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// SPDX-License-Identifier: GPL-2.0-only
#include <linux/highmem.h>
#include <linux/ptrace.h>
#include <linux/uprobes.h>
#include "decode-insn.h"
#define UPROBE_TRAP_NR UINT_MAX
bool is_swbp_insn(uprobe_opcode_t *insn)
{
#ifdef CONFIG_RISCV_ISA_C
return (*insn & 0xffff) == UPROBE_SWBP_INSN;
#else
return *insn == UPROBE_SWBP_INSN;
#endif
}
unsigned long uprobe_get_swbp_addr(struct pt_regs *regs)
{
return instruction_pointer(regs);
}
int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm,
unsigned long addr)
{
probe_opcode_t opcode;
opcode = *(probe_opcode_t *)(&auprobe->insn[0]);
auprobe->insn_size = GET_INSN_LENGTH(opcode);
switch (riscv_probe_decode_insn(&opcode, &auprobe->api)) {
case INSN_REJECTED:
return -EINVAL;
case INSN_GOOD_NO_SLOT:
auprobe->simulate = true;
break;
case INSN_GOOD:
auprobe->simulate = false;
break;
default:
return -EINVAL;
}
return 0;
}
int arch_uprobe_pre_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
{
struct uprobe_task *utask = current->utask;
utask->autask.saved_cause = current->thread.bad_cause;
current->thread.bad_cause = UPROBE_TRAP_NR;
instruction_pointer_set(regs, utask->xol_vaddr);
return 0;
}
int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
{
struct uprobe_task *utask = current->utask;
WARN_ON_ONCE(current->thread.bad_cause != UPROBE_TRAP_NR);
current->thread.bad_cause = utask->autask.saved_cause;
instruction_pointer_set(regs, utask->vaddr + auprobe->insn_size);
return 0;
}
bool arch_uprobe_xol_was_trapped(struct task_struct *t)
{
if (t->thread.bad_cause != UPROBE_TRAP_NR)
return true;
return false;
}
bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs)
{
probe_opcode_t insn;
unsigned long addr;
if (!auprobe->simulate)
return false;
insn = *(probe_opcode_t *)(&auprobe->insn[0]);
addr = instruction_pointer(regs);
if (auprobe->api.handler)
auprobe->api.handler(insn, addr, regs);
return true;
}
void arch_uprobe_abort_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
{
struct uprobe_task *utask = current->utask;
current->thread.bad_cause = utask->autask.saved_cause;
/*
* Task has received a fatal signal, so reset back to probbed
* address.
*/
instruction_pointer_set(regs, utask->vaddr);
}
bool arch_uretprobe_is_alive(struct return_instance *ret, enum rp_check ctx,
struct pt_regs *regs)
{
if (ctx == RP_CHECK_CHAIN_CALL)
return regs->sp <= ret->stack;
else
return regs->sp < ret->stack;
}
unsigned long
arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr,
struct pt_regs *regs)
{
unsigned long ra;
ra = regs->ra;
regs->ra = trampoline_vaddr;
return ra;
}
int arch_uprobe_exception_notify(struct notifier_block *self,
unsigned long val, void *data)
{
return NOTIFY_DONE;
}
bool uprobe_breakpoint_handler(struct pt_regs *regs)
{
if (uprobe_pre_sstep_notifier(regs))
return true;
return false;
}
bool uprobe_single_step_handler(struct pt_regs *regs)
{
if (uprobe_post_sstep_notifier(regs))
return true;
return false;
}
void arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr,
void *src, unsigned long len)
{
/* Initialize the slot */
void *kaddr = kmap_atomic(page);
void *dst = kaddr + (vaddr & ~PAGE_MASK);
memcpy(dst, src, len);
/* Add ebreak behind opcode to simulate singlestep */
if (vaddr) {
dst += GET_INSN_LENGTH(*(probe_opcode_t *)src);
*(uprobe_opcode_t *)dst = __BUG_INSN_32;
}
kunmap_atomic(kaddr);
/*
* We probably need flush_icache_user_page() but it needs vma.
* This should work on most of architectures by default. If
* architecture needs to do something different it can define
* its own version of the function.
*/
flush_dcache_page(page);
}
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