* [PATCH][2.6] WARN_ON_STACK_VAR aka fighting variable lifetime bugs
@ 2003-08-09 19:29 Zwane Mwaikambo
2003-08-09 19:33 ` Zwane Mwaikambo
2003-08-11 18:43 ` David Mosberger
0 siblings, 2 replies; 4+ messages in thread
From: Zwane Mwaikambo @ 2003-08-09 19:29 UTC (permalink / raw)
To: Linux Kernel; +Cc: William Lee Irwin III, Bartlomiej Zolnierkiewicz, Jens Axboe
This macro allows us to detect whether a variable is on the stack or not.
Originally devised to help detect some strange IDE/elevator bugs Bill and
myself came across in the -wli tree. My apologies as it's simply cut and
paste for the other architectures, hopefully it doesn't break on
something badly, i don't know them all that well.
asm-alpha/bug.h | 4 ++++
asm-arm/bug.h | 4 ++++
asm-arm26/bug.h | 4 ++++
asm-cris/bug.h | 4 ++++
asm-h8300/bug.h | 4 ++++
asm-i386/bug.h | 4 ++++
asm-ia64/bug.h | 4 ++++
asm-m68k/bug.h | 4 ++++
asm-m68knommu/bug.h | 4 ++++
asm-mips/bug.h | 4 ++++
asm-mips64/bug.h | 4 ++++
asm-parisc/bug.h | 4 ++++
asm-ppc/bug.h | 4 ++++
asm-ppc64/bug.h | 4 ++++
asm-s390/bug.h | 4 ++++
asm-sh/bug.h | 4 ++++
asm-sparc/bug.h | 4 ++++
asm-sparc64/bug.h | 4 ++++
asm-um/bug.h | 4 ++++
asm-v850/bug.h | 4 ++++
asm-x86_64/bug.h | 4 ++++
21 files changed, 84 insertions(+)
Index: linux-2.6.0-test2-irq/include/asm-alpha/bug.h
===================================================================
RCS file: /build/cvsroot/linux-2.6.0-test2/include/asm-alpha/bug.h,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 bug.h
--- linux-2.6.0-test2-irq/include/asm-alpha/bug.h 30 Jul 2003 00:06:37 -0000 1.1.1.1
+++ linux-2.6.0-test2-irq/include/asm-alpha/bug.h 9 Aug 2003 19:14:55 -0000
@@ -20,4 +20,8 @@
} \
} while (0)
+#define WARN_ON_STACK_VAR(ptr) do { \
+ unsigned long __ti = (unsigned long)current_thread_info(); \
+ WARN_ON((__ti & (unsigned long)(ptr)) == __ti); \
+} while (0)
#endif
Index: linux-2.6.0-test2-irq/include/asm-arm/bug.h
===================================================================
RCS file: /build/cvsroot/linux-2.6.0-test2/include/asm-arm/bug.h,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 bug.h
--- linux-2.6.0-test2-irq/include/asm-arm/bug.h 30 Jul 2003 00:06:36 -0000 1.1.1.1
+++ linux-2.6.0-test2-irq/include/asm-arm/bug.h 9 Aug 2003 19:14:42 -0000
@@ -27,4 +27,8 @@ extern volatile void __bug(const char *f
} \
} while (0)
+#define WARN_ON_STACK_VAR(ptr) do { \
+ unsigned long __ti = (unsigned long)current_thread_info(); \
+ WARN_ON((__ti & (unsigned long)(ptr)) == __ti); \
+} while (0)
#endif
Index: linux-2.6.0-test2-irq/include/asm-arm26/bug.h
===================================================================
RCS file: /build/cvsroot/linux-2.6.0-test2/include/asm-arm26/bug.h,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 bug.h
--- linux-2.6.0-test2-irq/include/asm-arm26/bug.h 30 Jul 2003 00:06:39 -0000 1.1.1.1
+++ linux-2.6.0-test2-irq/include/asm-arm26/bug.h 9 Aug 2003 19:14:33 -0000
@@ -27,4 +27,8 @@ extern volatile void __bug(const char *f
} \
} while (0)
+#define WARN_ON_STACK_VAR(ptr) do { \
