mirror of https://gitee.com/openkylin/linux.git
121 lines
2.5 KiB
C
121 lines
2.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Copyright (C) 2020 SiFive
|
|
*/
|
|
|
|
#include <linux/spinlock.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/stop_machine.h>
|
|
#include <asm/kprobes.h>
|
|
#include <asm/cacheflush.h>
|
|
#include <asm/fixmap.h>
|
|
|
|
struct riscv_insn_patch {
|
|
void *addr;
|
|
u32 insn;
|
|
atomic_t cpu_count;
|
|
};
|
|
|
|
#ifdef CONFIG_MMU
|
|
static DEFINE_RAW_SPINLOCK(patch_lock);
|
|
|
|
static void __kprobes *patch_map(void *addr, int fixmap)
|
|
{
|
|
uintptr_t uintaddr = (uintptr_t) addr;
|
|
struct page *page;
|
|
|
|
if (core_kernel_text(uintaddr))
|
|
page = phys_to_page(__pa_symbol(addr));
|
|
else if (IS_ENABLED(CONFIG_STRICT_MODULE_RWX))
|
|
page = vmalloc_to_page(addr);
|
|
else
|
|
return addr;
|
|
|
|
BUG_ON(!page);
|
|
|
|
return (void *)set_fixmap_offset(fixmap, page_to_phys(page) +
|
|
(uintaddr & ~PAGE_MASK));
|
|
}
|
|
|
|
static void __kprobes patch_unmap(int fixmap)
|
|
{
|
|
clear_fixmap(fixmap);
|
|
}
|
|
|
|
static int __kprobes riscv_insn_write(void *addr, const void *insn, size_t len)
|
|
{
|
|
void *waddr = addr;
|
|
bool across_pages = (((uintptr_t) addr & ~PAGE_MASK) + len) > PAGE_SIZE;
|
|
unsigned long flags = 0;
|
|
int ret;
|
|
|
|
raw_spin_lock_irqsave(&patch_lock, flags);
|
|
|
|
if (across_pages)
|
|
patch_map(addr + len, FIX_TEXT_POKE1);
|
|
|
|
waddr = patch_map(addr, FIX_TEXT_POKE0);
|
|
|
|
ret = probe_kernel_write(waddr, insn, len);
|
|
|
|
patch_unmap(FIX_TEXT_POKE0);
|
|
|
|
if (across_pages)
|
|
patch_unmap(FIX_TEXT_POKE1);
|
|
|
|
raw_spin_unlock_irqrestore(&patch_lock, flags);
|
|
|
|
return ret;
|
|
}
|
|
#else
|
|
static int __kprobes riscv_insn_write(void *addr, const void *insn, size_t len)
|
|
{
|
|
return probe_kernel_write(addr, insn, len);
|
|
}
|
|
#endif /* CONFIG_MMU */
|
|
|
|
int __kprobes riscv_patch_text_nosync(void *addr, const void *insns, size_t len)
|
|
{
|
|
u32 *tp = addr;
|
|
int ret;
|
|
|
|
ret = riscv_insn_write(tp, insns, len);
|
|
|
|
if (!ret)
|
|
flush_icache_range((uintptr_t) tp, (uintptr_t) tp + len);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int __kprobes riscv_patch_text_cb(void *data)
|
|
{
|
|
struct riscv_insn_patch *patch = data;
|
|
int ret = 0;
|
|
|
|
if (atomic_inc_return(&patch->cpu_count) == 1) {
|
|
ret =
|
|
riscv_patch_text_nosync(patch->addr, &patch->insn,
|
|
GET_INSN_LENGTH(patch->insn));
|
|
atomic_inc(&patch->cpu_count);
|
|
} else {
|
|
while (atomic_read(&patch->cpu_count) <= num_online_cpus())
|
|
cpu_relax();
|
|
smp_mb();
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
int __kprobes riscv_patch_text(void *addr, u32 insn)
|
|
{
|
|
struct riscv_insn_patch patch = {
|
|
.addr = addr,
|
|
.insn = insn,
|
|
.cpu_count = ATOMIC_INIT(0),
|
|
};
|
|
|
|
return stop_machine_cpuslocked(riscv_patch_text_cb,
|
|
&patch, cpu_online_mask);
|
|
}
|