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| author | Horacio Mijail Anton Quiles <hmijail@gmail.com> | 2015-07-17 16:24:04 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-07-17 16:39:53 -0700 |
| commit | 0f70fe605fad0f3215818ba79fc12617c0ec7f90 (patch) | |
| tree | 4e0e1768928926e774f92081fa5236df02df8fe2 | |
| parent | b4749e96a4a872c2496602566f205547c4e3c950 (diff) | |
| download | lwn-0f70fe605fad0f3215818ba79fc12617c0ec7f90.tar.gz lwn-0f70fe605fad0f3215818ba79fc12617c0ec7f90.zip | |
hexdump: fix for non-aligned buffers
A hexdump with a buf not aligned to the groupsize causes
non-naturally-aligned memory accesses. This was causing a kernel panic
on the processor BlackFin BF527, when such an unaligned buffer was fed
by the function ubifs_scanned_corruption in fs/ubifs/scan.c .
To fix this, change accesses to the contents of the buffer so they go
through get_unaligned(). This change should be harmless to unaligned-
access-capable architectures, and any performance hit should be anyway
dwarfed by the snprintf() processing time.
Signed-off-by: Horacio Mijail Antón Quiles <hmijail@gmail.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Joe Perches <joe@perches.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | lib/hexdump.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/lib/hexdump.c b/lib/hexdump.c index 7ea09699855d..8d74c20d8595 100644 --- a/lib/hexdump.c +++ b/lib/hexdump.c @@ -11,6 +11,7 @@ #include <linux/ctype.h> #include <linux/kernel.h> #include <linux/export.h> +#include <asm/unaligned.h> const char hex_asc[] = "0123456789abcdef"; EXPORT_SYMBOL(hex_asc); @@ -139,7 +140,7 @@ int hex_dump_to_buffer(const void *buf, size_t len, int rowsize, int groupsize, for (j = 0; j < ngroups; j++) { ret = snprintf(linebuf + lx, linebuflen - lx, "%s%16.16llx", j ? " " : "", - (unsigned long long)*(ptr8 + j)); + get_unaligned(ptr8 + j)); if (ret >= linebuflen - lx) goto overflow1; lx += ret; @@ -150,7 +151,7 @@ int hex_dump_to_buffer(const void *buf, size_t len, int rowsize, int groupsize, for (j = 0; j < ngroups; j++) { ret = snprintf(linebuf + lx, linebuflen - lx, "%s%8.8x", j ? " " : "", - *(ptr4 + j)); + get_unaligned(ptr4 + j)); if (ret >= linebuflen - lx) goto overflow1; lx += ret; @@ -161,7 +162,7 @@ int hex_dump_to_buffer(const void *buf, size_t len, int rowsize, int groupsize, for (j = 0; j < ngroups; j++) { ret = snprintf(linebuf + lx, linebuflen - lx, "%s%4.4x", j ? " " : "", - *(ptr2 + j)); + get_unaligned(ptr2 + j)); if (ret >= linebuflen - lx) goto overflow1; lx += ret; |