* [PATCH 1/3] Introduce __u64_aligned and U64_ALIGN() for structure alignment in custom sections
2011-01-26 4:04 [PATCH 0/3] [GIT PULL][v2.6.38] tracing: fix unaligned event arrays Steven Rostedt
@ 2011-01-26 4:05 ` Steven Rostedt
2011-01-26 4:05 ` [PATCH 2/3] tracing: Fix sparc64 alignment crash with __u64_aligned/U64_ALIGN() Steven Rostedt
` (2 subsequent siblings)
3 siblings, 0 replies; 11+ messages in thread
From: Steven Rostedt @ 2011-01-26 4:05 UTC (permalink / raw)
To: linux-kernel
Cc: Ingo Molnar, Andrew Morton, Frederic Weisbecker, David Miller,
Mathieu Desnoyers
[-- Attachment #1: 0001-Introduce-__u64_aligned-and-U64_ALIGN-for-structure-.patch --]
[-- Type: text/plain, Size: 6008 bytes --]
From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Problem description:
gcc happily align on 32-byte structures defined statically. Ftrace trace events
and Tracepoints both statically define structures into custom sections (using
the "section" attribute), to then assign these to symbols with the linker
scripts to iterate these sections as an array.
However, gcc uses different alignments for these structures when they are
defined statically than when they are globally visible and/or in an array.
Therefore iteration on these arrays sees "holes" of padding. gcc is within its
rights to increase the alignment of the statically defined structures because,
normally, there should be no other accesses to them than in the local object. We
are actually iterating on the generated structures as if they were an array
without letting gcc know anything about it.
This patch introduces __u64_aligned to force gcc to use the u64 type and
variable alignment, up-aligning or down-aligning the target type if necessary.
The memory accesses to the target structure are efficient (does not require
bytewise memory accesses) and the atomic pointer update guarantees required by
RCU are kept. u64 is considered as the largest type that can generate a trap for
unaligned accesses (u64 on sparc32 needs to be aligned on 64-bit).
This alignment should be used for both structure definitions and declarations
(as *both* the type and variable attribute) when using the "section"
attribute to generate arrays of structures. Given that gcc only uses the type
attribute "aligned" as a lower-bound for alignment, the structures should not
contain types which require alignment larger than that of u64. The "aligned"
variable attribute, on the other hand, forces gcc to use exactly the specified
alignment.
Also introduce the linker script U64_ALIGN() macro for specification of custom
section alignment that matches that of __u64_aligned.
Changelog since v2:
- Drop the "packed" type attribute, because it causes gcc to drop the padding
between consecutive "int" and "pointer"/"long" fields, which leads to
unaligned accesses on sparc64.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
LKML-Reference: <20110121203642.725191236@efficios.com>
Acked-by: David Miller <davem@davemloft.net>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
include/asm-generic/vmlinux.lds.h | 6 ++++
include/linux/align-section.h | 54 +++++++++++++++++++++++++++++++++++++
include/linux/compiler.h | 2 +
3 files changed, 62 insertions(+), 0 deletions(-)
create mode 100644 include/linux/align-section.h
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 6864933..bdc1688 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -70,6 +70,12 @@
#define STRUCT_ALIGNMENT 32
#define STRUCT_ALIGN() . = ALIGN(STRUCT_ALIGNMENT)
+/*
+ * Align to a 8 byte boundary. For use with custom section made from structures
+ * declared and defined with __u64_aligned.
+ */
+#define U64_ALIGN() . = ALIGN(8)
+
/* The actual configuration determine if the init/exit sections
* are handled as text/data or they can be discarded (which
* often happens at runtime)
diff --git a/include/linux/align-section.h b/include/linux/align-section.h
new file mode 100644
index 0000000..6822a4a
--- /dev/null
+++ b/include/linux/align-section.h
@@ -0,0 +1,54 @@
+#ifndef _LINUX_ALIGN_SECTION_H
+#define _LINUX_ALIGN_SECTION_H
+
+/*
+ * __u64_aligned:
+ *
+ * __u64_aligned should be used as type and variable attribute for structure
+ * definitions when using the "section" attribute to generate arrays of
+ * structures. U64_ALIGN() must be used prior to these section definitions in
+ * the linker script.
