cregit-Linux how code gets into the kernel

Release 4.14 arch/sh/kernel/ptrace_64.c

Directory: arch/sh/kernel
/*
 * arch/sh/kernel/ptrace_64.c
 *
 * Copyright (C) 2000, 2001  Paolo Alberelli
 * Copyright (C) 2003 - 2008  Paul Mundt
 *
 * Started from SH3/4 version:
 *   SuperH version:   Copyright (C) 1999, 2000  Kaz Kojima & Niibe Yutaka
 *
 *   Original x86 implementation:
 *      By Ross Biro 1/23/92
 *      edited by Linus Torvalds
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#include <linux/kernel.h>
#include <linux/rwsem.h>
#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/bitops.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/signal.h>
#include <linux/syscalls.h>
#include <linux/audit.h>
#include <linux/seccomp.h>
#include <linux/tracehook.h>
#include <linux/elf.h>
#include <linux/regset.h>
#include <asm/io.h>
#include <linux/uaccess.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/mmu_context.h>
#include <asm/syscalls.h>
#include <asm/fpu.h>
#include <asm/traps.h>


#define CREATE_TRACE_POINTS
#include <trace/events/syscalls.h>

/* This mask defines the bits of the SR which the user is not allowed to
   change, which are everything except S, Q, M, PR, SZ, FR. */

#define SR_MASK      (0xffff8cfd)

/*
 * does not yet catch signals sent when the child dies.
 * in exit.c or in signal.c.
 */

/*
 * This routine will get a word from the user area in the process kernel stack.
 */

static inline int get_stack_long(struct task_struct *task, int offset) { unsigned char *stack; stack = (unsigned char *)(task->thread.uregs); stack += offset; return (*((int *)stack)); }

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Paul Mundt51100.00%1100.00%
Total51100.00%1100.00%


static inline unsigned long get_fpu_long(struct task_struct *task, unsigned long addr) { unsigned long tmp; struct pt_regs *regs; regs = (struct pt_regs*)((unsigned char *)task + THREAD_SIZE) - 1; if (!tsk_used_math(task)) { if (addr == offsetof(struct user_fpu_struct, fpscr)) { tmp = FPSCR_INIT; } else { tmp = 0xffffffffUL; /* matches initial value in fpu.c */ } return tmp; } if (last_task_used_math == task) { enable_fpu(); save_fpu(task); disable_fpu(); last_task_used_math = 0; regs->sr |= SR_FD; } tmp = ((long *)task->thread.xstate)[addr / sizeof(unsigned long)]; return tmp; }

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Paul Mundt13797.86%480.00%
Andrea Arcangeli32.14%120.00%
Total140100.00%5100.00%

/* * This routine will put a word into the user area in the process kernel stack. */
static inline int put_stack_long(struct task_struct *task, int offset, unsigned long data) { unsigned char *stack; stack = (unsigned char *)(task->thread.uregs); stack += offset; *(unsigned long *) stack = data; return 0; }

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Paul Mundt56100.00%1100.00%
Total56100.00%1100.00%


static inline int put_fpu_long(struct task_struct *task, unsigned long addr, unsigned long data) { struct pt_regs *regs; regs = (struct pt_regs*)((unsigned char *)task + THREAD_SIZE) - 1; if (!tsk_used_math(task)) { init_fpu(task); } else if (last_task_used_math == task) { enable_fpu(); save_fpu(task); disable_fpu(); last_task_used_math = 0; regs->sr |= SR_FD; } ((long *)task->thread.xstate)[addr / sizeof(unsigned long)] = data; return 0; }

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Paul Mundt11195.69%583.33%
Andrea Arcangeli54.31%116.67%
Total116100.00%6100.00%


void user_enable_single_step(struct task_struct *child) { struct pt_regs *regs = child->thread.uregs; regs->sr |= SR_SSTEP; /* auto-resetting upon exception */ set_tsk_thread_flag(child, TIF_SINGLESTEP); }

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Paul Mundt35100.00%2100.00%
Total35100.00%2100.00%


void user_disable_single_step(struct task_struct *child) { struct pt_regs *regs = child->thread.uregs; regs->sr &= ~SR_SSTEP; clear_tsk_thread_flag(child, TIF_SINGLESTEP); }

