The patch titled
Linux Kernel Markers - Alignment Fix
has been removed from the -mm tree. Its filename was
linux-kernel-markers-alignment-fix.patch
This patch was dropped because it was folded into linux-kernel-markers.patch
------------------------------------------------------
Subject: Linux Kernel Markers - Alignment Fix
From: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxx>
Fix the alignment of the struct marker declaration in the trace_mark()
macro. Otherwise, we run into problems on 64 bits architectures where the
struct marker structure is bigger than 32 bytes : gcc becomes
alignment-happy and align these structures on 32 bytes while the iteration
on the markers is itself only aligned on 8 bytes, as specified by the type
attribute. Specifying the alignmentof the type only is not enough to
restrain gcc happiness; we must specify a variable alignment attribute too.
This bug causes NULL pointer dereference at module load time on x86_64 when
we load marker-example.ko.
Thanks to Mike Mason for reporting this.
It applies to 2.6.23-rc8-mm2, after the linux kernel markers coding style
fixes. This is an important bugfix that should be merged with the
markers.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Cc: Mike Mason <mmlnx@xxxxxxxxxx>
Cc: "Frank Ch. Eigler" <fche@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
diff -puN include/linux/marker.h~linux-kernel-markers-alignment-fix include/linux/marker.h
--- a/include/linux/marker.h~linux-kernel-markers-alignment-fix
+++ a/include/linux/marker.h
@@ -58,7 +58,7 @@ struct marker {
__attribute__((section("__markers_strings"))) \
= format; \
static struct marker __mark_##name \
- __attribute__((section("__markers"))) = \
+ __attribute__((section("__markers"), aligned(8))) = \
{ __mstrtab_name_##name, __mstrtab_format_##name, \
0, __mark_empty_function, NULL }; \
asm volatile("" : : "i" (&__mark_##name)); \
_
Patches currently in -mm which might be from mathieu.desnoyers@xxxxxxxxxx are
origin.patch
change-struct-marker-users.patch
combine-instrumentation-menus-in-kernel-kconfiginstrumentation.patch
linux-kernel-markers.patch
linux-kernel-markers-alignment-fix.patch
add-samples-subdir.patch
linux-kernel-markers-samples.patch
linux-kernel-markers-samples-checkpatch-fixes.patch
linux-kernel-markers-samples-coding-style-fix.patch
linux-kernel-markers-samples-remove-asm.patch
linux-kernel-markers-documentation.patch
-
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