+ unsigned long __ti = (unsigned long)current_thread_info(); \
+ WARN_ON((__ti & (unsigned long)(ptr)) == __ti); \
+} while (0)
#endif
Index: linux-2.6.0-test2-irq/include/asm-cris/bug.h
===================================================================
RCS file: /build/cvsroot/linux-2.6.0-test2/include/asm-cris/bug.h,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 bug.h
--- linux-2.6.0-test2-irq/include/asm-cris/bug.h 30 Jul 2003 00:06:39 -0000 1.1.1.1
+++ linux-2.6.0-test2-irq/include/asm-cris/bug.h 9 Aug 2003 19:14:25 -0000
@@ -18,4 +18,8 @@
} \
} while (0)
+#define WARN_ON_STACK_VAR(ptr) do { \
+ unsigned long __ti = (unsigned long)current_thread_info(); \
+ WARN_ON((__ti & (unsigned long)(ptr)) == __ti); \
+} while (0)
#endif
Index: linux-2.6.0-test2-irq/include/asm-h8300/bug.h
===================================================================
RCS file: /build/cvsroot/linux-2.6.0-test2/include/asm-h8300/bug.h,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 bug.h
--- linux-2.6.0-test2-irq/include/asm-h8300/bug.h 30 Jul 2003 00:06:37 -0000 1.1.1.1
+++ linux-2.6.0-test2-irq/include/asm-h8300/bug.h 9 Aug 2003 19:14:18 -0000
@@ -18,4 +18,8 @@
} \
} while (0)
+#define WARN_ON_STACK_VAR(ptr) do { \
+ unsigned long __ti = (unsigned long)current_thread_info(); \
+ WARN_ON((__ti & (unsigned long)(ptr)) == __ti); \
+} while (0)
#endif
Index: linux-2.6.0-test2-irq/include/asm-i386/bug.h
===================================================================
RCS file: /build/cvsroot/linux-2.6.0-test2/include/asm-i386/bug.h,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 bug.h
--- linux-2.6.0-test2-irq/include/asm-i386/bug.h 30 Jul 2003 00:06:38 -0000 1.1.1.1
+++ linux-2.6.0-test2-irq/include/asm-i386/bug.h 9 Aug 2003 16:28:34 -0000
@@ -32,4 +32,8 @@
} \
} while (0)
+#define WARN_ON_STACK_VAR(ptr) do { \
+ unsigned long __ti = (unsigned long)current_thread_info(); \
+ WARN_ON((__ti & (unsigned long)(ptr)) == __ti); \
+} while (0)
#endif
Index: linux-2.6.0-test2-irq/include/asm-ia64/bug.h
===================================================================
RCS file: /build/cvsroot/linux-2.6.0-test2/include/asm-ia64/bug.h,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 bug.h
--- linux-2.6.0-test2-irq/include/asm-ia64/bug.h 30 Jul 2003 00:06:30 -0000 1.1.1.1
+++ linux-2.6.0-test2-irq/include/asm-ia64/bug.h 9 Aug 2003 19:14:09 -0000
@@ -19,4 +19,8 @@
} \
} while (0)
+#define WARN_ON_STACK_VAR(ptr) do { \
+ unsigned long __ti = (unsigned long)current_thread_info(); \
+ WARN_ON((__ti & (unsigned long)(ptr)) == __ti); \
+} while (0)
#endif
Index: linux-2.6.0-test2-irq/include/asm-m68k/bug.h
===================================================================
RCS file: /build/cvsroot/linux-2.6.0-test2/include/asm-m68k/bug.h,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 bug.h
--- linux-2.6.0-test2-irq/include/asm-m68k/bug.h 30 Jul 2003 00:06:32 -0000 1.1.1.1
+++ linux-2.6.0-test2-irq/include/asm-m68k/bug.h 9 Aug 2003 19:14:00 -0000
@@ -37,4 +37,8 @@
} \
} while (0)
+#define WARN_ON_STACK_VAR(ptr) do { \
