[PATCH v12 11/13] uprobes, arm64: untag user pointers in find_active_uprobe
From: Andrey Konovalov <hidden>
Date: 2019-03-18 17:18:27
Also in:
bpf, linux-arch, linux-arm-kernel, linux-doc, linux-kselftest, 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 provided user pointer (obtained via
instruction_pointer(regs)) for vma lookups, which can only by done with
untagged pointers.
Untag the user pointer 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