+ *
+ * It forces the compiler to use the u64 type alignment, up-aligning or
+ * down-aligning the target type if necessary. The memory accesses to the target
+ * structure are efficient (does not require bytewise memory accesses) and the
+ * atomic pointer update guarantees required by RCU are kept. u64 is considered
+ * as the largest type that can generate a trap for unaligned accesses (u64 on
+ * sparc32 needs to be aligned on 64-bit).
+ *
+ * Given that gcc only uses the type attribute "aligned" as a lower-bound for
+ * alignment, the structures should not contain types which require alignment
+ * larger than that of u64. The "aligned" variable attribute, on the other hand,
+ * forces gcc to use exactly the specified alignment.
+ */
+
+/*
+ * Use __u64_aligned as type and variable attribute for custom section structure
+ * declaration and definition. It should also be applied to any static or
+ * extern definition of the structure that would override the definition to
+ * which the "section" attribute is applied, e.g.
+ *
+ * struct custom {
+ * unsigned long field;
+ * ...
+ * } __u64_aligned;
+ *
+ * extern struct __u64_aligned custom;
+ * struct custom __u64_aligned __attribute__((section("__custom")) identifier;
+ *
+ * The array can then be defined with:
+ *
+ * extern struct custom __start___custom[];
+ * extern struct custom __stop___custom[];
+ *
+ * With linking performed by the linker script:
+ *
+ * U64_ALIGN();
+ * VMLINUX_SYMBOL(__start___custom) = .;
+ * *(__custom)
+ * VMLINUX_SYMBOL(__stop___custom) = .;
+ */
+
+#define __u64_aligned __attribute__((__aligned__(__alignof__(long long))))
+
+#endif /* _LINUX_ALIGN_SECTION_H */
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 320d6c9..5036024 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -57,6 +57,8 @@ extern void __chk_io_ptr(const volatile void __iomem *);
# include <linux/compiler-intel.h>
#endif
+#include <linux/align-section.h>
+
/*
* Generic compiler-dependent macros required for kernel
* build go below this comment. Actual compiler/compiler version
--
1.7.2.3
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH 2/3] tracing: Fix sparc64 alignment crash with __u64_aligned/U64_ALIGN()
2011-01-26 4:04 [PATCH 0/3] [GIT PULL][v2.6.38] tracing: fix unaligned event arrays Steven Rostedt
2011-01-26 4:05 ` [PATCH 1/3] Introduce __u64_aligned and U64_ALIGN() for structure alignment in custom sections Steven Rostedt
@ 2011-01-26 4:05 ` Steven Rostedt
2011-01-26 4:05 ` [PATCH 3/3] tracepoints: Use __u64_aligned/U64_ALIGN() Steven Rostedt
2011-01-26 6:47 ` [PATCH 0/3] [GIT PULL][v2.6.38] tracing: fix unaligned event arrays Ingo Molnar
3 siblings, 0 replies; 11+ messages in thread
From: Steven Rostedt @ 2011-01-26 4:05 UTC (permalink / raw)
To: linux-kernel
Cc: Ingo Molnar, Andrew Morton, Frederic Weisbecker, David Miller,
Mathieu Desnoyers
[-- Attachment #1: 0002-tracing-Fix-sparc64-alignment-crash-with-__u64_align.patch --]
[-- Type: text/plain, Size: 11102 bytes --]
From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Problem description:
gcc happily align structures defined statically on 32-byte. Ftrace trace events
and Tracepoints both statically define structures into sections (using the
"section" attribute), to then assign these to symbols with the linker scripts to
iterate the these sections as an array.