+ unsigned long __ti = (unsigned long)current_thread_info(); \
+ WARN_ON((__ti & (unsigned long)(ptr)) == __ti); \
+} while (0)
#endif
Index: linux-2.6.0-test2-irq/include/asm-m68knommu/bug.h
===================================================================
RCS file: /build/cvsroot/linux-2.6.0-test2/include/asm-m68knommu/bug.h,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 bug.h
--- linux-2.6.0-test2-irq/include/asm-m68knommu/bug.h 30 Jul 2003 00:06:32 -0000 1.1.1.1
+++ linux-2.6.0-test2-irq/include/asm-m68knommu/bug.h 9 Aug 2003 19:09:11 -0000
@@ -21,4 +21,8 @@
} \
} while (0)
+#define WARN_ON_STACK_VAR(ptr) do { \
+ unsigned long __ti = (unsigned long)current_thread_info(); \
+ WARN_ON((__ti & (unsigned long)(ptr)) == __ti); \
+} while (0)
#endif
Index: linux-2.6.0-test2-irq/include/asm-mips/bug.h
===================================================================
RCS file: /build/cvsroot/linux-2.6.0-test2/include/asm-mips/bug.h,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 bug.h
--- linux-2.6.0-test2-irq/include/asm-mips/bug.h 30 Jul 2003 00:06:29 -0000 1.1.1.1
+++ linux-2.6.0-test2-irq/include/asm-mips/bug.h 9 Aug 2003 19:09:01 -0000
@@ -18,4 +18,8 @@ do { \
} \
} while (0)
+#define WARN_ON_STACK_VAR(ptr) do { \
+ unsigned long __ti = (unsigned long)current_thread_info(); \
+ WARN_ON((__ti & (unsigned long)(ptr)) == __ti); \
+} while (0)
#endif
Index: linux-2.6.0-test2-irq/include/asm-mips64/bug.h
===================================================================
RCS file: /build/cvsroot/linux-2.6.0-test2/include/asm-mips64/bug.h,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 bug.h
--- linux-2.6.0-test2-irq/include/asm-mips64/bug.h 30 Jul 2003 00:06:30 -0000 1.1.1.1
+++ linux-2.6.0-test2-irq/include/asm-mips64/bug.h 9 Aug 2003 19:08:53 -0000
@@ -18,4 +18,8 @@ do { \
} \
} while (0)
+#define WARN_ON_STACK_VAR(ptr) do { \
+ unsigned long __ti = (unsigned long)current_thread_info(); \
+ WARN_ON((__ti & (unsigned long)(ptr)) == __ti); \
+} while (0)
#endif
Index: linux-2.6.0-test2-irq/include/asm-parisc/bug.h
===================================================================
RCS file: /build/cvsroot/linux-2.6.0-test2/include/asm-parisc/bug.h,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 bug.h
--- linux-2.6.0-test2-irq/include/asm-parisc/bug.h 30 Jul 2003 00:06:32 -0000 1.1.1.1
+++ linux-2.6.0-test2-irq/include/asm-parisc/bug.h 9 Aug 2003 19:08:46 -0000
@@ -26,4 +26,8 @@
} \
} while (0)
+#define WARN_ON_STACK_VAR(ptr) do { \
+ unsigned long __ti = (unsigned long)current_thread_info(); \
+ WARN_ON((__ti & (unsigned long)(ptr)) == __ti); \
+} while (0)
#endif
Index: linux-2.6.0-test2-irq/include/asm-ppc/bug.h
===================================================================
RCS file: /build/cvsroot/linux-2.6.0-test2/include/asm-ppc/bug.h,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 bug.h
--- linux-2.6.0-test2-irq/include/asm-ppc/bug.h 30 Jul 2003 00:06:31 -0000 1.1.1.1
+++ linux-2.6.0-test2-irq/include/asm-ppc/bug.h 9 Aug 2003 19:08:38 -0000
