// SPDX-License-Identifier: GPL-2.0/* ptrace.c *//* By Ross Biro 1/23/92 *//* edited by Linus Torvalds *//* mangled further by Bob Manson (manson@santafe.edu) *//* more mutilation by David Mosberger (davidm@azstarnet.com) */ #include <linux/kernel.h>#include <linux/sched.h>#include <linux/sched/task_stack.h>#include <linux/mm.h>#include <linux/smp.h>#include <linux/errno.h>#include <linux/ptrace.h>#include <linux/user.h>#include <linux/security.h>#include <linux/signal.h>#include <linux/audit.h>#include <linux/seccomp.h>#include <asm/syscall.h> #include <linux/uaccess.h>#include <asm/fpu.h> #include "proto.h"#include <linux/uio.h>#include <linux/regset.h> #define DEBUG DBG_MEM#undef DEBUG #ifndef NT_FPREGSET#define NT_FPREGSET NT_PRFPREG#endif #ifdef DEBUGenum { DBG_MEM = (1<<0), DBG_BPT = (1<<1), DBG_MEM_ALL = (1<<2)};#define DBG(fac,args) {if ((fac) & DEBUG) printk args;}#else#define DBG(fac,args)#endif #define BREAKINST 0x00000080 /* call_pal bpt */ /* * does not yet catch signals sent when the child dies. * in exit.c or in signal.c. */ /* * Processes always block with the following stack-layout: * * +================================+ <---- task + 2*PAGE_SIZE * | PALcode saved frame (ps, pc, | ^ * | gp, a0, a1, a2) | | * +================================+ | struct pt_regs * | | | * | frame generated by SAVE_ALL | | * | | v * +================================+ * | | ^ * | frame saved by do_switch_stack | | struct switch_stack * | | v * +================================+ */ /* * The following table maps a register index into the stack offset at * which the register is saved. Register indices are 0-31 for integer * regs, 32-63 for fp regs, and 64 for the pc. Notice that sp and * zero have no stack-slot and need to be treated specially (see * get_reg/put_reg below). */enum { REG_R0 = 0, REG_F0 = 32, REG_FPCR = 63, REG_PC = 64}; #define PT_REG(reg) \ (PAGE_SIZE*2 - sizeof(struct pt_regs) + offsetof(struct pt_regs, reg)) #define SW_REG(reg) \ (PAGE_SIZE*2 - sizeof(struct pt_regs) - sizeof(struct switch_stack) \ + offsetof(struct switch_stack, reg)) #define FP_REG(reg) (offsetof(struct thread_info, reg)) static int regoff[] = { PT_REG( r0), PT_REG( r1), PT_REG( r2), PT_REG( r3), PT_REG( r4), PT_REG( r5), PT_REG( r6), PT_REG( r7), PT_REG( r8), SW_REG( r9), SW_REG( r10), SW_REG( r11), SW_REG( r12), SW_REG( r13), SW_REG( r14), SW_REG( r15), PT_REG( r16), PT_REG( r17), PT_REG( r18), PT_REG( r19), PT_REG( r20), PT_REG( r21), PT_REG( r22), PT_REG( r23), PT_REG( r24), PT_REG( r25), PT_REG( r26), PT_REG( r27), PT_REG( r28), PT_REG( gp), -1, -1, FP_REG(fp[ 0]), FP_REG(fp[ 1]), FP_REG(fp[ 2]), FP_REG(fp[ 3]), FP_REG(fp[ 4]), FP_REG(fp[ 5]), FP_REG(fp[ 6]), FP_REG(fp[ 7]), FP_REG(fp[ 8]), FP_REG(fp[ 9]), FP_REG(fp[10]), FP_REG(fp[11]), FP_REG(fp[12]), FP_REG(fp[13]), FP_REG(fp[14]), FP_REG(fp[15]), FP_REG(fp[16]), FP_REG(fp[17]), FP_REG(fp[18]), FP_REG(fp[19]), FP_REG(fp[20]), FP_REG(fp[21]), FP_REG(fp[22]), FP_REG(fp[23]), FP_REG(fp[24]), FP_REG(fp[25]), FP_REG(fp[26]), FP_REG(fp[27]), FP_REG(fp[28]), FP_REG(fp[29]), FP_REG(fp[30]), FP_REG(fp[31]), PT_REG( pc)}; static unsigned long zero; /* * Get address of register REGNO in task TASK. */static unsigned long *get_reg_addr(struct task_struct * task, unsigned long regno){ unsigned long *addr; if (regno == 30) { addr = &task_thread_info(task)->pcb.usp; } else if (regno == 65) { addr = &task_thread_info(task)->pcb.unique; } else if (regno == 31 || regno > 65) { zero = 0; addr = &zero; } else { addr = task_stack_page(task) + regoff[regno]; } return addr;} /* * Get contents of register REGNO in task TASK. */static unsigned longget_reg(struct task_struct * task, unsigned long regno){ /* Special hack for fpcr -- combine hardware and software bits. */ if (regno == 63) { unsigned long fpcr = *get_reg_addr(task, regno); unsigned long swcr = task_thread_info(task)->ieee_state & IEEE_SW_MASK; swcr = swcr_update_status(swcr, fpcr); return fpcr | swcr; } return *get_reg_addr(task, regno);} static void alpha_elf_fpregs_get(struct task_struct *target, elf_fpreg_t *fpregs) /* points to ELF_NFPREG entries */{ memcpy(fpregs, task_thread_info(target)->fp, sizeof(elf_fpregset_t));} static void alpha_elf_fpregs_set(struct task_struct *target, const elf_fpreg_t *fpregs, size_t nwords){ size_t n = min_t(size_t, nwords, ELF_NFPREG); memcpy(task_thread_info(target)->fp, fpregs, n * sizeof(elf_fpreg_t));} static void alpha_elf_gregs_set(struct task_struct *child, const elf_greg_t *src, size_t nwords){ struct pt_regs *pt = task_pt_regs(child); struct thread_info *ti = task_thread_info(child); struct switch_stack *sw = ((struct switch_stack *)pt) - 1; /* GPRs r0..r8 live in pt_regs */ if (nwords > 0) pt->r0 = src[0]; if (nwords > 1) pt->r1 = src[1]; if (nwords > 2) pt->r2 = src[2]; if (nwords > 3) pt->r3 = src[3]; if (nwords > 4) pt->r4 = src[4]; if (nwords > 5) pt->r5 = src[5]; if (nwords > 6) pt->r6 = src[6]; if (nwords > 7) pt->r7 = src[7]; if (nwords > 8) pt->r8 = src[8]; /* r9..r15 live in switch_stack */ if (nwords > 9) sw->r9 = src[9]; if (nwords > 10) sw->r10 = src[10]; if (nwords > 11) sw->r11 = src[11]; if (nwords > 12) sw->r12 = src[12]; if (nwords > 13) sw->r13 = src[13]; if (nwords > 14) sw->r14 = src[14]; if (nwords > 15) sw->r15 = src[15]; /* r16..r28 live in pt_regs */ if (nwords > 16) pt->r16 = src[16]; if (nwords > 17) pt->r17 = src[17]; if (nwords > 18) pt->r18 = src[18]; if (nwords > 19) pt->r19 = src[19]; if (nwords > 20) pt->r20 = src[20]; if (nwords > 21) pt->r21 = src[21]; if (nwords > 22) pt->r22 = src[22]; if (nwords > 23) pt->r23 = src[23]; if (nwords > 24) pt->r24 = src[24]; if (nwords > 25) pt->r25 = src[25]; if (nwords > 26) pt->r26 = src[26]; if (nwords > 27) pt->r27 = src[27]; if (nwords > 28) pt->r28 = src[28]; /* gp, usp, pc, unique */ if (nwords > 29) pt->gp = src[29]; if (nwords > 30) { ti->pcb.usp = src[30]; /* * If someone ever does this to current (rare), keep the * hardware usp consistent. */ if (child == current) wrusp(src[30]); } if (nwords > 31) pt->pc = src[31]; if (nwords > 32) ti->pcb.unique = src[32]; /* * PTRACE_SETREGSET can be used at a syscall-entry stop to skip the * syscall by setting the syscall number to -1. The seccomp/ptrace * selftests use this to synthesize errno returns. * * Alpha uses r19/a3 as the error flag, so a skipped syscall with a * small positive r0 and a clear r19 must be normalized to an error * return. */ if (pt->r1 == (unsigned long)-1 && pt->r19 == 0 && pt->r0 > 0 && pt->r0 < MAX_ERRNO) pt->r19 = 1;} /* * Write contents of register REGNO in task TASK. */static intput_reg(struct task_struct *task, unsigned long regno, unsigned long data){ struct pt_regs *regs = task_pt_regs(task); if (regno == 63) { task_thread_info(task)->ieee_state = ((task_thread_info(task)->ieee_state & ~IEEE_SW_MASK) | (data & IEEE_SW_MASK)); data = (data & FPCR_DYN_MASK) | ieee_swcr_to_fpcr(data); } *get_reg_addr(task, regno) = data; /* * Alpha historically exposes r0/v0 as the syscall number at a * syscall-entry stop. The