However, gcc uses different alignments for these structures when they are
defined statically and when they are globally visible and/or in an array.
Therefore iteration on these arrays sees "holes" of padding.
Use the __u64_aligned for type declarations and variable definitions to ensure
that gcc:
a) iterates on the correctly aligned type. (type attribute)
b) generates the definitions within the sections with the appropriate alignment.
(variable attribute)
The Ftrace code introduced the "aligned(4)" variable attribute in commit
1473e4417c79f12d91ef91a469699bfa911f510f to try to work around this problem that
showed up on x86_64, but it causes unaligned accesses on sparc64, and is
generally a bad idea on 64-bit if RCU pointers are contained within the
structure. Moreover, it did not use the same attribute as type attribute, which
could cause the iteration on the extern array structure not to match the
variable definitions for some structure sizes.
We should also ensure proper alignment of each Ftrace section in
include/asm-generic/vmlinux.lds.h.
Moving all STRUCT_ALIGN() for FTRACE_EVENTS() and TRACE_SYSCALLS() into the
definitions, so the alignment is only done if these infrastructures are
configured in. Use U64_ALIGN instead of STRUCT_ALIGN.
Also align TRACE_PRINTKS on U64_ALIGN to make sure the beginning of the section
is aligned on pointer size.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
LKML-Reference: <20110121203642.884088920@efficios.com>
Acked-by: David Miller <davem@davemloft.net>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
include/asm-generic/vmlinux.lds.h | 19 ++++++++++---------
include/linux/compiler.h | 6 +++---
include/linux/ftrace_event.h | 2 +-
include/linux/syscalls.h | 12 ++++++------
include/trace/ftrace.h | 8 ++++----
include/trace/syscall.h | 2 +-
kernel/trace/trace.h | 2 +-
kernel/trace/trace_export.c | 2 +-
8 files changed, 27 insertions(+), 26 deletions(-)
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index bdc1688..e4af65c 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -114,7 +114,8 @@
#endif
#ifdef CONFIG_TRACE_BRANCH_PROFILING
-#define LIKELY_PROFILE() VMLINUX_SYMBOL(__start_annotated_branch_profile) = .; \
+#define LIKELY_PROFILE() U64_ALIGN(); \
+ VMLINUX_SYMBOL(__start_annotated_branch_profile) = .; \
*(_ftrace_annotated_branch) \
VMLINUX_SYMBOL(__stop_annotated_branch_profile) = .;
#else
@@ -122,7 +123,8 @@
#endif
#ifdef CONFIG_PROFILE_ALL_BRANCHES
-#define BRANCH_PROFILE() VMLINUX_SYMBOL(__start_branch_profile) = .; \
+#define BRANCH_PROFILE() U64_ALIGN(); \
+ VMLINUX_SYMBOL(__start_branch_profile) = .; \
*(_ftrace_branch) \
VMLINUX_SYMBOL(__stop_branch_profile) = .;
#else
@@ -130,7 +132,8 @@
#endif
#ifdef CONFIG_EVENT_TRACING
-#define FTRACE_EVENTS() VMLINUX_SYMBOL(__start_ftrace_events) = .; \
+#define FTRACE_EVENTS() U64_ALIGN(); \
+ VMLINUX_SYMBOL(__start_ftrace_events) = .; \
*(_ftrace_events) \
VMLINUX_SYMBOL(__stop_ftrace_events) = .;
#else
@@ -138,7 +141,8 @@
#endif
#ifdef CONFIG_TRACING
-#define TRACE_PRINTKS() VMLINUX_SYMBOL(__start___trace_bprintk_fmt) = .; \
+#define TRACE_PRINTKS() U64_ALIGN(); \
+ VMLINUX_SYMBOL(__start___trace_bprintk_fmt) = .; \
*(__trace_printk_fmt) /* Trace_printk fmt' pointer */ \
VMLINUX_SYMBOL(__stop___trace_bprintk_fmt) = .;
#else
@@ -146,7 +150,8 @@
#endif
#ifdef CONFIG_FTRACE_SYSCALLS
-#define TRACE_SYSCALLS() VMLINUX_SYMBOL(__start_syscalls_metadata) = .; \
+#define TRACE_SYSCALLS() U64_ALIGN(); \
+ VMLINUX_SYMBOL(__start_syscalls_metadata) = .; \
*(__syscalls_metadata) \
