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authorKirill A. Shutemov <kirill.shutemov@linux.intel.com>2023-08-09 17:46:00 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2023-08-09 08:05:23 -0700
commit22883973244b1caaa26f9c6171a41ba843c8d4bd (patch)
tree125495296da587957fde03d6f3a6dabdc85258d0 /mm
parent77245f1c3c6495521f6a3af082696ee2f8ce3921 (diff)
mm: Fix access_remote_vm() regression on tagged addresses
GDB uses /proc/PID/mem to access memory of the target process. GDB doesn't untag addresses manually, but relies on kernel to do the right thing. mem_rw() of procfs uses access_remote_vm() to get data from the target process. It worked fine until recent changes in __access_remote_vm() that now checks if there's VMA at target address using raw address. Untag the address before looking up the VMA. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Christina Schimpe <christina.schimpe@intel.com> Fixes: eee9c708cc89 ("gup: avoid stack expansion warning for known-good case") Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/memory.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/mm/memory.c b/mm/memory.c
index 603b2f419948..1ec1ef3418bf 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -5705,6 +5705,9 @@ int __access_remote_vm(struct mm_struct *mm, unsigned long addr, void *buf,
if (mmap_read_lock_killable(mm))
return 0;
+ /* Untag the address before looking up the VMA */
+ addr = untagged_addr_remote(mm, addr);
+
/* Avoid triggering the temporary warning in __get_user_pages */
if (!vma_lookup(mm, addr) && !expand_stack(mm, addr))
return 0;