linux_dsm_epyc7002/arch/csky/kernel/ptrace.c
Guo Ren bfe47f358a csky: Implement ptrace regs and stack API
Needed for kprobes support. Copied and adapted from Patrick's patch,
but it has been modified for csky's pt_regs.

ref:
https://lore.kernel.org/linux-riscv/1572919114-3886-2-git-send-email-vincent.chen@sifive.com/raw

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Patrick Staehlin <me@packi.ch>
2020-03-08 20:55:14 +08:00

420 lines
11 KiB
C

// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
#include <linux/audit.h>
#include <linux/elf.h>
#include <linux/errno.h>
#include <linux/kernel.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/signal.h>
#include <linux/smp.h>
#include <linux/tracehook.h>
#include <linux/uaccess.h>
#include <linux/user.h>
#include <asm/thread_info.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/asm-offsets.h>
#include <abi/regdef.h>
#define CREATE_TRACE_POINTS
#include <trace/events/syscalls.h>
/* sets the trace bits. */
#define TRACE_MODE_SI (1 << 14)
#define TRACE_MODE_RUN 0
#define TRACE_MODE_MASK ~(0x3 << 14)
/*
* Make sure the single step bit is not set.
*/
static void singlestep_disable(struct task_struct *tsk)
{
struct pt_regs *regs;
regs = task_pt_regs(tsk);
regs->sr = (regs->sr & TRACE_MODE_MASK) | TRACE_MODE_RUN;
}
static void singlestep_enable(struct task_struct *tsk)
{
struct pt_regs *regs;
regs = task_pt_regs(tsk);
regs->sr = (regs->sr & TRACE_MODE_MASK) | TRACE_MODE_SI;
}
/*
* Make sure the single step bit is set.
*/
void user_enable_single_step(struct task_struct *child)
{
singlestep_enable(child);
}
void user_disable_single_step(struct task_struct *child)
{
singlestep_disable(child);
}
enum csky_regset {
REGSET_GPR,
REGSET_FPR,
};
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 pt_regs *regs;
regs = task_pt_regs(target);
/* Abiv1 regs->tls is fake and we need sync here. */
regs->tls = task_thread_info(target)->tp_value;
return user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs, 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 pt_regs regs;
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &regs, 0, -1);
if (ret)
return ret;
regs.sr = task_pt_regs(target)->sr;
#ifdef CONFIG_CPU_HAS_HILO
regs.dcsr = task_pt_regs(target)->dcsr;
#endif
task_thread_info(target)->tp_value = regs.tls;
*task_pt_regs(target) = regs;
return 0;
}
static int fpr_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
struct user_fp *regs = (struct user_fp *)&target->thread.user_fp;
#if defined(CONFIG_CPU_HAS_FPUV2) && !defined(CONFIG_CPU_HAS_VDSP)
int i;
struct user_fp tmp = *regs;
for (i = 0; i < 16; i++) {
tmp.vr[i*4] = regs->vr[i*2];
tmp.vr[i*4 + 1] = regs->vr[i*2 + 1];
}
for (i = 0; i < 32; i++)
tmp.vr[64 + i] = regs->vr[32 + i];
return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &tmp, 0, -1);
#else
return user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
#endif
}
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;
struct user_fp *regs = (struct user_fp *)&target->thread.user_fp;
