* [PATCH] Revert to old glibc behaviour for vsnprintf used in emit_to_buffer function
@ 2010-09-13 14:36 Peter Rajnoha
2010-09-20 12:35 ` Alasdair G Kergon
0 siblings, 1 reply; 2+ messages in thread
From: Peter Rajnoha @ 2010-09-13 14:36 UTC (permalink / raw)
To: lvm-devel
Revert to old glibc behaviour for vsnprintf used in emit_to_buffer fn.
Otherwise, the check that follows would be wrong for new glibc versions.
(This caused the bug #633033 to be undetected and pass throught the check,
corrupting the metadata!)
Peter
---
lib/misc/lvm-string.c | 8 ++++++++
1 files changed, 8 insertions(+), 0 deletions(-)
diff --git a/lib/misc/lvm-string.c b/lib/misc/lvm-string.c
index 7eed799..82a3e94 100644
--- a/lib/misc/lvm-string.c
+++ b/lib/misc/lvm-string.c
@@ -27,6 +27,14 @@ int emit_to_buffer(char **buffer, size_t *size, const char *fmt, ...)
n = vsnprintf(*buffer, *size, fmt, ap);
va_end(ap);
+ /*
+ * Revert to old glibc behaviour (version <= 2.0.6) where snprintf
+ * returned -1 if buffer was too small. From glibc 2.1 it returns number
+ * of chars that would have been written had there been room.
+ */
+ if (n < 0 || ((unsigned) n + 1 > *size))
+ n = -1;
+
if (n < 0 || ((size_t)n == *size))
return 0;
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH] Revert to old glibc behaviour for vsnprintf used in emit_to_buffer function
2010-09-13 14:36 [PATCH] Revert to old glibc behaviour for vsnprintf used in emit_to_buffer function Peter Rajnoha
@ 2010-09-20 12:35 ` Alasdair G Kergon
0 siblings, 0 replies; 2+ messages in thread
From: Alasdair G Kergon @ 2010-09-20 12:35 UTC (permalink / raw)
To: lvm-devel
On Mon, Sep 13, 2010 at 04:36:10PM +0200, Peter Rajnoha wrote:
> Revert to old glibc behaviour for vsnprintf used in emit_to_buffer fn.
> Otherwise, the check that follows would be wrong for new glibc versions.
Ack.
Alasdair
^ permalink raw reply [flat|nested] 2+ messages in thread
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2010-09-13 14:36 [PATCH] Revert to old glibc behaviour for vsnprintf used in emit_to_buffer function Peter Rajnoha
2010-09-20 12:35 ` Alasdair G Kergon
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