From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- arch/parisc/kernel/ptrace.c | 790 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 790 insertions(+) create mode 100644 arch/parisc/kernel/ptrace.c (limited to 'arch/parisc/kernel/ptrace.c') diff --git a/arch/parisc/kernel/ptrace.c b/arch/parisc/kernel/ptrace.c new file mode 100644 index 000000000..9af11abee --- /dev/null +++ b/arch/parisc/kernel/ptrace.c @@ -0,0 +1,790 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Kernel support for the ptrace() and syscall tracing interfaces. + * + * Copyright (C) 2000 Hewlett-Packard Co, Linuxcare Inc. + * Copyright (C) 2000 Matthew Wilcox + * Copyright (C) 2000 David Huggins-Daines + * Copyright (C) 2008-2016 Helge Deller + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +/* PSW bits we allow the debugger to modify */ +#define USER_PSW_BITS (PSW_N | PSW_B | PSW_V | PSW_CB) + +#define CREATE_TRACE_POINTS +#include + +/* + * These are our native regset flavors. + */ +enum parisc_regset { + REGSET_GENERAL, + REGSET_FP +}; + +/* + * Called by kernel/ptrace.c when detaching.. + * + * Make sure single step bits etc are not set. + */ +void ptrace_disable(struct task_struct *task) +{ + clear_tsk_thread_flag(task, TIF_SINGLESTEP); + clear_tsk_thread_flag(task, TIF_BLOCKSTEP); + + /* make sure the trap bits are not set */ + pa_psw(task)->r = 0; + pa_psw(task)->t = 0; + pa_psw(task)->h = 0; + pa_psw(task)->l = 0; +} + +/* + * The following functions are called by ptrace_resume() when + * enabling or disabling single/block tracing. + */ +void user_disable_single_step(struct task_struct *task) +{ + ptrace_disable(task); +} + +void user_enable_single_step(struct task_struct *task) +{ + clear_tsk_thread_flag(task, TIF_BLOCKSTEP); + set_tsk_thread_flag(task, TIF_SINGLESTEP); + + if (pa_psw(task)->n) { + /* Nullified, just crank over the queue. */ + task_regs(task)->iaoq[0] = task_regs(task)->iaoq[1]; + task_regs(task)->iasq[0] = task_regs(task)->iasq[1]; + task_regs(task)->iaoq[1] = task_regs(task)->iaoq[0] + 4; + pa_psw(task)->n = 0; + pa_psw(task)->x = 0; + pa_psw(task)->y = 0; + pa_psw(task)->z = 0; + pa_psw(task)->b = 0; + ptrace_disable(task); + /* Don't wake up the task, but let the + parent know something happened. */ + force_sig_fault_to_task(SIGTRAP, TRAP_TRACE, + (void __user *) (task_regs(task)->iaoq[0] & ~3), + task); + /* notify_parent(task, SIGCHLD); */ + return; + } + + /* Enable recovery counter traps. The recovery counter + * itself will be set to zero on a task switch. If the + * task is suspended on a syscall then the syscall return + * path will overwrite the recovery counter with a suitable + * value such that it traps once back in user space. We + * disable interrupts in the tasks PSW here also, to avoid + * interrupts while the recovery counter is decrementing. + */ + pa_psw(task)->r = 1; + pa_psw(task)->t = 0; + pa_psw(task)->h = 0; + pa_psw(task)->l = 0; +} + +void user_enable_block_step(struct task_struct *task) +{ + clear_tsk_thread_flag(task, TIF_SINGLESTEP); + set_tsk_thread_flag(task, TIF_BLOCKSTEP); + + /* Enable taken branch trap. */ + pa_psw(task)->r = 0; + pa_psw(task)->t = 1; + pa_psw(task)->h = 0; + pa_psw(task)->l = 0; +} + +long arch_ptrace(struct task_struct *child, long request, + unsigned long addr, unsigned long data) +{ + unsigned long __user *datap = (unsigned long __user *)data; + unsigned long tmp; + long ret = -EIO; + + unsigned long user_regs_struct_size = sizeof(struct user_regs_struct); +#ifdef CONFIG_64BIT + if (is_compat_task()) + user_regs_struct_size /= 2; +#endif + + switch (request) { + + /* Read the word at location addr in the USER area. For ptraced + processes, the kernel saves all regs on a syscall. */ + case PTRACE_PEEKUSR: + if ((addr & (sizeof(unsigned long)-1)) || + addr >= sizeof(struct pt_regs)) + break; + tmp = *(unsigned long *) ((char *) task_regs(child) + addr); + ret = put_user(tmp, datap); + break; + + /* Write the word at location addr in the USER area. This will need + to change when the kernel no longer saves all regs on a syscall. + FIXME. There is a problem at the moment in that r3-r18 are only + saved if the process is ptraced on syscall entry, and even then + those values are overwritten by actual register values on syscall + exit. */ + case PTRACE_POKEUSR: + /* Some register values written here may be ignored in + * entry.S:syscall_restore_rfi; e.g. iaoq is written with + * r31/r31+4, and not with the values in pt_regs. + */ + if (addr == PT_PSW) { + /* Allow writing to Nullify, Divide-step-correction, + * and carry/borrow bits. + * BEWARE, if you set N, and then single step, it won't + * stop on the nullified instruction. + */ + data &= USER_PSW_BITS; + task_regs(child)->gr[0] &= ~USER_PSW_BITS; + task_regs(child)->gr[0] |= data; + ret = 0; + break; + } + + if ((addr & (sizeof(unsigned long)-1)) || + addr >= sizeof(struct pt_regs)) + break; + if (addr == PT_IAOQ0 || addr == PT_IAOQ1) { + data |= PRIV_USER; /* ensure userspace privilege */ + } + if ((addr >= PT_GR1 && addr <= PT_GR31) || + addr == PT_IAOQ0 || addr == PT_IAOQ1 || + (addr >= PT_FR0 && addr <= PT_FR31 + 4) || + addr == PT_SAR) { + *(unsigned long *) ((char *) task_regs(child) + addr) = data; + ret = 0; + } + break; + + case PTRACE_GETREGS: /* Get all gp regs from the child. */ + return copy_regset_to_user(child, + task_user_regset_view(current), + REGSET_GENERAL, + 0, user_regs_struct_size, + datap); + + case PTRACE_SETREGS: /* Set all gp regs in the child. */ + return copy_regset_from_user(child, + task_user_regset_view(current), + REGSET_GENERAL, + 0, user_regs_struct_size, + datap); + + case PTRACE_GETFPREGS: /* Get the child FPU state. */ + return copy_regset_to_user(child, + task_user_regset_view(current), + REGSET_FP, + 0, sizeof(struct user_fp_struct), + datap); + + case PTRACE_SETFPREGS: /* Set the child FPU state. */ + return copy_regset_from_user(child, + task_user_regset_view(current), + REGSET_FP, + 0, sizeof(struct user_fp_struct), + datap); + + default: + ret = ptrace_request(child, request, addr, data); + break; + } + + return ret; +} + + +#ifdef CONFIG_COMPAT + +/* This function is needed to translate 32 bit pt_regs offsets in to + * 64 bit pt_regs offsets. For example, a 32 bit gdb under a 64 bit kernel + * will request offset 12 if it wants gr3, but the lower 32 bits of + * the 64 bit kernels view of gr3 will be at offset 28 (3*8 + 4). + * This code relies on a 32 bit pt_regs being comprised of 32 bit values + * except for the fp registers which (a) are 64 bits, and (b) follow + * the gr registers at the start of pt_regs. The 32 bit pt_regs should + * be half the size of the 64 bit pt_regs, plus 32*4 to allow for fr[] + * being 64 bit in both cases. + */ + +static compat_ulong_t translate_usr_offset(compat_ulong_t offset) +{ + compat_ulong_t pos; + + if (offset < 32*4) /* gr[0..31] */ + pos = offset * 2 + 4; + else if (offset < 32*4+32*8) /* fr[0] ... fr[31] */ + pos = (offset - 32*4) + PT_FR0; + else if (offset < sizeof(struct pt_regs)/2 + 32*4) /* sr[0] ... ipsw */ + pos = (offset - 32*4 - 32*8) * 2 + PT_SR0 + 4; + else + pos = sizeof(struct pt_regs); + + return pos; +} + +long compat_arch_ptrace(struct task_struct *child, compat_long_t request, + compat_ulong_t addr, compat_ulong_t data) +{ + compat_uint_t tmp; + long ret = -EIO; + + switch (request) { + + case PTRACE_PEEKUSR: + if (addr & (sizeof(compat_uint_t)-1)) + break; + addr = translate_usr_offset(addr); + if (addr >= sizeof(struct pt_regs)) + break; + + tmp = *(compat_uint_t *) ((char *) task_regs(child) + addr); + ret = put_user(tmp, (compat_uint_t *) (unsigned long) data); + break; + + /* Write the word at location addr in the USER area. This will need + to change when the kernel no longer saves all regs on a syscall. + FIXME. There is a problem at the moment in that r3-r18 are only + saved if the process is ptraced on syscall entry, and even then + those values are overwritten by actual register values on syscall + exit. */ + case PTRACE_POKEUSR: + /* Some register values written here may be ignored in + * entry.S:syscall_restore_rfi; e.g. iaoq is written with + * r31/r31+4, and not with the values in pt_regs. + */ + if (addr == PT_PSW) { + /* Since PT_PSW==0, it is valid for 32 bit processes + * under 64 bit kernels as well. + */ + ret = arch_ptrace(child, request, addr, data); + } else { + if (addr & (sizeof(compat_uint_t)-1)) + break; + addr = translate_usr_offset(addr); + if (addr >= sizeof(struct pt_regs)) + break; + if (addr == PT_IAOQ0+4 || addr == PT_IAOQ1+4) { + data |= PRIV_USER; /* ensure userspace privilege */ + } + if (addr >= PT_FR0 && addr <= PT_FR31 + 4) { + /* Special case, fp regs are 64 bits anyway */ + *(__u32 *) ((char *) task_regs(child) + addr) = data; + ret = 0; + } + else if ((addr >= PT_GR1+4 && addr <= PT_GR31+4) || + addr == PT_IAOQ0+4 || addr == PT_IAOQ1+4 || + addr == PT_SAR+4) { + /* Zero the top 32 bits */ + *(__u32 *) ((char *) task_regs(child) + addr - 4) = 0; + *(__u32 *) ((char *) task_regs(child) + addr) = data; + ret = 0; + } + } + break; + case PTRACE_GETREGS: + case PTRACE_SETREGS: + case PTRACE_GETFPREGS: + case PTRACE_SETFPREGS: + return arch_ptrace(child, request, addr, data); + + default: + ret = compat_ptrace_request(child, request, addr, data); + break; + } + + return ret; +} +#endif + +long do_syscall_trace_enter(struct pt_regs *regs) +{ + if (test_thread_flag(TIF_SYSCALL_TRACE)) { + int rc = ptrace_report_syscall_entry(regs); + + /* + * As tracesys_next does not set %r28 to -ENOSYS + * when %r20 is set to -1, initialize it here. + */ + regs->gr[28] = -ENOSYS; + + if (rc) { + /* + * A nonzero return code from + * ptrace_report_syscall_entry() tells us + * to prevent the syscall execution. Skip + * the syscall call and the syscall restart handling. + * + * Note that the tracer may also just change + * regs->gr[20] to an invalid syscall number, + * that is handled by tracesys_next. + */ + regs->gr[20] = -1UL; + return -1; + } + } + + /* Do the secure computing check after ptrace. */ + if (secure_computing() == -1) + return -1; + +#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS + if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) + trace_sys_enter(regs, regs->gr[20]); +#endif + +#ifdef