VMLINUX_SYMBOL(__stop_syscalls_metadata) = .;
#else
@@ -183,11 +188,7 @@
LIKELY_PROFILE() \
BRANCH_PROFILE() \
TRACE_PRINTKS() \
- \
- STRUCT_ALIGN(); \
FTRACE_EVENTS() \
- \
- STRUCT_ALIGN(); \
TRACE_SYSCALLS()
/*
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 5036024..ffd6e7e 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -80,7 +80,7 @@ struct ftrace_branch_data {
};
unsigned long miss_hit[2];
};
-};
+} __u64_aligned;
/*
* Note: DISABLE_BRANCH_PROFILING can be used by special lowlevel code
@@ -96,7 +96,7 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
#define __branch_check__(x, expect) ({ \
int ______r; \
static struct ftrace_branch_data \
- __attribute__((__aligned__(4))) \
+ __u64_aligned \
__attribute__((section("_ftrace_annotated_branch"))) \
______f = { \
.func = __func__, \
@@ -131,7 +131,7 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
({ \
int ______r; \
static struct ftrace_branch_data \
- __attribute__((__aligned__(4))) \
+ __u64_aligned \
__attribute__((section("_ftrace_branch"))) \
______f = { \
.func = __func__, \
diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 47e3997..481a259 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -196,7 +196,7 @@ struct ftrace_event_call {
int perf_refcount;
struct hlist_head __percpu *perf_events;
#endif
-};
+} __u64_aligned;
#define __TRACE_EVENT_FLAGS(name, value) \
static int __init trace_init_flags_##name(void) \
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 18cd068..ea7ab85 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -126,9 +126,9 @@ extern struct trace_event_functions exit_syscall_print_funcs;
#define SYSCALL_TRACE_ENTER_EVENT(sname) \
static struct syscall_metadata \
- __attribute__((__aligned__(4))) __syscall_meta_##sname; \
+ __u64_aligned __syscall_meta_##sname; \
static struct ftrace_event_call __used \
- __attribute__((__aligned__(4))) \
+ __u64_aligned \
__attribute__((section("_ftrace_events"))) \
event_enter_##sname = { \
.name = "sys_enter"#sname, \
@@ -140,9 +140,9 @@ extern struct trace_event_functions exit_syscall_print_funcs;
#define SYSCALL_TRACE_EXIT_EVENT(sname) \
static struct syscall_metadata \
- __attribute__((__aligned__(4))) __syscall_meta_##sname; \
+ __u64_aligned __syscall_meta_##sname; \
static struct ftrace_event_call __used \
- __attribute__((__aligned__(4))) \
+ __u64_aligned \
__attribute__((section("_ftrace_events"))) \
event_exit_##sname = { \
.name = "sys_exit"#sname, \
@@ -156,7 +156,7 @@ extern struct trace_event_functions exit_syscall_print_funcs;
SYSCALL_TRACE_ENTER_EVENT(sname); \
SYSCALL_TRACE_EXIT_EVENT(sname); \
static struct syscall_metadata __used \
- __attribute__((__aligned__(4))) \
+ __u64_aligned \
__attribute__((section("__syscalls_metadata"))) \
__syscall_meta_##sname = { \
.name = "sys"#sname, \
@@ -172,7 +172,7 @@ extern struct trace_event_functions exit_syscall_print_funcs;
SYSCALL_TRACE_ENTER_EVENT(_##sname); \
SYSCALL_TRACE_EXIT_EVENT(_##sname); \
static struct syscall_metadata __used \
- __attribute__((__aligned__(4))) \
+ __u64_aligned \
__attribute__((section("__syscalls_metadata"))) \
__syscall_meta__##sname = { \
.name = "sys_"#sname, \
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index e16610c..ee44cf4 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -69,7 +69,7 @@
#undef DEFINE_EVENT
#define DEFINE_EVENT(template, name, proto, args) \
static struct ftrace_event_call __used \
- __attribute__((__aligned__(4))) event_##name
+ __u64_aligned event_##name;
#undef DEFINE_EVENT_PRINT
