The kprobe page is allocated by execmem allocator with ROX permission. It needs to call set_memory_rox() to set proper permission for the direct map too. It was missed.
Fixes: 10d5e97c1bf8 ("arm64: use PAGE_KERNEL_ROX directly in alloc_insn_page") Cc: stable@vger.kernel.org Signed-off-by: Yang Shi yang@os.amperecomputing.com Reviewed-by: Catalin Marinas catalin.marinas@arm.com --- v2: Separated the patch from BBML2 series since it is an orthogonal bug fix per Ryan. Fixed the variable name nit per Catalin. Collected R-bs from Catalin.
arch/arm64/kernel/probes/kprobes.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c index 0c5d408afd95..8ab6104a4883 100644 --- a/arch/arm64/kernel/probes/kprobes.c +++ b/arch/arm64/kernel/probes/kprobes.c @@ -10,6 +10,7 @@
#define pr_fmt(fmt) "kprobes: " fmt
+#include <linux/execmem.h> #include <linux/extable.h> #include <linux/kasan.h> #include <linux/kernel.h> @@ -41,6 +42,17 @@ DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); static void __kprobes post_kprobe_handler(struct kprobe *, struct kprobe_ctlblk *, struct pt_regs *);
+void *alloc_insn_page(void) +{ + void *addr; + + addr = execmem_alloc(EXECMEM_KPROBES, PAGE_SIZE); + if (!addr) + return NULL; + set_memory_rox((unsigned long)addr, 1); + return addr; +} + static void __kprobes arch_prepare_ss_slot(struct kprobe *p) { kprobe_opcode_t *addr = p->ainsn.xol_insn;