[PATCH v13 12/20] uprobes, arm64: untag user pointers in find_active_uprobe
From: Andrey Konovalov <hidden>
Date: 2019-03-20 14:52:29
Also in:
bpf, linux-arch, linux-kselftest, linux-media, linux-mm, lkml
Subsystem:
performance events subsystem, the rest, uprobes · Maintainers:
Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds, Masami Hiramatsu, Oleg Nesterov
This patch is a part of a series that extends arm64 kernel ABI to allow to pass tagged user pointers (with the top byte set to something else other than 0x00) as syscall arguments. find_active_uprobe() uses user pointers (obtained via instruction_pointer(regs)) for vma lookups, which can only by done with untagged pointers. Untag user pointers in this function. Signed-off-by: Andrey Konovalov <redacted> --- kernel/events/uprobes.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index c5cde87329c7..d3a2716a813a 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c@@ -1992,6 +1992,8 @@ static struct uprobe *find_active_uprobe(unsigned long bp_vaddr, int *is_swbp) struct uprobe *uprobe = NULL; struct vm_area_struct *vma; + bp_vaddr = untagged_addr(bp_vaddr); + down_read(&mm->mmap_sem); vma = find_vma(mm, bp_vaddr); if (vma && vma->vm_start <= bp_vaddr) {
--
2.21.0.225.g810b269d1ac-goog