#define DEFINE_EVENT_PRINT(template, name, proto, args, print) \
@@ -447,7 +447,7 @@ static inline notrace int ftrace_get_offsets_##call( \
* };
*
* static struct ftrace_event_call __used
- * __attribute__((__aligned__(4)))
+ * __u64_aligned
* __attribute__((section("_ftrace_events"))) event_<call> = {
* .name = "<call>",
* .class = event_class_<template>,
@@ -580,7 +580,7 @@ static struct ftrace_event_class __used event_class_##call = { \
#define DEFINE_EVENT(template, call, proto, args) \
\
static struct ftrace_event_call __used \
-__attribute__((__aligned__(4))) \
+__u64_aligned \
__attribute__((section("_ftrace_events"))) event_##call = { \
.name = #call, \
.class = &event_class_##template, \
@@ -594,7 +594,7 @@ __attribute__((section("_ftrace_events"))) event_##call = { \
static const char print_fmt_##call[] = print; \
\
static struct ftrace_event_call __used \
-__attribute__((__aligned__(4))) \
+__u64_aligned \
__attribute__((section("_ftrace_events"))) event_##call = { \
.name = #call, \
.class = &event_class_##template, \
diff --git a/include/trace/syscall.h b/include/trace/syscall.h
index 31966a4..69578b3 100644
--- a/include/trace/syscall.h
+++ b/include/trace/syscall.h
@@ -29,7 +29,7 @@ struct syscall_metadata {
struct ftrace_event_call *enter_event;
struct ftrace_event_call *exit_event;
-};
+} __u64_aligned;
#ifdef CONFIG_FTRACE_SYSCALLS
extern unsigned long arch_syscall_addr(int nr);
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 9021f8c..6a08891 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -749,7 +749,7 @@ extern const char *__stop___trace_bprintk_fmt[];
#undef FTRACE_ENTRY
#define FTRACE_ENTRY(call, struct_name, id, tstruct, print) \
extern struct ftrace_event_call \
- __attribute__((__aligned__(4))) event_##call;
+ __u64_aligned event_##call;
#undef FTRACE_ENTRY_DUP
#define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print) \
FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c
index 4b74d71..a6ebf4e 100644
--- a/kernel/trace/trace_export.c
+++ b/kernel/trace/trace_export.c
@@ -162,7 +162,7 @@ struct ftrace_event_class event_class_ftrace_##call = { \
}; \
\
struct ftrace_event_call __used \
-__attribute__((__aligned__(4))) \
+__u64_aligned \
__attribute__((section("_ftrace_events"))) event_##call = { \
.name = #call, \
.event.type = etype, \
--
1.7.2.3
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH 3/3] tracepoints: Use __u64_aligned/U64_ALIGN()
2011-01-26 4:04 [PATCH 0/3] [GIT PULL][v2.6.38] tracing: fix unaligned event arrays Steven Rostedt
2011-01-26 4:05 ` [PATCH 1/3] Introduce __u64_aligned and U64_ALIGN() for structure alignment in custom sections Steven Rostedt
2011-01-26 4:05 ` [PATCH 2/3] tracing: Fix sparc64 alignment crash with __u64_aligned/U64_ALIGN() Steven Rostedt
@ 2011-01-26 4:05 ` Steven Rostedt
2011-01-27 18:19 ` Jiri Olsa
2011-01-26 6:47 ` [PATCH 0/3] [GIT PULL][v2.6.38] tracing: fix unaligned event arrays Ingo Molnar
3 siblings, 1 reply; 11+ messages in thread
From: Steven Rostedt @ 2011-01-26 4:05 UTC (permalink / raw)
To: linux-kernel
Cc: Ingo Molnar, Andrew Morton, Frederic Weisbecker, David Miller,
Mathieu Desnoyers
[-- Attachment #1: 0003-tracepoints-Use-__u64_aligned-U64_ALIGN.patch --]
[-- Type: text/plain, Size: 3428 bytes --]
From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
commit 7e066fb870fcd1025ec3ba7bbde5d541094f4ce1 added the aligned(32) type and
variable attribute to the tracepoint structures to deal with gcc happily
aligning statically defined structures on 32-byte multiples.
