFSET_NAME(r31, regs[31]), + REG_OFFSET_NAME(orig_a0, orig_a0), + REG_OFFSET_NAME(csr_era, csr_era), + REG_OFFSET_NAME(csr_badvaddr, csr_badvaddr), + REG_OFFSET_NAME(csr_crmd, csr_crmd), + REG_OFFSET_NAME(csr_prmd, csr_prmd), + REG_OFFSET_NAME(csr_euen, csr_euen), + REG_OFFSET_NAME(csr_ecfg, csr_ecfg), + REG_OFFSET_NAME(csr_estat, csr_estat), + 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; +} + +enum loongarch_regset { + REGSET_GPR, + REGSET_FPR, + REGSET_CPUCFG, +}; + +static const struct user_regset loongarch64_regsets[] = { + [REGSET_GPR] = { + .core_note_type = NT_PRSTATUS, + .n = ELF_NGREG, + .size = sizeof(elf_greg_t), + .align = sizeof(elf_greg_t), + .regset_get = gpr_get, + .set = gpr_set, + }, + [REGSET_FPR] = { + .core_note_type = NT_PRFPREG, + .n = ELF_NFPREG, + .size = sizeof(elf_fpreg_t), + .align = sizeof(elf_fpreg_t), + .regset_get = fpr_get, + .set = fpr_set, + }, + [REGSET_CPUCFG] = { + .core_note_type = NT_LOONGARCH_CPUCFG, + .n = 64, + .size = sizeof(u32), + .align = sizeof(u32), + .regset_get = cfg_get, + .set = cfg_set, + }, +}; + +static const struct user_regset_view user_loongarch64_view = { + .name = "loongarch64", + .e_machine = ELF_ARCH, + .regsets = loongarch64_regsets, + .n = ARRAY_SIZE(loongarch64_regsets), +}; + + +const struct user_regset_view *task_user_regset_view(struct task_struct *task) +{ + return &user_loongarch64_view; +} + +static inline int read_user(struct task_struct *target, unsigned long addr, + unsigned long __user *data) +{ + unsigned long tmp = 0; + + switch (addr) { + case 0 ... 31: + tmp = task_pt_regs(target)->regs[addr]; + break; + case ARG0: + tmp = task_pt_regs(target)->orig_a0; + break; + case PC: + tmp = task_pt_regs(target)->csr_era; + break; + case BADVADDR: + tmp = task_pt_regs(target)->csr_badvaddr; + break; + default: + return -EIO; + } + + return put_user(tmp, data); +} + +static inline int write_user(struct task_struct *target, unsigned long addr, + unsigned long data) +{ + switch (addr) { + case 0 ... 31: + task_pt_regs(target)->regs[addr] = data; + break; + case ARG0: + task_pt_regs(target)->orig_a0 = data; + break; + case PC: + task_pt_regs(target)->csr_era = data; + break; + case BADVADDR: + task_pt_regs(target)->csr_badvaddr = data; + break; + default: + return -EIO; + } + + return 0; +} + +long arch_ptrace(struct task_struct *child, long request, + unsigned long addr, unsigned long data) +{ + int ret; + unsigned long __user *datap = (void __user *) data; + + switch (request) { + case PTRACE_PEEKUSR: + ret = read_user(child, addr, datap); + break; + + case PTRACE_POKEUSR: + ret = write_user(child, addr, data); + break; + + default: + ret = ptrace_request(child, request, addr, data); + break; + } + + return ret; +} |