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Paul Mundt2468.57%266.67%
Adrian Bunk1131.43%133.33%
Total35100.00%3100.00%


static int genregs_get(struct task_struct *target, const struct user_regset *regset, unsigned int pos, unsigned int count, void *kbuf, void __user *ubuf) { const struct pt_regs *regs = task_pt_regs(target); int ret; /* PC, SR, SYSCALL */ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &regs->pc, 0, 3 * sizeof(unsigned long long)); /* R1 -> R63 */ if (!ret) ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs->regs, offsetof(struct pt_regs, regs[0]), 63 * sizeof(unsigned long long)); /* TR0 -> TR7 */ if (!ret) ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs->tregs, offsetof(struct pt_regs, tregs[0]), 8 * sizeof(unsigned long long)); if (!ret) ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, sizeof(struct pt_regs), -1); return ret; }

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Paul Mundt20698.10%250.00%
Christoph Hellwig31.43%125.00%
Andrea Arcangeli10.48%125.00%
Total210100.00%4100.00%


static int genregs_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 *regs = task_pt_regs(target); int ret; /* PC, SR, SYSCALL */ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &regs->pc, 0, 3 * sizeof(unsigned long long)); /* R1 -> R63 */ if (!ret && count > 0) ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs->regs, offsetof(struct pt_regs, regs[0]), 63 * sizeof(unsigned long long)); /* TR0 -> TR7 */ if (!ret && count > 0) ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs->tregs, offsetof(struct pt_regs, tregs[0]), 8 * sizeof(unsigned long long)); if (!ret) ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, sizeof(struct pt_regs), -1); return ret; }

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Paul Mundt219100.00%1100.00%
Total219100.00%1100.00%

#ifdef CONFIG_SH_FPU
int fpregs_get(struct task_struct *target, const struct user_regset *regset, unsigned int pos, unsigned int count, void *kbuf, void __user *ubuf) { int ret; ret = init_fpu(target); if (ret) return ret; return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &target->thread.xstate->hardfpu, 0, -1); }

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Paul Mundt80100.00%2100.00%
Total80100.00%2100.00%


static int fpregs_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; ret = init_fpu(target); if (ret) return ret; set_stopped_child_used_math(target); return user_regset_copyin(&pos, &count, &kbuf, &ubuf, &target->thread.xstate->hardfpu, 0, -1); }

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Paul Mundt88100.00%2100.00%
Total88100.00%2100.00%


static int fpregs_active(struct task_struct *target, const struct user_regset *regset) { return tsk_used_math(target) ? regset->n : 0; }

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Paul Mundt29100.00%1100.00%
Total29100.00%1100.00%

#endif const struct pt_regs_offset regoffset_table[] = { REG_OFFSET_NAME(pc), REG_OFFSET_NAME(sr), REG_OFFSET_NAME(syscall_nr), REGS_OFFSET_NAME(0), REGS_OFFSET_NAME(1), REGS_OFFSET_NAME(2), REGS_OFFSET_NAME(3), REGS_OFFSET_NAME(4), REGS_OFFSET_NAME(5), REGS_OFFSET_NAME(6), REGS_OFFSET_NAME(7), REGS_OFFSET_NAME(8), REGS_OFFSET_NAME(9), REGS_OFFSET_NAME(10), REGS_OFFSET_NAME(11), REGS_OFFSET_NAME(12), REGS_OFFSET_NAME(13), REGS_OFFSET_NAME(14), REGS_OFFSET_NAME(15), REGS_OFFSET_NAME(16), REGS_OFFSET_NAME(17), REGS_OFFSET_NAME(18), REGS_OFFSET_NAME(19), REGS_OFFSET_NAME(20), REGS_OFFSET_NAME(21), REGS_OFFSET_NAME(22), REGS_OFFSET_NAME(23), REGS_OFFSET_NAME(24), REGS_OFFSET_NAME(25), REGS_OFFSET_NAME(26), REGS_OFFSET_NAME(27), REGS_OFFSET_NAME(28), REGS_OFFSET_NAME(29), REGS_OFFSET_NAME(30), REGS_OFFSET_NAME(31), REGS_OFFSET_NAME(32), REGS_OFFSET_NAME(33), REGS_OFFSET_NAME(34), REGS_OFFSET_NAME(35), REGS_OFFSET_NAME(36), REGS_OFFSET_NAME(37), REGS_OFFSET_NAME(38), REGS_OFFSET_NAME(39), REGS_OFFSET_NAME(40), REGS_OFFSET_NAME(41), REGS_OFFSET_NAME(42), REGS_OFFSET_NAME(43), REGS_OFFSET_NAME(44), REGS_OFFSET_NAME(45), REGS_OFFSET_NAME(46), REGS_OFFSET_NAME(47), REGS_OFFSET_NAME(48), REGS_OFFSET_NAME(49), REGS_OFFSET_NAME(50), REGS_OFFSET_NAME(51), REGS_OFFSET_NAME(52), REGS_OFFSET_NAME(53), REGS_OFFSET_NAME(54), REGS_OFFSET_NAME(55), REGS_OFFSET_NAME(56), REGS_OFFSET_NAME(57), REGS_OFFSET_NAME(58), REGS_OFFSET_NAME(59), REGS_OFFSET_NAME(60), REGS_OFFSET_NAME(61), REGS_OFFSET_NAME(62), REGS_OFFSET_NAME(63), TREGS_OFFSET_NAME(0), TREGS_OFFSET_NAME(1), TREGS_OFFSET_NAME(2), TREGS_OFFSET_NAME(3), TREGS_OFFSET_NAME(4), TREGS_OFFSET_NAME(5), TREGS_OFFSET_NAME(6), TREGS_OFFSET_NAME(7), REG_OFFSET_END, }; /* * These are our native regset flavours. */ enum sh_regset { REGSET_GENERAL, #ifdef CONFIG_SH_FPU REGSET_FPU, #endif }; static const struct user_regset sh_regsets[] = { /* * Format is: * PC, SR, SYSCALL, * R1 --> R63, * TR0 --> TR7, */ [REGSET_GENERAL] = { .core_note_type = NT_PRSTATUS, .n = ELF_NGREG, .size = sizeof(long long), .align = sizeof(long long), .get = genregs_get, .set = genregs_set, }, #ifdef CONFIG_SH_FPU [REGSET_FPU] = { .core_note_type = NT_PRFPREG, .n = sizeof(struct user_fpu_struct) / sizeof(long long), .size = sizeof(long long), .align = sizeof(long long), .get = fpregs_get, .set = fpregs_set, .active = fpregs_active, }, #endif }; static const struct user_regset_view user_sh64_native_view = { .name = "sh64", .e_machine = EM_SH, .regsets = sh_regsets, .n = ARRAY_SIZE(sh_regsets), };
const struct user_regset_view *task_user_regset_view(struct task_struct *task) { return &user_sh64_native_view; }

