obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
obj-$(CONFIG_STACKTRACE) += stacktrace.o
obj-$(CONFIG_KPROBES) += kprobes.o
+obj-$(CONFIG_KPROBES) += kprobes_insn_page.o
obj-$(CONFIG_FUNCTION_TRACER) += mcount.o ftrace.o
obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
obj-$(CONFIG_UPROBES) += uprobes.o
unsigned long stack_alloc(void);
void stack_free(unsigned long stack);
+extern char kprobes_insn_page[];
+
#endif /* _ENTRY_H */
#include <asm/set_memory.h>
#include <asm/sections.h>
#include <asm/dis.h>
+#include "entry.h"
DEFINE_PER_CPU(struct kprobe *, current_kprobe);
DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
DEFINE_INSN_CACHE_OPS(s390_insn);
static int insn_page_in_use;
-static char insn_page[PAGE_SIZE] __aligned(PAGE_SIZE);
void *alloc_insn_page(void)
{
{
if (xchg(&insn_page_in_use, 1) == 1)
return NULL;
- __set_memory((unsigned long) &insn_page, 1, SET_MEMORY_RO | SET_MEMORY_X);
- return &insn_page;
+ return &kprobes_insn_page;
}
static void free_s390_insn_page(void *page)
{
- __set_memory((unsigned long) page, 1, SET_MEMORY_RW | SET_MEMORY_NX);
xchg(&insn_page_in_use, 0);
}
--- /dev/null
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <linux/linkage.h>
+
+/*
+ * insn_page is a special 4k aligned dummy function for kprobes.
+ * It will contain all kprobed instructions that are out-of-line executed.
+ * The page must be within the kernel image to guarantee that the
+ * out-of-line instructions are within 2GB distance of their original
+ * location. Using a dummy function ensures that the insn_page is within
+ * the text section of the kernel and mapped read-only/executable from
+ * the beginning on, thus avoiding to split large mappings if the page
+ * would be in the data section instead.
+ */
+ .section .kprobes.text, "ax"
+ .align 4096
+ENTRY(kprobes_insn_page)
+ .rept 2048
+ .word 0x07fe
+ .endr
+ENDPROC(kprobes_insn_page)
+ .previous