mm/memory: Use exception ip to search exception tables

Origin: https://git.kernel.org/linus/8fa5070833886268e4fb646daaca99f725b378e9
Bug-Debian: https://bugs.debian.org/1093200
Bug-Debian: https://bugs.debian.org/1087809
Bug-Debian: https://bugs.debian.org/1086028

On architectures with delay slot, instruction_pointer() may differ
from where exception was triggered.

Use exception_ip we just introduced to search exception tables to
get rid of the problem.

Fixes: 4bce37a68ff8 ("mips/mm: Convert to using lock_mm_and_find_vma()")
Reported-by: Xi Ruoyao <xry111@xry111.site>
Link: https://lore.kernel.org/r/75e9fd7b08562ad9b456a5bdaacb7cc220311cc9.camel@xry111.site/
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Gbp-Pq: Topic bugfix/all
Gbp-Pq: Name mm-memory-Use-exception-ip-to-search-exception-table.patch

diff --git a/mm/memory.c b/mm/memory.c
index e74234449f477eadcf62f1f13d0566cb2bd2f57f..f79fe69ead4d6262df13025cd5a9b77228e5a148 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -5324,7 +5324,7 @@ static inline bool get_mmap_lock_carefully(struct mm_struct *mm, struct pt_regs
        }
 
        if (regs && !user_mode(regs)) {
-               unsigned long ip = instruction_pointer(regs);
+               unsigned long ip = exception_ip(regs);
                if (!search_exception_tables(ip))
                        return false;
        }
@@ -5349,7 +5349,7 @@ static inline bool upgrade_mmap_lock_carefully(struct mm_struct *mm, struct pt_r
 {
        mmap_read_unlock(mm);
        if (regs && !user_mode(regs)) {
-               unsigned long ip = instruction_pointer(regs);
+               unsigned long ip = exception_ip(regs);
                if (!search_exception_tables(ip))
                        return false;
        }