b21d55e98a
Extract out the code patching code from kprobes so that it can be used from the jump label code. Additionally, the separated code: - Uses the IS_ENABLED() macros instead of the #ifdefs for THUMB2 support - Unifies the two separate functions in kprobes, providing one function that uses stop_machine() internally, and one that can be called from stop_machine() directly - Patches the text on all CPUs only on processors requiring software broadcasting of cache operations Acked-by: Jon Medhurst <tixy@yxit.co.uk> Tested-by: Jon Medhurst <tixy@yxit.co.uk> Signed-off-by: Rabin Vincent <rabin@rab.in> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
75 lines
1.6 KiB
C
75 lines
1.6 KiB
C
#include <linux/kernel.h>
|
|
#include <linux/kprobes.h>
|
|
#include <linux/stop_machine.h>
|
|
|
|
#include <asm/cacheflush.h>
|
|
#include <asm/smp_plat.h>
|
|
#include <asm/opcodes.h>
|
|
|
|
#include "patch.h"
|
|
|
|
struct patch {
|
|
void *addr;
|
|
unsigned int insn;
|
|
};
|
|
|
|
void __kprobes __patch_text(void *addr, unsigned int insn)
|
|
{
|
|
bool thumb2 = IS_ENABLED(CONFIG_THUMB2_KERNEL);
|
|
int size;
|
|
|
|
if (thumb2 && __opcode_is_thumb16(insn)) {
|
|
*(u16 *)addr = __opcode_to_mem_thumb16(insn);
|
|
size = sizeof(u16);
|
|
} else if (thumb2 && ((uintptr_t)addr & 2)) {
|
|
u16 first = __opcode_thumb32_first(insn);
|
|
u16 second = __opcode_thumb32_second(insn);
|
|
u16 *addrh = addr;
|
|
|
|
addrh[0] = __opcode_to_mem_thumb16(first);
|
|
addrh[1] = __opcode_to_mem_thumb16(second);
|
|
|
|
size = sizeof(u32);
|
|
} else {
|
|
if (thumb2)
|
|
insn = __opcode_to_mem_thumb32(insn);
|
|
else
|
|
insn = __opcode_to_mem_arm(insn);
|
|
|
|
*(u32 *)addr = insn;
|
|
size = sizeof(u32);
|
|
}
|
|
|
|
flush_icache_range((uintptr_t)(addr),
|
|
(uintptr_t)(addr) + size);
|
|
}
|
|
|
|
static int __kprobes patch_text_stop_machine(void *data)
|
|
{
|
|
struct patch *patch = data;
|
|
|
|
__patch_text(patch->addr, patch->insn);
|
|
|
|
return 0;
|
|
}
|
|
|
|
void __kprobes patch_text(void *addr, unsigned int insn)
|
|
{
|
|
struct patch patch = {
|
|
.addr = addr,
|
|
.insn = insn,
|
|
};
|
|
|
|
if (cache_ops_need_broadcast()) {
|
|
stop_machine(patch_text_stop_machine, &patch, cpu_online_mask);
|
|
} else {
|
|
bool straddles_word = IS_ENABLED(CONFIG_THUMB2_KERNEL)
|
|
&& __opcode_is_thumb32(insn)
|
|
&& ((uintptr_t)addr & 2);
|
|
|
|
if (straddles_word)
|
|
stop_machine(patch_text_stop_machine, &patch, NULL);
|
|
else
|
|
__patch_text(addr, insn);
|
|
}
|
|
}
|