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.
seq_print_user_ip() uses provided user pointers for vma lookups, which
can only by done with untagged pointers.
Untag user pointers in this function.
Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
---
kernel/trace/trace_output.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 54373d93e251..6376bee93c84 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -370,6 +370,7 @@ static int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
{
struct file *file = NULL;
unsigned long vmstart = 0;
+ unsigned long untagged_ip = untagged_addr(ip);
int ret = 1;
if (s->full)
@@ -379,7 +380,7 @@ static int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
const struct vm_area_struct *vma;
down_read(&mm->mmap_sem);
- vma = find_vma(mm, ip);
+ vma = find_vma(mm, untagged_ip);
if (vma) {
file = vma->vm_file;
vmstart = vma->vm_start;
@@ -388,7 +389,7 @@ static int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
ret = trace_seq_path(s, &file->f_path);
if (ret)
trace_seq_printf(s, "[+0x%lx]",
- ip - vmstart);
+ untagged_ip - vmstart);
}
up_read(&mm->mmap_sem);
}
--
2.21.0.225.g810b269d1ac-goog