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Paul Mundt17100.00%1100.00%
Total17100.00%1100.00%


long arch_ptrace(struct task_struct *child, long request, unsigned long addr, unsigned long data) { int ret; unsigned long __user *datap = (unsigned long __user *) data; switch (request) { /* read the word at location addr in the USER area. */ case PTRACE_PEEKUSR: { unsigned long tmp; ret = -EIO; if ((addr & 3) || addr < 0) break; if (addr < sizeof(struct pt_regs)) tmp = get_stack_long(child, addr); else if ((addr >= offsetof(struct user, fpu)) && (addr < offsetof(struct user, u_fpvalid))) { unsigned long index; ret = init_fpu(child); if (ret) break; index = addr - offsetof(struct user, fpu); tmp = get_fpu_long(child, index); } else if (addr == offsetof(struct user, u_fpvalid)) { tmp = !!tsk_used_math(child); } else { break; } ret = put_user(tmp, datap); break; } case PTRACE_POKEUSR: /* write the word at location addr in the USER area. We must disallow any changes to certain SR bits or u_fpvalid, since this could crash the kernel or result in a security loophole. */ ret = -EIO; if ((addr & 3) || addr < 0) break; if (addr < sizeof(struct pt_regs)) { /* Ignore change of top 32 bits of SR */ if (addr == offsetof (struct pt_regs, sr)+4) { ret = 0; break; } /* If lower 32 bits of SR, ignore non-user bits */ if (addr == offsetof (struct pt_regs, sr)) { long cursr = get_stack_long(child, addr); data &= ~(SR_MASK); data |= (cursr & SR_MASK); } ret = put_stack_long(child, addr, data); } else if ((addr >= offsetof(struct user, fpu)) && (addr < offsetof(struct user, u_fpvalid))) { unsigned long index; ret = init_fpu(child); if (ret) break; index = addr - offsetof(struct user, fpu); ret = put_fpu_long(child, index, data); } break; case PTRACE_GETREGS: return copy_regset_to_user(child, &user_sh64_native_view, REGSET_GENERAL, 0, sizeof(struct pt_regs), datap); case PTRACE_SETREGS: return copy_regset_from_user(child, &user_sh64_native_view, REGSET_GENERAL, 0, sizeof(struct pt_regs), datap); #ifdef CONFIG_SH_FPU case PTRACE_GETFPREGS: return copy_regset_to_user(child, &user_sh64_native_view, REGSET_FPU, 0, sizeof(struct user_fpu_struct), datap); case PTRACE_SETFPREGS: return copy_regset_from_user(child, &user_sh64_native_view, REGSET_FPU, 0, sizeof(struct user_fpu_struct), datap); #endif default: ret = ptrace_request(child, request, addr, data); break; } return ret; }

