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Diffstat (limited to 'arch/arm/kernel/patch.c')
-rw-r--r--arch/arm/kernel/patch.c92
1 files changed, 73 insertions, 19 deletions
diff --git a/arch/arm/kernel/patch.c b/arch/arm/kernel/patch.c
index 07314af47733..5038960e3c55 100644
--- a/arch/arm/kernel/patch.c
+++ b/arch/arm/kernel/patch.c
@@ -1,8 +1,11 @@
#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>
@@ -13,21 +16,77 @@ struct patch {
unsigned int insn;
};
-void __kprobes __patch_text(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 *)addr = __opcode_to_mem_thumb16(insn);
+ *(u16 *)waddr = __opcode_to_mem_thumb16(insn);
size = sizeof(u16);
- } else if (thumb2 && ((uintptr_t)addr & 2)) {
+ } else if (thumb2 && (uintaddr & 2)) {
u16 first = __opcode_thumb32_first(insn);
u16 second = __opcode_thumb32_second(insn);
- u16 *addrh = addr;
+ 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);
- addrh[0] = __opcode_to_mem_thumb16(first);
- addrh[1] = __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 {
@@ -36,10 +95,16 @@ void __kprobes __patch_text(void *addr, unsigned int insn)
else
insn = __opcode_to_mem_arm(insn);
- *(u32 *)addr = 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);
}
@@ -60,16 +125,5 @@ void __kprobes patch_text(void *addr, unsigned int insn)
.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);
- }
+ stop_machine(patch_text_stop_machine, &patch, NULL);
}