CONFIG_64BIT + if (!is_compat_task()) + audit_syscall_entry(regs->gr[20], regs->gr[26], regs->gr[25], + regs->gr[24], regs->gr[23]); + else +#endif + audit_syscall_entry(regs->gr[20] & 0xffffffff, + regs->gr[26] & 0xffffffff, + regs->gr[25] & 0xffffffff, + regs->gr[24] & 0xffffffff, + regs->gr[23] & 0xffffffff); + + /* + * Sign extend the syscall number to 64bit since it may have been + * modified by a compat ptrace call + */ + return (int) ((u32) regs->gr[20]); +} + +void do_syscall_trace_exit(struct pt_regs *regs) +{ + int stepping = test_thread_flag(TIF_SINGLESTEP) || + test_thread_flag(TIF_BLOCKSTEP); + + audit_syscall_exit(regs); + +#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS + if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) + trace_sys_exit(regs, regs->gr[20]); +#endif + + if (stepping || test_thread_flag(TIF_SYSCALL_TRACE)) + ptrace_report_syscall_exit(regs, stepping); +} + + +/* + * regset functions. + */ + +static int fpr_get(struct task_struct *target, + const struct user_regset *regset, + struct membuf to) +{ + struct pt_regs *regs = task_regs(target); + + return membuf_write(&to, regs->fr, ELF_NFPREG * sizeof(__u64)); +} + +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) +{ + struct pt_regs *regs = task_regs(target); + const __u64 *k = kbuf; + const __u64 __user *u = ubuf; + __u64 reg; + + pos /= sizeof(reg); + count /= sizeof(reg); + + if (kbuf) + for (; count > 0 && pos < ELF_NFPREG; --count) + regs->fr[pos++] = *k++; + else + for (; count > 0 && pos < ELF_NFPREG; --count) { + if (__get_user(reg, u++)) + return -EFAULT; + regs->fr[pos++] = reg; + } + + kbuf = k; + ubuf = u; + pos *= sizeof(reg); + count *= sizeof(reg); + return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, + ELF_NFPREG * sizeof(reg), -1); +} + +#define RI(reg) (offsetof(struct user_regs_struct,reg) / sizeof(long)) + +static unsigned long get_reg(struct pt_regs *regs, int num) +{ + switch (num) { + case RI(gr[0]) ... RI(gr[31]): return regs->gr[num - RI(gr[0])]; + case RI(sr[0]) ... RI(sr[7]): return regs->sr[num - RI(sr[0])]; + case RI(iasq[0]): return regs->iasq[0]; + case RI(iasq[1]): return regs->iasq[1]; + case RI(iaoq[0]): return regs->iaoq[0]; + case RI(iaoq[1]): return regs->iaoq[1]; + case RI(sar): return regs->sar; + case RI(iir): return regs->iir; + case RI(isr): return regs->isr; + case RI(ior): return regs->ior; + case RI(ipsw): return regs->ipsw; + case RI(cr27): return regs->cr27; + case RI(cr0): return mfctl(0); + case RI(cr24): return mfctl(24); + case RI(cr25): return mfctl(25); + case RI(cr26): return mfctl(26); + case RI(cr28): return mfctl(28); + case RI(cr29): return mfctl(29); + case RI(cr30): return mfctl(30); + case RI(cr31): return mfctl(31); + case RI(cr8): return mfctl(8); + case RI(cr9): return mfctl(9); + case RI(cr12): return mfctl(12); + case RI(cr13): return mfctl(13); + case RI(cr10): return mfctl(10); + case RI(cr15): return mfctl(15); + default: return 0; + } +} + +static void set_reg(struct pt_regs *regs, int num, unsigned long val) +{ + switch (num) { + case RI(gr[0]): /* + * PSW is in gr[0]. + * Allow writing to Nullify, Divide-step-correction, + * and carry/borrow bits. + * BEWARE, if you set N, and then single step, it won't + * stop on the nullified instruction. + */ + val &= USER_PSW_BITS; + regs->gr[0] &= ~USER_PSW_BITS; + regs->gr[0] |= val; + return; + case RI(gr[1]) ... RI(gr[31]): + regs->gr[num - RI(gr[0])] = val; + return; + case RI(iaoq[0]): + case RI(iaoq[1]): + /* set 2 lowest bits to ensure userspace privilege: */ + regs->iaoq[num - RI(iaoq[0])] = val | PRIV_USER; + return; + case RI(sar): regs->sar = val; + return; + default: return; +#if 0 + /* do not allow to change any of the following registers (yet) */ + case RI(sr[0]) ... RI(sr[7]): return regs->sr[num - RI(sr[0])]; + case RI(iasq[0]): return regs->iasq[0]; + case RI(iasq[1]): return regs->iasq[1]; + case RI(iir): return regs->iir; + case RI(isr): return regs->isr; + case RI(ior): return regs->ior; + case RI(ipsw): return regs->ipsw; + case RI(cr27): return regs->cr27; + case cr0, cr24, cr25, cr26, cr27, cr28, cr29, cr30, cr31; + case cr8, cr9, cr12, cr13, cr10, cr15; +#endif + } +} + +static int gpr_get(struct task_struct *target, + const struct user_regset *regset, + struct membuf to) +{ + struct pt_regs *regs = task_regs(target); + unsigned int pos; + + for (pos = 0; pos < ELF_NGREG; pos++) + membuf_store(&to, get_reg(regs, pos)); + return 0; +} + +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) +{ + struct pt_regs *regs = task_regs(target); + const unsigned long *k = kbuf; + const unsigned long __user *u = ubuf; + unsigned long reg; + + pos /= sizeof(reg); + count /= sizeof(reg); + + if (kbuf) + for (; count > 0 && pos < ELF_NGREG; --count) + set_reg(regs, pos++, *k++); + else + for (; count > 0 && pos < ELF_NGREG; --count) { + if (__get_user(reg, u++)) + return -EFAULT; + set_reg(regs, pos++, reg); + } + + kbuf = k; + ubuf = u; + pos *= sizeof(reg); + count *= sizeof(reg); + return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, + ELF_NGREG * sizeof(reg), -1); +} + +static const struct user_regset native_regsets[] = { + [REGSET_GENERAL] = { + .core_note_type = NT_PRSTATUS, .n = ELF_NGREG, + .size = sizeof(long), .align = sizeof(long), + .regset_get = gpr_get, .set = gpr_set + }, + [REGSET_FP] = { + .core_note_type = NT_PRFPREG, .n = ELF_NFPREG, + .size = sizeof(__u64), .align = sizeof(__u64), + .regset_get = fpr_get, .set = fpr_set + } +}; + +static const struct user_regset_view user_parisc_native_view = { + .name = "parisc", .e_machine = ELF_ARCH, .ei_osabi = ELFOSABI_LINUX, + .regsets = native_regsets, .n = ARRAY_SIZE(native_regsets) +}; + +#ifdef CONFIG_64BIT +static int gpr32_get(struct task_struct *target, + const struct user_regset *regset, + struct membuf to) +{ + struct pt_regs *regs = task_regs(target); + unsigned int pos; + + for (pos = 0; pos < ELF_NGREG; pos++) + membuf_store(&to, (compat_ulong_t)get_reg(regs, pos)); + + return 0; +} + +static int gpr32_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_regs(target); + const compat_ulong_t *k = kbuf; + const compat_ulong_t __user *u = ubuf; + compat_ulong_t reg; + + pos /= sizeof(reg); + count /= sizeof(reg); + + if (kbuf) + for (; count > 0 && pos < ELF_NGREG; --count) + set_reg(regs, pos++, *k++); + else + for (; count > 0 && pos < ELF_NGREG; --count) { + if (__get_user(reg, u++)) + return -EFAULT; + set_reg(regs, pos++, reg); + } + + kbuf = k; + ubuf = u; + pos *= sizeof(reg); + count *= sizeof(reg); + return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, + ELF_NGREG * sizeof(reg), -1); +} + +/* + * These are the regset flavors matching the 32bit native set. + */ +static const struct user_regset compat_regsets[] = { + [REGSET_GENERAL] = { + .core_note_type = NT_PRSTATUS, .n = ELF_NGREG, + .size = sizeof(compat_long_t), .align = sizeof(compat_long_t), + .regset_get = gpr32_get, .set = gpr32_set + }, + [REGSET_FP] = { + .core_note_type = NT_PRFPREG, .n = ELF_NFPREG, + .size = sizeof(__u64), .align = sizeof(__u64), + .regset_get = fpr_get, .set = fpr_set + } +}; + +static const struct user_regset_view user_parisc_compat_view = { + .name = "parisc", .e_machine = EM_PARISC, .ei_osabi = ELFOSABI_LINUX, + .regsets = compat_regsets, .n = ARRAY_SIZE(compat_regsets) +}; +#endif /* CONFIG_64BIT */ + +const struct user_regset_view *task_user_regset_view(struct task_struct *task) +{ + BUILD_BUG_ON(sizeof(struct user_regs_struct)/sizeof(long) != ELF_NGREG); + BUILD_BUG_ON(sizeof(struct user_fp_struct)/sizeof(__u64) != ELF_NFPREG); +#ifdef CONFIG_64BIT + if (is_compat_task()) + return &user_parisc_compat_view; +#endif + return &user_parisc_native_view; +} + + +/* HAVE_REGS_AND_STACK_ACCESS_API feature */ + +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_INDEX(r,i) {.name = #r#i, .offset = offsetof(struct pt_regs, r[i])} +#define REG_OFFSET_END {.name = NULL, .offset = 0} + +static const struct pt_regs_offset regoffset_table[] = { + REG_OFFSET_INDEX(gr,0), + REG_OFFSET_INDEX(gr,1), + REG_OFFSET_INDEX(gr,2), + REG_OFFSET_INDEX(gr,3), + REG_OFFSET_INDEX(gr,4), + REG_OFFSET_INDEX(gr,5), + REG_OFFSET_INDEX(gr,6), + REG_OFFSET_INDEX(gr,7), + REG_OFFSET_INDEX(gr,8), + REG_OFFSET_INDEX(gr,9), + REG_OFFSET_INDEX(gr,10), + REG_OFFSET_INDEX(gr,11), + REG_OFFSET_INDEX(gr,12), + REG_OFFSET_INDEX(gr,13), + REG_OFFSET_INDEX(gr,14), + REG_OFFSET_INDEX(gr,15), + REG_OFFSET_INDEX(gr,16), + REG_OFFSET_INDEX(gr,17), + REG_OFFSET_INDEX(gr,18), + REG_OFFSET_INDEX(gr,19), + REG_OFFSET_INDEX(gr,20), + REG_OFFSET_INDEX(gr,21), + REG_OFFSET_INDEX(gr,22), + REG_OFFSET_INDEX(gr,23), + REG_OFFSET_INDEX(gr,24), + REG_OFFSET_INDEX(gr,25), + REG_OFFSET_INDEX(gr,26), + REG_OFFSET_INDEX(gr,27), + REG_OFFSET_INDEX(gr,28), + REG_OFFSET_INDEX(gr,29), + REG_OFFSET_INDEX(gr,30), + REG_OFFSET_INDEX(gr,31), + REG_OFFSET_INDEX(sr,0), + REG_OFFSET_INDEX(sr,1), + REG_OFFSET_INDEX(sr,2), + REG_OFFSET_INDEX(sr,3), + REG_OFFSET_INDEX(sr,4), + REG_OFFSET_INDEX(sr,5), + REG_OFFSET_INDEX(sr,6), + REG_OFFSET_INDEX(sr,7), + REG_OFFSET_INDEX(iasq,0), + REG_OFFSET_INDEX(iasq,1), + REG_OFFSET_INDEX(iaoq,0), + REG_OFFSET_INDEX(iaoq,1), + REG_OFFSET_NAME(cr27), + REG_OFFSET_NAME(ksp), + REG_OFFSET_NAME(kpc), + REG_OFFSET_NAME(sar), + REG_OFFSET_NAME(iir), + REG_OFFSET_NAME(isr), + REG_OFFSET_NAME(ior), + REG_OFFSET_NAME(ipsw), + 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_query_register_name() - query register name from its offset + * @offset: the offset of a register in struct pt_regs. + * + * regs_query_register_name() returns the name of a register from its + * offset in struct pt_regs. If the @offset is invalid, this returns NULL; + */ +const char *regs_query_register_name(unsigned int offset) +{ + const struct pt_regs_offset *roff; + for (roff = regoffset_table; roff->name != NULL; roff++) + if (roff->offset == offset) + return roff->name; + return NULL; +} + +/** + * 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. + */ +int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr) +{ + return ((addr & ~(THREAD_SIZE - 1)) == + (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))); +} + +/** + * 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 0; + + return *addr; +} -- cgit v1.2.3