@@ -45,4 +45,8 @@ struct bug_entry {
"i" (__FILE__), "i" (__FUNCTION__)); \
} while (0)
+#define WARN_ON_STACK_VAR(ptr) do { \
+ unsigned long __ti = (unsigned long)current_thread_info(); \
+ WARN_ON((__ti & (unsigned long)(ptr)) == __ti); \
+} while (0)
#endif
Index: linux-2.6.0-test2-irq/include/asm-ppc64/bug.h
===================================================================
RCS file: /build/cvsroot/linux-2.6.0-test2/include/asm-ppc64/bug.h,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 bug.h
--- linux-2.6.0-test2-irq/include/asm-ppc64/bug.h 30 Jul 2003 00:06:28 -0000 1.1.1.1
+++ linux-2.6.0-test2-irq/include/asm-ppc64/bug.h 9 Aug 2003 19:07:25 -0000
@@ -55,5 +55,9 @@ struct bug_entry {
"i" (__FILE__), "i" (__FUNCTION__)); \
} while (0)
+#define WARN_ON_STACK_VAR(ptr) do { \
+ unsigned long __ti = (unsigned long)current_thread_info(); \
+ WARN_ON((__ti & (unsigned long)(ptr)) == __ti); \
+} while (0)
#endif
#endif
Index: linux-2.6.0-test2-irq/include/asm-s390/bug.h
===================================================================
RCS file: /build/cvsroot/linux-2.6.0-test2/include/asm-s390/bug.h,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 bug.h
--- linux-2.6.0-test2-irq/include/asm-s390/bug.h 30 Jul 2003 00:06:38 -0000 1.1.1.1
+++ linux-2.6.0-test2-irq/include/asm-s390/bug.h 9 Aug 2003 19:06:51 -0000
@@ -22,4 +22,8 @@
} \
} while (0)
+#define WARN_ON_STACK_VAR(ptr) do { \
+ unsigned long __ti = (unsigned long)current_thread_info(); \
+ WARN_ON((__ti & (unsigned long)(ptr)) == __ti); \
+} while (0)
#endif
Index: linux-2.6.0-test2-irq/include/asm-sh/bug.h
===================================================================
RCS file: /build/cvsroot/linux-2.6.0-test2/include/asm-sh/bug.h,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 bug.h
--- linux-2.6.0-test2-irq/include/asm-sh/bug.h 30 Jul 2003 00:06:39 -0000 1.1.1.1
+++ linux-2.6.0-test2-irq/include/asm-sh/bug.h 9 Aug 2003 19:06:43 -0000
@@ -27,4 +27,8 @@
} \
} while (0)
+#define WARN_ON_STACK_VAR(ptr) do { \
+ unsigned long __ti = (unsigned long)current_thread_info(); \
+ WARN_ON((__ti & (unsigned long)(ptr)) == __ti); \
+} while (0)
#endif
Index: linux-2.6.0-test2-irq/include/asm-sparc/bug.h
===================================================================
RCS file: /build/cvsroot/linux-2.6.0-test2/include/asm-sparc/bug.h,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 bug.h
--- linux-2.6.0-test2-irq/include/asm-sparc/bug.h 30 Jul 2003 00:06:37 -0000 1.1.1.1
+++ linux-2.6.0-test2-irq/include/asm-sparc/bug.h 9 Aug 2003 19:06:34 -0000
@@ -41,4 +41,8 @@ extern void do_BUG(const char *file, int
} \
} while (0)
+#define WARN_ON_STACK_VAR(ptr) do { \
+ unsigned long __ti = (unsigned long)current_thread_info(); \
+ WARN_ON((__ti & (unsigned long)(ptr)) == __ti); \
+} while (0)
#endif
Index: linux-2.6.0-test2-irq/include/asm-sparc64/bug.h
===================================================================
RCS file: /build/cvsroot/linux-2.6.0-test2/include/asm-sparc64/bug.h,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 bug.h