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Paul Mundt41584.69%233.33%
Namhyung Kim479.59%233.33%
Phil Edworthy244.90%116.67%
Christoph Hellwig40.82%116.67%
Total490100.00%6100.00%


asmlinkage int sh64_ptrace(long request, long pid, unsigned long addr, unsigned long data) { #define WPC_DBRMODE 0x0d104008 static unsigned long first_call; if (!test_and_set_bit(0, &first_call)) { /* Set WPC.DBRMODE to 0. This makes all debug events get * delivered through RESVEC, i.e. into the handlers in entry.S. * (If the kernel was downloaded using a remote gdb, WPC.DBRMODE * would normally be left set to 1, which makes debug events get * delivered through DBRVEC, i.e. into the remote gdb's * handlers. This prevents ptrace getting them, and confuses * the remote gdb.) */ printk("DBRMODE set to 0 to permit native debugging\n"); poke_real_address_q(WPC_DBRMODE, 0); } return sys_ptrace(request, pid, addr, data); }

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Christoph Hellwig5176.12%125.00%
Arnd Bergmann913.43%125.00%
Paul Mundt57.46%125.00%
Namhyung Kim22.99%125.00%
Total67100.00%4100.00%


asmlinkage long long do_syscall_trace_enter(struct pt_regs *regs) { long long ret = 0; secure_computing_strict(regs->regs[9]); if (test_thread_flag(TIF_SYSCALL_TRACE) && tracehook_report_syscall_entry(regs)) /* * Tracing decided this syscall should not happen. * We'll return a bogus call number to get an ENOSYS * error, but leave the original number in regs->regs[0]. */ ret = -1LL; if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) trace_sys_enter(regs, regs->regs[9]); audit_syscall_entry(regs->regs[1], regs->regs[2], regs->regs[3], regs->regs[4], regs->regs[5]); return ret ?: regs->regs[9]; }

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Paul Mundt11598.29%571.43%
Roland McGrath10.85%114.29%
Will Drewry10.85%114.29%
Total117100.00%7100.00%


asmlinkage void do_syscall_trace_leave(struct pt_regs *regs) { int step; audit_syscall_exit(regs); if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) trace_sys_exit(regs, regs->regs[9]); step = test_thread_flag(TIF_SINGLESTEP); if (step || test_thread_flag(TIF_SYSCALL_TRACE)) tracehook_report_syscall_exit(regs, step); }

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Paul Mundt64100.00%4100.00%
Total64100.00%4100.00%

/* Called with interrupts disabled */
asmlinkage void do_single_step(unsigned long long vec, struct pt_regs *regs) { /* This is called after a single step exception (DEBUGSS). There is no need to change the PC, as it is a post-execution exception, as entry.S does not do anything to the PC for DEBUGSS. We need to clear the Single Step setting in SR to avoid continually stepping. */ local_irq_enable(); regs->sr &= ~SR_SSTEP; force_sig(SIGTRAP, current); }

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Paul Mundt34100.00%1100.00%
Total34100.00%1100.00%

/* Called with interrupts disabled */ BUILD_TRAP_HANDLER(breakpoint) { TRAP_HANDLER_DECL; /* We need to forward step the PC, to counteract the backstep done in signal.c. */ local_irq_enable(); force_sig(SIGTRAP, current); regs->pc += 4; } /* * Called by kernel/ptrace.c when detaching.. * * Make sure single step bits etc are not set. */
void ptrace_disable(struct task_struct *child) { user_disable_single_step(child); }

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Paul Mundt15100.00%2100.00%
Total15100.00%2100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Paul Mundt235692.90%1551.72%
Christoph Hellwig612.41%13.45%
Namhyung Kim491.93%26.90%
Phil Edworthy240.95%13.45%
Adrian Bunk130.51%26.90%
Arnd Bergmann100.39%13.45%
Andrea Arcangeli90.35%13.45%
David Howells50.20%13.45%
Ingo Molnar30.12%13.45%
Jesper Juhl30.12%13.45%
Will Drewry10.04%13.45%
Linus Torvalds10.04%13.45%
Roland McGrath10.04%13.45%
Total2536100.00%29100.00%
Directory: arch/sh/kernel
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