summaryrefslogtreecommitdiff
path: root/arch/x86/include/asm/text-patching.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/include/asm/text-patching.h')
-rw-r--r--arch/x86/include/asm/text-patching.h40
1 files changed, 40 insertions, 0 deletions
diff --git a/arch/x86/include/asm/text-patching.h b/arch/x86/include/asm/text-patching.h
new file mode 100644
index 000000000..903950633
--- /dev/null
+++ b/arch/x86/include/asm/text-patching.h
@@ -0,0 +1,40 @@
+#ifndef _ASM_X86_TEXT_PATCHING_H
+#define _ASM_X86_TEXT_PATCHING_H
+
+#include <linux/types.h>
+#include <linux/stddef.h>
+#include <asm/ptrace.h>
+
+struct paravirt_patch_site;
+#ifdef CONFIG_PARAVIRT
+void apply_paravirt(struct paravirt_patch_site *start,
+ struct paravirt_patch_site *end);
+#else
+static inline void apply_paravirt(struct paravirt_patch_site *start,
+ struct paravirt_patch_site *end)
+{}
+#define __parainstructions NULL
+#define __parainstructions_end NULL
+#endif
+
+extern void *text_poke_early(void *addr, const void *opcode, size_t len);
+
+/*
+ * Clear and restore the kernel write-protection flag on the local CPU.
+ * Allows the kernel to edit read-only pages.
+ * Side-effect: any interrupt handler running between save and restore will have
+ * the ability to write to read-only pages.
+ *
+ * Warning:
+ * Code patching in the UP case is safe if NMIs and MCE handlers are stopped and
+ * no thread can be preempted in the instructions being modified (no iret to an
+ * invalid instruction possible) or if the instructions are changed from a
+ * consistent state to another consistent state atomically.
+ * On the local CPU you need to be protected again NMI or MCE handlers seeing an
+ * inconsistent instruction while you patch.
+ */
+extern void *text_poke(void *addr, const void *opcode, size_t len);
+extern int poke_int3_handler(struct pt_regs *regs);
+extern void *text_poke_bp(void *addr, const void *opcode, size_t len, void *handler);
+
+#endif /* _ASM_X86_TEXT_PATCHING_H */