--- linux-2.6.0-test2-irq/include/asm-sparc64/bug.h 30 Jul 2003 00:06:38 -0000 1.1.1.1
+++ linux-2.6.0-test2-irq/include/asm-sparc64/bug.h 9 Aug 2003 19:06:22 -0000
@@ -29,4 +29,8 @@ extern void do_BUG(const char *file, int
} \
} while (0)
+#define WARN_ON_STACK_VAR(ptr) do { \
+ unsigned long __ti = (unsigned long)current_thread_info(); \
+ WARN_ON((__ti & (unsigned long)(ptr)) == __ti); \
+} while (0)
#endif
Index: linux-2.6.0-test2-irq/include/asm-um/bug.h
===================================================================
RCS file: /build/cvsroot/linux-2.6.0-test2/include/asm-um/bug.h,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 bug.h
--- linux-2.6.0-test2-irq/include/asm-um/bug.h 30 Jul 2003 00:06:35 -0000 1.1.1.1
+++ linux-2.6.0-test2-irq/include/asm-um/bug.h 9 Aug 2003 19:05:28 -0000
@@ -27,4 +27,8 @@ extern int foo;
#endif
+#define WARN_ON_STACK_VAR(ptr) do { \
+ unsigned long __ti = (unsigned long)current_thread_info(); \
+ WARN_ON((__ti & (unsigned long)(ptr)) == __ti); \
+} while (0)
#endif
Index: linux-2.6.0-test2-irq/include/asm-v850/bug.h
===================================================================
RCS file: /build/cvsroot/linux-2.6.0-test2/include/asm-v850/bug.h,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 bug.h
--- linux-2.6.0-test2-irq/include/asm-v850/bug.h 30 Jul 2003 00:06:39 -0000 1.1.1.1
+++ linux-2.6.0-test2-irq/include/asm-v850/bug.h 9 Aug 2003 19:05:19 -0000
@@ -27,4 +27,8 @@ extern void __bug (void) __attribute__ (
} \
} while (0)
+#define WARN_ON_STACK_VAR(ptr) do { \
+ unsigned long __ti = (unsigned long)current_thread_info(); \
+ WARN_ON((__ti & (unsigned long)(ptr)) == __ti); \
+} while (0)
#endif /* __V850_BUG_H__ */
Index: linux-2.6.0-test2-irq/include/asm-x86_64/bug.h
===================================================================
RCS file: /build/cvsroot/linux-2.6.0-test2/include/asm-x86_64/bug.h,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 bug.h
--- linux-2.6.0-test2-irq/include/asm-x86_64/bug.h 30 Jul 2003 00:06:30 -0000 1.1.1.1
+++ linux-2.6.0-test2-irq/include/asm-x86_64/bug.h 9 Aug 2003 19:05:06 -0000
@@ -29,4 +29,8 @@ void out_of_line_bug(void);
} \
} while (0)
+#define WARN_ON_STACK_VAR(ptr) do { \
+ unsigned long __ti = (unsigned long)current_thread_info(); \
+ WARN_ON((__ti & (unsigned long)(ptr)) == __ti); \
+} while (0)
#endif
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH][2.6] WARN_ON_STACK_VAR aka fighting variable lifetime bugs
2003-08-09 19:29 [PATCH][2.6] WARN_ON_STACK_VAR aka fighting variable lifetime bugs Zwane Mwaikambo
@ 2003-08-09 19:33 ` Zwane Mwaikambo
2003-08-11 18:43 ` David Mosberger
1 sibling, 0 replies; 4+ messages in thread
From: Zwane Mwaikambo @ 2003-08-09 19:33 UTC (permalink / raw)
To: Linux Kernel; +Cc: William Lee Irwin III, Bartlomiej Zolnierkiewicz, Jens Axboe
This patch adds some elevator checks for stack variables, there are
in fact some in theory in the ide_do_drive_cmd path when the caller passes
args via rq->special as a stack variable and does not call with ide_wait*.