generic-entry conversion keeps the * mutable syscall number in regs->r1, so old ptrace users such * as strace that skip a syscall by poking r0 to -1 must also * update the internal shadow syscall number. * * Do not mirror other r0 writes. strace later pokes r0 to the * injected return value, e.g. 42, while r1 must remain -1. */ if (regno == 0 && data == (unsigned long)-1) { regs->r1 = data; regs->r19 = 0; } return 0;} static inline intread_int(struct task_struct *task, unsigned long addr, int * data){ int copied = access_process_vm(task, addr, data, sizeof(int), FOLL_FORCE); return (copied == sizeof(int)) ? 0 : -EIO;} static inline intwrite_int(struct task_struct *task, unsigned long addr, int data){ int copied = access_process_vm(task, addr, &data, sizeof(int), FOLL_FORCE | FOLL_WRITE); return (copied == sizeof(int)) ? 0 : -EIO;} /* * Set breakpoint. */intptrace_set_bpt(struct task_struct * child){ int displ, i, res, reg_b, nsaved = 0; unsigned int insn, op_code; unsigned long pc; pc = get_reg(child, REG_PC); res = read_int(child, pc, (int *) &insn); if (res < 0) return res; op_code = insn >> 26; if (op_code >= 0x30) { /* * It's a branch: instead of trying to figure out * whether the branch will be taken or not, we'll put * a breakpoint at either location. This is simpler, * more reliable, and probably not a whole lot slower * than the alternative approach of emulating the * branch (emulation can be tricky for fp branches). */ displ = ((s32)(insn << 11)) >> 9; task_thread_info(child)->bpt_addr[nsaved++] = pc + 4; if (displ) /* guard against unoptimized code */ task_thread_info(child)->bpt_addr[nsaved++] = pc + 4 + displ; DBG(DBG_BPT, ("execing branch\n")); } else if (op_code == 0x1a) { reg_b = (insn >> 16) & 0x1f; task_thread_info(child)->bpt_addr[nsaved++] = get_reg(child, reg_b); DBG(DBG_BPT, ("execing jump\n")); } else { task_thread_info(child)->bpt_addr[nsaved++] = pc + 4; DBG(DBG_BPT, ("execing normal insn\n")); } /* install breakpoints: */ for (i = 0; i < nsaved; ++i) { res = read_int(child, task_thread_info(child)->bpt_addr[i], (int *) &insn); if (res < 0) return res; task_thread_info(child)->bpt_insn[i] = insn; DBG(DBG_BPT, (" -> next_pc=%lx\n", task_thread_info(child)->bpt_addr[i])); res = write_int(child, task_thread_info(child)->bpt_addr[i], BREAKINST); if (res < 0) return res; } task_thread_info(child)->bpt_nsaved = nsaved; return 0;} /* * Ensure no single-step breakpoint is pending. Returns non-zero * value if child was being single-stepped. */intptrace_cancel_bpt(struct task_struct * child){ int i, nsaved = task_thread_info(child)->bpt_nsaved; task_thread_info(child)->bpt_nsaved = 0; if (nsaved > 2) { printk("ptrace_cancel_bpt: bogus nsaved: %d!\n", nsaved); nsaved = 2; } for (i = 0; i < nsaved; ++i) { write_int(child, task_thread_info(child)->bpt_addr[i], task_thread_info(child)->bpt_insn[i]); } return (nsaved != 0);} void user_enable_single_step(struct task_struct *child){ /* Mark single stepping. */ task_thread_info(child)->bpt_nsaved = -1;} void user_disable_single_step(struct task_struct *child){ ptrace_cancel_bpt(child);} /* * Called by kernel/ptrace.c when detaching.. * * Make sure the single step bit is not set. */void ptrace_disable(struct task_struct *child){ user_disable_single_step(child);} long arch_ptrace(struct task_struct *child, long request, unsigned long addr, unsigned long data){ unsigned long tmp; size_t copied; long ret; switch (request) { /* When I and D space are separate, these will need to be fixed. */ case PTRACE_PEEKTEXT: /* read word at location addr. */ case PTRACE_PEEKDATA: copied = ptrace_access_vm(child, addr, &tmp, sizeof(tmp), FOLL_FORCE); ret = -EIO; if (copied != sizeof(tmp)) break; force_successful_syscall_return(); ret = tmp; break; /* Read register number ADDR. */ case PTRACE_PEEKUSR: force_successful_syscall_return(); ret = get_reg(child, addr); DBG(DBG_MEM, ("peek $%lu->%#lx\n", addr, ret)); break; /* When I and D space are separate, this will have to be fixed. */ case PTRACE_POKETEXT: /* write the word at location addr. */ case PTRACE_POKEDATA: ret = generic_ptrace_pokedata(child, addr, data); break; case PTRACE_POKEUSR: /* write the specified register */ DBG(DBG_MEM, ("poke $%lu<-%#lx\n", addr, data)); ret = put_reg(child, addr, data); break; default: ret = ptrace_request(child, request, addr, data); break; } return ret;} asmlinkage unsigned long syscall_trace_enter(void){ struct pt_regs *regs = current_pt_regs(); if (test_thread_flag(TIF_SYSCALL_TRACE) && !ptrace_report_syscall_permit_entry(regs)) { syscall_set_nr(current, regs, -1); if (regs->r19 == 0 && regs->r0 == (unsigned long)-1) syscall_set_return_value(current, regs, -ENOSYS, 0); return -1UL; } /* * Do the secure computing after ptrace; failures should be fast. * If this fails, seccomp may already have set up the return value * (e.g. SECCOMP_RET_ERRNO / TRACE). */ if (!seccomp_permit_syscall()) { if (regs->r19 == 0 && regs->r0 == (unsigned long)-1) syscall_set_return_value(current, regs, -ENOSYS, 0); syscall_set_nr(current, regs, -1); return -1UL; } #ifdef CONFIG_AUDITSYSCALL audit_syscall_entry(syscall_get_nr(current, regs), regs->r16, regs->r17, regs->r18, regs->r19);Lines 1–500 of 636. 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// SPDX-License-Identifier: GPL-2.0 /* ptrace.c */ /* By Ross Biro 1/23/92 */ /* edited by Linus Torvalds */ /* mangled further by Bob Manson (manson@santafe.edu) */ /* more mutilation by David Mosberger (davidm@azstarnet.com) */ #include <linux/kernel.h> #include <linux/sched.h> #include <linux/sched/task_stack.h> #include <linux/mm.h> #include <linux/smp.h> #include <linux/errno.h> #include <linux/ptrace.h> #include <linux/user.h> #include <linux/security.h> #include <linux/signal.h> #include <linux/audit.h> #include <linux/seccomp.h> #include <asm/syscall.h> #include <linux/uaccess.h> #include <asm/fpu.h> #include "proto.h" #include <linux/uio.h> #include <linux/regset.h> #define DEBUG DBG_MEM #undef DEBUG #ifndef NT_FPREGSET #define NT_FPREGSET NT_PRFPREG #endif #ifdef DEBUG enum { DBG_MEM = (1<<0), DBG_BPT = (1<<1), DBG_MEM_ALL = (1<<2) }; #define DBG(fac,args) {if ((fac) & DEBUG) printk args;} #else #define DBG(fac,args) #endif #define BREAKINST 0x00000080 /* call_pal bpt */ /* * does not yet catch signals sent when the child dies. * in exit.c or in signal.c. */ /* * Processes always block with the following stack-layout: * * +================================+ <---- task + 2*PAGE_SIZE * | PALcode saved frame (ps, pc, | ^ * | gp, a0, a1, a2) | | * +================================+ | struct pt_regs * | | | * | frame generated by SAVE_ALL | | * | | v * +================================+ * | | ^ * | frame saved by do_switch_stack | | struct switch_stack * | | v * +================================+ */ /* * The following table maps a register index into the stack offset at * which the register is saved. Register indices are 0-31 for integer * regs, 32-63 for fp regs, and 64 for the pc. Notice that sp and * zero have no