linux/arch/arm/kernel/patch.c
Wang Nan fca08f326a ARM: probes: move all probe code to dedicate directory
In discussion on LKML (https://lkml.org/lkml/2014/11/28/158), Russell
King suggests to move all probe related code to arch/arm/probes. This
patch does the work. Due to dependency on 'arch/arm/kernel/patch.h', this
patch also moves patch.h to 'arch/arm/include/asm/patch.h', and related
'#include' directives are also midified to '#include <asm/patch.h>'.

Following is an overview of this patch:

 ./arch/arm/kernel/               ./arch/arm/probes/
 |-- Makefile                     |-- Makefile
 |-- probes-arm.c          ==>    |-- decode-arm.c
 |-- probes-arm.h          ==>    |-- decode-arm.h
 |-- probes-thumb.c        ==>    |-- decode-thumb.c
 |-- probes-thumb.h        ==>    |-- decode-thumb.h
 |-- probes.c              ==>    |-- decode.c
 |-- probes.h              ==>    |-- decode.h
 |                                |-- kprobes
 |                                |   |-- Makefile
 |-- kprobes-arm.c         ==>    |   |-- actions-arm.c
 |-- kprobes-common.c      ==>    |   |-- actions-common.c
 |-- kprobes-thumb.c       ==>    |   |-- actions-thumb.c
 |-- kprobes.c             ==>    |   |-- core.c
 |-- kprobes.h             ==>    |   |-- core.h
 |-- kprobes-test-arm.c    ==>    |   |-- test-arm.c
 |-- kprobes-test.c        ==>    |   |-- test-core.c
 |-- kprobes-test.h        ==>    |   |-- test-core.h
 |-- kprobes-test-thumb.c  ==>    |   `-- test-thumb.c
 |                                `-- uprobes
 |                                    |-- Makefile
 |-- uprobes-arm.c         ==>        |-- actions-arm.c
 |-- uprobes.c             ==>        |-- core.c
 |-- uprobes.h             ==>        `-- core.h
 |
 `-- patch.h               ==>    arch/arm/include/asm/patch.h

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Jon Medhurst <tixy@linaro.org>
2015-01-09 09:36:50 +00:00

129 lines
2.8 KiB
C

#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/kprobes.h>
#include <linux/mm.h>
#include <linux/stop_machine.h>
#include <asm/cacheflush.h>
#include <asm/fixmap.h>
#include <asm/smp_plat.h>
#include <asm/opcodes.h>
#include <asm/patch.h>
struct patch {
void *addr;
unsigned int insn;
};
static DEFINE_SPINLOCK(patch_lock);
static void __kprobes *patch_map(void *addr, int fixmap, unsigned long *flags)
__acquires(&patch_lock)
{
unsigned int uintaddr = (uintptr_t) addr;
bool module = !core_kernel_text(uintaddr);
struct page *page;
if (module && IS_ENABLED(CONFIG_DEBUG_SET_MODULE_RONX))
page = vmalloc_to_page(addr);
else if (!module && IS_ENABLED(CONFIG_DEBUG_RODATA))
page = virt_to_page(addr);
else
return addr;
if (flags)
spin_lock_irqsave(&patch_lock, *flags);
else
__acquire(&patch_lock);
set_fixmap(fixmap, page_to_phys(page));
return (void *) (__fix_to_virt(fixmap) + (uintaddr & ~PAGE_MASK));
}
static void __kprobes patch_unmap(int fixmap, unsigned long *flags)
__releases(&patch_lock)
{
clear_fixmap(fixmap);
if (flags)
spin_unlock_irqrestore(&patch_lock, *flags);
else
__release(&patch_lock);
}
void __kprobes __patch_text_real(void *addr, unsigned int insn, bool remap)
{
bool thumb2 = IS_ENABLED(CONFIG_THUMB2_KERNEL);
unsigned int uintaddr = (uintptr_t) addr;
bool twopage = false;
unsigned long flags;
void *waddr = addr;
int size;
if (remap)
waddr = patch_map(addr, FIX_TEXT_POKE0, &flags);
else
__acquire(&patch_lock);
if (thumb2 && __opcode_is_thumb16(insn)) {
*(u16 *)waddr = __opcode_to_mem_thumb16(insn);
size = sizeof(u16);
} else if (thumb2 && (uintaddr & 2)) {
u16 first = __opcode_thumb32_first(insn);
u16 second = __opcode_thumb32_second(insn);
u16 *addrh0 = waddr;
u16 *addrh1 = waddr + 2;
twopage = (uintaddr & ~PAGE_MASK) == PAGE_SIZE - 2;
if (twopage && remap)
addrh1 = patch_map(addr + 2, FIX_TEXT_POKE1, NULL);
*addrh0 = __opcode_to_mem_thumb16(first);
*addrh1 = __opcode_to_mem_thumb16(second);
if (twopage && addrh1 != addr + 2) {
flush_kernel_vmap_range(addrh1, 2);
patch_unmap(FIX_TEXT_POKE1, NULL);
}
size = sizeof(u32);
} else {
if (thumb2)
insn = __opcode_to_mem_thumb32(insn);
else
insn = __opcode_to_mem_arm(insn);
*(u32 *)waddr = insn;
size = sizeof(u32);
}
if (waddr != addr) {
flush_kernel_vmap_range(waddr, twopage ? size / 2 : size);
patch_unmap(FIX_TEXT_POKE0, &flags);
} else
__release(&patch_lock);
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,
};
stop_machine(patch_text_stop_machine, &patch, NULL);
}