Index: linux-2.6-wli/drivers/block/elevator.c
===================================================================
RCS file: /home/cvs/linux-2.5/drivers/block/elevator.c,v
retrieving revision 1.48
diff -u -p -B -r1.48 elevator.c
--- linux-2.6-wli/drivers/block/elevator.c 27 Jul 2003 01:42:20 -0000 1.48
+++ linux-2.6-wli/drivers/block/elevator.c 9 Aug 2003 18:16:09 -0000
@@ -230,6 +230,11 @@ void __elv_add_request(request_queue_t *
{
struct list_head *insert = &q->queue_head;
+ if (!rq->waiting) {
+ WARN_ON_STACK_VAR(rq);
+ WARN_ON_STACK_VAR(rq->special);
+ }
+
if (at_end)
insert = insert->prev;
if (plug)
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH][2.6] WARN_ON_STACK_VAR aka fighting variable lifetime bugs
2003-08-11 18:43 ` David Mosberger
@ 2003-08-11 18:41 ` Zwane Mwaikambo
0 siblings, 0 replies; 4+ messages in thread
From: Zwane Mwaikambo @ 2003-08-11 18:41 UTC (permalink / raw)
To: davidm
Cc: Linux Kernel, William Lee Irwin III, Bartlomiej Zolnierkiewicz,
Jens Axboe
On Mon, 11 Aug 2003, David Mosberger wrote:
> >>>>> On Sat, 9 Aug 2003 15:29:41 -0400 (EDT), Zwane Mwaikambo <zwane@arm.linux.org.uk> said:
>
> Zwane> --- linux-2.6.0-test2-irq/include/asm-ia64/bug.h 30 Jul 2003 00:06:30 -0000 1.1.1.1
> Zwane> +++ linux-2.6.0-test2-irq/include/asm-ia64/bug.h 9 Aug 2003 19:14:09 -0000
> Zwane> +#define WARN_ON_STACK_VAR(ptr) do { \
> Zwane> + unsigned long __ti = (unsigned long)current_thread_info(); \
> Zwane> + WARN_ON((__ti & (unsigned long)(ptr)) == __ti); \
> Zwane> +} while (0)
>
> Note that on ia64 we don't use bit-masking to calculate the
> task-pointer. Instead, thread-info follows the task structure. This
> is done such that the task-structure, thread-info, and kernel stack
> can be mapped by a single (pinned) TLB entry.
>
> The correct check for a variable being on the stack of the current
> task would be something like this:
>
> ((unsigned long)(ptr) - (unsigned long) current) < IA64_STK_OFFSET
>
> (IA64_STK_OFFSET is declared by <asm/ptrace.h>).
Ah thanks =) i've modified my patch accordingly.
Zwane
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH][2.6] WARN_ON_STACK_VAR aka fighting variable lifetime bugs
2003-08-09 19:29 [PATCH][2.6] WARN_ON_STACK_VAR aka fighting variable lifetime bugs Zwane Mwaikambo
2003-08-09 19:33 ` Zwane Mwaikambo
@ 2003-08-11 18:43 ` David Mosberger
2003-08-11 18:41 ` Zwane Mwaikambo
1 sibling, 1 reply; 4+ messages in thread
From: David Mosberger @ 2003-08-11 18:43 UTC (permalink / raw)
To: Zwane Mwaikambo
Cc: Linux Kernel, William Lee Irwin III, Bartlomiej Zolnierkiewicz,
Jens Axboe
>>>>> On Sat, 9 Aug 2003 15:29:41 -0400 (EDT), Zwane Mwaikambo <zwane@arm.linux.org.uk> said:
Zwane> --- linux-2.6.0-test2-irq/include/asm-ia64/bug.h 30 Jul 2003 00:06:30 -0000 1.1.1.1
Zwane> +++ linux-2.6.0-test2-irq/include/asm-ia64/bug.h 9 Aug 2003 19:14:09 -0000
Zwane> +#define WARN_ON_STACK_VAR(ptr) do { \
Zwane> + unsigned long __ti = (unsigned long)current_thread_info(); \
Zwane> + WARN_ON((__ti & (unsigned long)(ptr)) == __ti); \
Zwane> +} while (0)
Note that on ia64 we don't use bit-masking to calculate the
task-pointer. Instead, thread-info follows the task structure. This
is done such that the task-structure, thread-info, and kernel stack
can be mapped by a single (pinned) TLB entry.
The correct check for a variable being on the stack of the current
task would be something like this:
((unsigned long)(ptr) - (unsigned long) current) < IA64_STK_OFFSET
(IA64_STK_OFFSET is declared by <asm/ptrace.h>).
Thanks,
--david
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2003-08-11 19:33 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2003-08-09 19:29 [PATCH][2.6] WARN_ON_STACK_VAR aka fighting variable lifetime bugs Zwane Mwaikambo
2003-08-09 19:33 ` Zwane Mwaikambo
2003-08-11 18:43 ` David Mosberger
2003-08-11 18:41 ` Zwane Mwaikambo
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