stack-slot and need to be treated specially (see * get_reg/put_reg below). */ enum { REG_R0 = 0, REG_F0 = 32, REG_FPCR = 63, REG_PC = 64 }; #define PT_REG(reg) \ (PAGE_SIZE*2 - sizeof(struct pt_regs) + offsetof(struct pt_regs, reg)) #define SW_REG(reg) \ (PAGE_SIZE*2 - sizeof(struct pt_regs) - sizeof(struct switch_stack) \ + offsetof(struct switch_stack, reg)) #define FP_REG(reg) (offsetof(struct thread_info, reg)) static int regoff[] = { PT_REG( r0), PT_REG( r1), PT_REG( r2), PT_REG( r3), PT_REG( r4), PT_REG( r5), PT_REG( r6), PT_REG( r7), PT_REG( r8), SW_REG( r9), SW_REG( r10), SW_REG( r11), SW_REG( r12), SW_REG( r13), SW_REG( r14), SW_REG( r15), PT_REG( r16), PT_REG( r17), PT_REG( r18), PT_REG( r19), PT_REG( r20), PT_REG( r21), PT_REG( r22), PT_REG( r23), PT_REG( r24), PT_REG( r25), PT_REG( r26), PT_REG( r27), PT_REG( r28), PT_REG( gp), -1, -1, FP_REG(fp[ 0]), FP_REG(fp[ 1]), FP_REG(fp[ 2]), FP_REG(fp[ 3]), FP_REG(fp[ 4]), FP_REG(fp[ 5]), FP_REG(fp[ 6]), FP_REG(fp[ 7]), FP_REG(fp[ 8]), FP_REG(fp[ 9]), FP_REG(fp[10]), FP_REG(fp[11]), FP_REG(fp[12]), FP_REG(fp[13]), FP_REG(fp[14]), FP_REG(fp[15]), FP_REG(fp[16]), FP_REG(fp[17]), FP_REG(fp[18]), FP_REG(fp[19]), FP_REG(fp[20]), FP_REG(fp[21]), FP_REG(fp[22]), FP_REG(fp[23]), FP_REG(fp[24]), FP_REG(fp[25]), FP_REG(fp[26]), FP_REG(fp[27]), FP_REG(fp[28]), FP_REG(fp[29]), FP_REG(fp[30]), FP_REG(fp[31]), PT_REG( pc) }; static unsigned long zero; /* * Get address of register REGNO in task TASK. */ static unsigned long * get_reg_addr(struct task_struct * task, unsigned long regno) { unsigned long *addr; if (regno == 30) { addr = &task_thread_info(task)->pcb.usp; } else if (regno == 65) { addr = &task_thread_info(task)->pcb.unique; } else if (regno == 31 || regno > 65) { zero = 0; addr = &zero; } else { addr = task_stack_page(task) + regoff[regno]; } return addr; } /* * Get contents of register REGNO in task TASK. */ static unsigned long get_reg(struct task_struct * task, unsigned long regno) { /* Special hack for fpcr -- combine hardware and software bits. */ if (regno == 63) { unsigned long fpcr = *get_reg_addr(task, regno); unsigned long swcr = task_thread_info(task)->ieee_state & IEEE_SW_MASK; swcr = swcr_update_status(swcr, fpcr); return fpcr | swcr; } return *get_reg_addr(task, regno); } static void alpha_elf_fpregs_get(struct task_struct *target, elf_fpreg_t *fpregs) /* points to ELF_NFPREG entries */ { memcpy(fpregs, task_thread_info(target)->fp, sizeof(elf_fpregset_t)); } static void alpha_elf_fpregs_set(struct task_struct *target, const elf_fpreg_t *fpregs, size_t nwords) { size_t n = min_t(size_t, nwords, ELF_NFPREG); memcpy(task_thread_info(target)->fp, fpregs, n * sizeof(elf_fpreg_t)); } static void alpha_elf_gregs_set(struct task_struct *child, const elf_greg_t *src, size_t nwords) { struct pt_regs *pt = task_pt_regs(child); struct thread_info *ti = task_thread_info(child); struct switch_stack *sw = ((struct switch_stack *)pt) - 1; /* GPRs r0..r8 live in pt_regs */ if (nwords > 0) pt->r0 = src[0]; if (nwords > 1) pt->r1 = src[1]; if (nwords > 2) pt->r2 = src[2]; if (nwords > 3) pt->r3 = src[3]; if (nwords > 4) pt->r4 = src[4]; if (nwords > 5) pt->r5 = src[5]; if (nwords > 6) pt->r6 = src[6]; if (nwords > 7) pt->r7 = src[7]; if (nwords > 8) pt->r8 = src[8]; /* r9..r15 live in switch_stack */ if (nwords > 9) sw->r9 = src[9]; if (nwords > 10) sw->r10 = src[10]; if (nwords > 11) sw->r11 = src[11]; if (nwords > 12) sw->r12 = src[12]; if (nwords > 13) sw->r13 = src[13]; if (nwords > 14) sw->r14 = src[14]; if (nwords > 15) sw->r15 = src[15]; /* r16..r28 live in pt_regs */ if (nwords > 16) pt->r16 = src[16]; if (nwords > 17) pt->r17 = src[17]; if (nwords > 18) pt->r18 = src[18]; if (nwords > 19) pt->r19 = src[19]; if (nwords > 20) pt->r20 = src[20]; if (nwords > 21) pt->r21 = src[21]; if (nwords > 22) pt->r22 = src[22]; if (nwords > 23) pt->r23 = src[23]; if (nwords > 24) pt->r24 = src[24]; if (nwords > 25) pt->r25 = src[25]; if (nwords > 26) pt->r26 = src[26]; if (nwords > 27) pt->r27 = src[27]; if (nwords > 28) pt->r28 = src[28]; /* gp, usp, pc, unique */ if (nwords > 29) pt->gp = src[29]; if (nwords > 30) { ti->pcb.usp = src[30]; /* * If someone ever does this to current (rare), keep the * hardware usp consistent. */ if (child == current) wrusp(src[30]); } if (nwords > 31) pt->pc = src[31]; if (nwords > 32) ti->pcb.unique = src[32]; /* * PTRACE_SETREGSET can be used at a syscall-entry stop to skip the * syscall by setting the syscall number to -1. The seccomp/ptrace * selftests use this to synthesize errno returns. * * Alpha uses r19/a3 as the error flag, so a skipped syscall with a * small positive r0 and a clear r19 must be normalized to an error * return. */ if (pt->r1 == (unsigned long)-1 && pt->r19 == 0 && pt->r0 > 0 && pt->r0 < MAX_ERRNO) pt->r19 = 1; } /* * Write contents of register REGNO in task TASK. */ static int put_reg(struct task_struct *task, unsigned long regno, unsigned long data) { struct pt_regs *regs = task_pt_regs(task); if (regno == 63) { task_thread_info(task)->ieee_state = ((task_thread_info(task)->ieee_state & ~IEEE_SW_MASK) | (data & IEEE_SW_MASK)); data = (data & FPCR_DYN_MASK) | ieee_swcr_to_fpcr(data); } *get_reg_addr(task, regno) = data; /* * Alpha historically exposes r0/v0 as the syscall number at a * syscall-entry stop. The generic-entry conversion keeps the * mutable syscall number in regs->r1, so old ptrace users such * as strace that skip a syscall by poking r0 to -1 must also * update the internal shadow syscall number. * * Do not mirror other r0 writes. strace later pokes r0 to the * injected return value, e.g. 42, while r1 must remain -1. */ if (regno == 0 && data == (unsigned long)-1) { regs->r1 = data; regs->r19 = 0; } return 0; } static inline int read_int(struct task_struct *task, unsigned long addr, int * data) { int copied = access_process_vm(task, addr, data, sizeof(int), FOLL_FORCE); return (copied == sizeof(int)) ? 0 : -EIO; } static inline int write_int(struct task_struct *task, unsigned long addr, int data) { int copied = access_process_vm(task, addr, &data, sizeof(int), FOLL_FORCE | FOLL_WRITE); return (copied == sizeof(int)) ? 0 : -EIO; } /* * Set breakpoint. */ int ptrace_set_bpt(struct task_struct * child) { int displ, i, res, reg_b, nsaved = 0; unsigned int insn, op_code; unsigned long pc; pc = get_reg(child, REG_PC); res = read_int(child, pc, (int *) &insn); if (res < 0) return res; op_code = insn >> 26; if (op_code >= 0x30) { /* * It's a branch: instead of trying to figure out * whether the branch will be taken or not, we'll put * a breakpoint at either location. This is simpler, * more reliable, and probably not a whole lot slower * than the alternative approach of emulating the * branch (emulation can be tricky for fp branches). */ displ = ((s32)(insn << 11)) >> 9; task_thread_info(child)->bpt_addr[nsaved++] = pc + 4; if (displ) /* guard against unoptimized code */ task_thread_info(child)->bpt_addr[nsaved++] = pc + 4 + displ; DBG(DBG_BPT, ("execing branch\n")); } else