Working on issues within Ftrace, we came up with __64_aligned, which deals with
this issue more elegantly by forcing an 8-byte alignment to both the type
declaration and variable definition.
This therefore saves space, bringing down the size of struct tracepoint from 64
bytes to 38 on 64-bit architectures.
Updating:
- The type attribute (for iteration over the struct tracepoint array)
- Added the variable attribute to the extern definition (needed to force gcc to
consider this alignment for the following definition)
- The definition variable attribute (to force gcc to this specific alignment for
the static definitions)
- The linker script (8-byte alignment can now replace the previous 32-byte
alignment for the custom tracepoint section)
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
LKML-Reference: <20110121203643.046218322@efficios.com>
Acked-by: David Miller <davem@davemloft.net>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
include/asm-generic/vmlinux.lds.h | 2 +-
include/linux/tracepoint.h | 12 ++++--------
2 files changed, 5 insertions(+), 9 deletions(-)
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index e4af65c..95abb5f 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -176,7 +176,7 @@
CPU_KEEP(exit.data) \
MEM_KEEP(init.data) \
MEM_KEEP(exit.data) \
- . = ALIGN(32); \
+ U64_ALIGN(); \
VMLINUX_SYMBOL(__start___tracepoints) = .; \
*(__tracepoints) \
VMLINUX_SYMBOL(__stop___tracepoints) = .; \
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index c681461..4bc50ea 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -33,12 +33,7 @@ struct tracepoint {
void (*regfunc)(void);
void (*unregfunc)(void);
struct tracepoint_func __rcu *funcs;
-} __attribute__((aligned(32))); /*
- * Aligned on 32 bytes because it is
- * globally visible and gcc happily
- * align these on the structure size.
- * Keep in sync with vmlinux.lds.h.
- */
+} __u64_aligned;
/*
* Connect a probe to a tracepoint.
@@ -146,7 +141,7 @@ static inline void tracepoint_update_probe_range(struct tracepoint *begin,
* structure. Force alignment to the same alignment as the section start.
*/
#define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args) \
- extern struct tracepoint __tracepoint_##name; \
+ extern struct tracepoint __u64_aligned __tracepoint_##name; \
static inline void trace_##name(proto) \
{ \
JUMP_LABEL(&__tracepoint_##name.state, do_trace); \
@@ -178,7 +173,8 @@ do_trace: \
static const char __tpstrtab_##name[] \
__attribute__((section("__tracepoints_strings"))) = #name; \
struct tracepoint __tracepoint_##name \
- __attribute__((section("__tracepoints"), aligned(32))) = \
+ __u64_aligned \
+ __attribute__((section("__tracepoints"))) = \
{ __tpstrtab_##name, 0, reg, unreg, NULL }
#define DEFINE_TRACE(name) \
--
1.7.2.3
^ permalink raw reply related [flat|nested] 11+ messages in thread