#if defined(CONFIG_CPU_HAS_FPUV2) && !defined(CONFIG_CPU_HAS_VDSP)
int i;
struct user_fp tmp;
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tmp, 0, -1);
*regs = tmp;
for (i = 0; i < 16; i++) {
regs->vr[i*2] = tmp.vr[i*4];
regs->vr[i*2 + 1] = tmp.vr[i*4 + 1];
}
for (i = 0; i < 32; i++)
regs->vr[32 + i] = tmp.vr[64 + i];
#else
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
#endif
return ret;
}
static const struct user_regset csky_regsets[] = {
[REGSET_GPR] = {
.core_note_type = NT_PRSTATUS,
.n = sizeof(struct pt_regs) / sizeof(u32),
.size = sizeof(u32),
.align = sizeof(u32),
.get = &gpr_get,
.set = &gpr_set,
},
[REGSET_FPR] = {
.core_note_type = NT_PRFPREG,
.n = sizeof(struct user_fp) / sizeof(u32),
.size = sizeof(u32),
.align = sizeof(u32),
.get = &fpr_get,
.set = &fpr_set,
},
};
static const struct user_regset_view user_csky_view = {
.name = "csky",
.e_machine = ELF_ARCH,
.regsets = csky_regsets,
.n = ARRAY_SIZE(csky_regsets),
};
const struct user_regset_view *task_user_regset_view(struct task_struct *task)
{
return &user_csky_view;
}
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}
static const struct pt_regs_offset regoffset_table[] = {
REG_OFFSET_NAME(tls),
REG_OFFSET_NAME(lr),
REG_OFFSET_NAME(pc),
REG_OFFSET_NAME(sr),
REG_OFFSET_NAME(usp),
REG_OFFSET_NAME(orig_a0),
REG_OFFSET_NAME(a0),
REG_OFFSET_NAME(a1),
REG_OFFSET_NAME(a2),
REG_OFFSET_NAME(a3),
REG_OFFSET_NAME(regs[0]),
REG_OFFSET_NAME(regs[1]),
REG_OFFSET_NAME(regs[2]),
REG_OFFSET_NAME(regs[3]),
REG_OFFSET_NAME(regs[4]),
REG_OFFSET_NAME(regs[5]),
REG_OFFSET_NAME(regs[6]),
REG_OFFSET_NAME(regs[7]),
REG_OFFSET_NAME(regs[8]),
REG_OFFSET_NAME(regs[9]),
#if defined(__CSKYABIV2__)
REG_OFFSET_NAME(exregs[0]),
REG_OFFSET_NAME(exregs[1]),
REG_OFFSET_NAME(exregs[2]),
REG_OFFSET_NAME(exregs[3]),
REG_OFFSET_NAME(exregs[4]),
REG_OFFSET_NAME(exregs[5]),
REG_OFFSET_NAME(exregs[6]),
REG_OFFSET_NAME(exregs[7]),
REG_OFFSET_NAME(exregs[8]),
REG_OFFSET_NAME(exregs[9]),
REG_OFFSET_NAME(exregs[10]),
REG_OFFSET_NAME(exregs[11]),
REG_OFFSET_NAME(exregs[12]),
REG_OFFSET_NAME(exregs[13]),
REG_OFFSET_NAME(exregs[14]),
REG_OFFSET_NAME(rhi),
REG_OFFSET_NAME(rlo),
REG_OFFSET_NAME(dcsr),
#endif
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));
}
/**
* 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;
}
void ptrace_disable(struct task_struct *child)
{
singlestep_disable(child);
}
long arch_ptrace(struct task_struct *child, long request,
unsigned long addr, unsigned long data)
{
long ret = -EIO;
switch (request) {
default:
ret = ptrace_request(child, request, addr, data);
break;
}
return ret;
}
asmlinkage void syscall_trace_enter(struct pt_regs *regs)
{
if (test_thread_flag(TIF_SYSCALL_TRACE))
if (tracehook_report_syscall_entry(regs))
syscall_set_nr(current, regs, -1);
if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
trace_sys_enter(regs, syscall_get_nr(current, regs));
audit_syscall_entry(regs_syscallid(regs), regs->a0, regs->a1, regs->a2, regs->a3);
}
asmlinkage void syscall_trace_exit(struct pt_regs *regs)