if (op_code == 0x1a) { reg_b = (insn >> 16) & 0x1f; task_thread_info(child)->bpt_addr[nsaved++] = get_reg(child, reg_b); DBG(DBG_BPT, ("execing jump\n")); } else { task_thread_info(child)->bpt_addr[nsaved++] = pc + 4; DBG(DBG_BPT, ("execing normal insn\n")); } /* install breakpoints: */ for (i = 0; i < nsaved; ++i) { res = read_int(child, task_thread_info(child)->bpt_addr[i], (int *) &insn); if (res < 0) return res; task_thread_info(child)->bpt_insn[i] = insn; DBG(DBG_BPT, (" -> next_pc=%lx\n", task_thread_info(child)->bpt_addr[i])); res = write_int(child, task_thread_info(child)->bpt_addr[i], BREAKINST); if (res < 0) return res; } task_thread_info(child)->bpt_nsaved = nsaved; return 0; } /* * Ensure no single-step breakpoint is pending. Returns non-zero * value if child was being single-stepped. */ int ptrace_cancel_bpt(struct task_struct * child) { int i, nsaved = task_thread_info(child)->bpt_nsaved; task_thread_info(child)->bpt_nsaved = 0; if (nsaved > 2) { printk("ptrace_cancel_bpt: bogus nsaved: %d!\n", nsaved); nsaved = 2; } for (i = 0; i < nsaved; ++i) { write_int(child, task_thread_info(child)->bpt_addr[i], task_thread_info(child)->bpt_insn[i]); } return (nsaved != 0); } void user_enable_single_step(struct task_struct *child) { /* Mark single stepping. */ task_thread_info(child)->bpt_nsaved = -1; } void user_disable_single_step(struct task_struct *child) { ptrace_cancel_bpt(child); } /* * Called by kernel/ptrace.c when detaching.. * * Make sure the single step bit is not set. */ void ptrace_disable(struct task_struct *child) { user_disable_single_step(child); } long arch_ptrace(struct task_struct *child, long request, unsigned long addr, unsigned long data) { unsigned long tmp; size_t copied; long ret; switch (request) { /* When I and D space are separate, these will need to be fixed. */ case PTRACE_PEEKTEXT: /* read word at location addr. */ case PTRACE_PEEKDATA: copied = ptrace_access_vm(child, addr, &tmp, sizeof(tmp), FOLL_FORCE); ret = -EIO; if (copied != sizeof(tmp)) break; force_successful_syscall_return(); ret = tmp; break; /* Read register number ADDR. */ case PTRACE_PEEKUSR: force_successful_syscall_return(); ret = get_reg(child, addr); DBG(DBG_MEM, ("peek $%lu->%#lx\n", addr, ret)); break; /* When I and D space are separate, this will have to be fixed. */ case PTRACE_POKETEXT: /* write the word at location addr. */ case PTRACE_POKEDATA: ret = generic_ptrace_pokedata(child, addr, data); break; case PTRACE_POKEUSR: /* write the specified register */ DBG(DBG_MEM, ("poke $%lu<-%#lx\n", addr, data)); ret = put_reg(child, addr, data); break; default: ret = ptrace_request(child, request, addr, data); break; } return ret; } asmlinkage unsigned long syscall_trace_enter(void) { struct pt_regs *regs = current_pt_regs(); if (test_thread_flag(TIF_SYSCALL_TRACE) && !ptrace_report_syscall_permit_entry(regs)) { syscall_set_nr(current, regs, -1); if (regs->r19 == 0 && regs->r0 == (unsigned long)-1) syscall_set_return_value(current, regs, -ENOSYS, 0); return -1UL; } /* * Do the secure computing after ptrace; failures should be fast. * If this fails, seccomp may already have set up the return value * (e.g. SECCOMP_RET_ERRNO / TRACE). */ if (!seccomp_permit_syscall()) { if (regs->r19 == 0 && regs->r0 == (unsigned long)-1) syscall_set_return_value(current, regs, -ENOSYS, 0); syscall_set_nr(current, regs, -1); return -1UL; } #ifdef CONFIG_AUDITSYSCALL audit_syscall_entry(syscall_get_nr(current, regs), regs->r16, regs->r17, regs->r18, regs->r19);