{
audit_syscall_exit(regs);
if (test_thread_flag(TIF_SYSCALL_TRACE))
tracehook_report_syscall_exit(regs, 0);
if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
trace_sys_exit(regs, syscall_get_return_value(current, regs));
}
extern void show_stack(struct task_struct *task, unsigned long *stack);
void show_regs(struct pt_regs *fp)
{
unsigned long *sp;
unsigned char *tp;
int i;
pr_info("\nCURRENT PROCESS:\n\n");
pr_info("COMM=%s PID=%d\n", current->comm, current->pid);
if (current->mm) {
pr_info("TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",
(int) current->mm->start_code,
(int) current->mm->end_code,
(int) current->mm->start_data,
(int) current->mm->end_data,
(int) current->mm->end_data,
(int) current->mm->brk);
pr_info("USER-STACK=%08x KERNEL-STACK=%08x\n\n",
(int) current->mm->start_stack,
(int) (((unsigned long) current) + 2 * PAGE_SIZE));
}
pr_info("PC: 0x%08lx (%pS)\n", (long)fp->pc, (void *)fp->pc);
pr_info("LR: 0x%08lx (%pS)\n", (long)fp->lr, (void *)fp->lr);
pr_info("SP: 0x%08lx\n", (long)fp);
pr_info("orig_a0: 0x%08lx\n", fp->orig_a0);
pr_info("PSR: 0x%08lx\n", (long)fp->sr);
pr_info(" a0: 0x%08lx a1: 0x%08lx a2: 0x%08lx a3: 0x%08lx\n",
fp->a0, fp->a1, fp->a2, fp->a3);
#if defined(__CSKYABIV2__)
pr_info(" r4: 0x%08lx r5: 0x%08lx r6: 0x%08lx r7: 0x%08lx\n",
fp->regs[0], fp->regs[1], fp->regs[2], fp->regs[3]);
pr_info(" r8: 0x%08lx r9: 0x%08lx r10: 0x%08lx r11: 0x%08lx\n",
fp->regs[4], fp->regs[5], fp->regs[6], fp->regs[7]);
pr_info("r12: 0x%08lx r13: 0x%08lx r15: 0x%08lx\n",
fp->regs[8], fp->regs[9], fp->lr);
pr_info("r16: 0x%08lx r17: 0x%08lx r18: 0x%08lx r19: 0x%08lx\n",
fp->exregs[0], fp->exregs[1], fp->exregs[2], fp->exregs[3]);
pr_info("r20: 0x%08lx r21: 0x%08lx r22: 0x%08lx r23: 0x%08lx\n",
fp->exregs[4], fp->exregs[5], fp->exregs[6], fp->exregs[7]);
pr_info("r24: 0x%08lx r25: 0x%08lx r26: 0x%08lx r27: 0x%08lx\n",
fp->exregs[8], fp->exregs[9], fp->exregs[10], fp->exregs[11]);
pr_info("r28: 0x%08lx r29: 0x%08lx r30: 0x%08lx tls: 0x%08lx\n",
fp->exregs[12], fp->exregs[13], fp->exregs[14], fp->tls);
pr_info(" hi: 0x%08lx lo: 0x%08lx\n",
fp->rhi, fp->rlo);
#else
pr_info(" r6: 0x%08lx r7: 0x%08lx r8: 0x%08lx r9: 0x%08lx\n",
fp->regs[0], fp->regs[1], fp->regs[2], fp->regs[3]);
pr_info("r10: 0x%08lx r11: 0x%08lx r12: 0x%08lx r13: 0x%08lx\n",
fp->regs[4], fp->regs[5], fp->regs[6], fp->regs[7]);
pr_info("r14: 0x%08lx r1: 0x%08lx r15: 0x%08lx\n",
fp->regs[8], fp->regs[9], fp->lr);
#endif
pr_info("\nCODE:");
tp = ((unsigned char *) fp->pc) - 0x20;
tp += ((int)tp % 4) ? 2 : 0;
for (sp = (unsigned long *) tp, i = 0; (i < 0x40); i += 4) {
if ((i % 0x10) == 0)
pr_cont("\n%08x: ", (int) (tp + i));
pr_cont("%08x ", (int) *sp++);
}
pr_cont("\n");
pr_info("\nKERNEL STACK:");
tp = ((unsigned char *) fp) - 0x40;
for (sp = (unsigned long *) tp, i = 0; (i < 0xc0); i += 4) {
if ((i % 0x10) == 0)
pr_cont("\n%08x: ", (int) (tp + i));
pr_cont("%08x ", (int) *sp++);
}
pr_cont("\n");
show_stack(NULL, (unsigned long *)fp->regs[4]);
return;
}