[Xen-devel] [PATCH for-4.6] tools/xenstore: Correct use of va_end() after va_copy()

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

C requires that every use of va_copy() is matched with a va_end() call.

This is especially important for x86_64 as va_{start,copy}() may need to
allocate memory to generate a va_list containing parameters which were
previously in registers.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Ian Campbell <Ian.Campbell@xxxxxxxxxx>
CC: Ian Jackson <Ian.Jackson@xxxxxxxxxxxxx>
CC: Wei Liu <wei.liu2@xxxxxxxxxx>
---
 tools/xenstore/talloc.c |    6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tools/xenstore/talloc.c b/tools/xenstore/talloc.c
index 54dbd02..d7edcf3 100644
--- a/tools/xenstore/talloc.c
+++ b/tools/xenstore/talloc.c
@@ -1101,13 +1101,16 @@ char *talloc_vasprintf(const void *t, const char *fmt, 
va_list ap)
 
        /* this call looks strange, but it makes it work on older solaris boxes 
*/
        if ((len = vsnprintf(&c, 1, fmt, ap2)) < 0) {
+               va_end(ap2);
                return NULL;
        }
+       va_end(ap2);
 
        ret = _talloc(t, len+1);
        if (ret) {
                VA_COPY(ap2, ap);
                vsnprintf(ret, len+1, fmt, ap2);
+               va_end(ap2);
                talloc_set_name_const(ret, ret);
        }
 
@@ -1161,8 +1164,10 @@ static char *talloc_vasprintf_append(char *s, const char 
*fmt, va_list ap)
                 * the original string. Most current callers of this 
                 * function expect it to never return NULL.
                 */
+               va_end(ap2);
                return s;
        }
+       va_end(ap2);
 
        s = talloc_realloc(NULL, s, char, s_len + len+1);
        if (!s) return NULL;
@@ -1170,6 +1175,7 @@ static char *talloc_vasprintf_append(char *s, const char 
*fmt, va_list ap)
        VA_COPY(ap2, ap);
 
        vsnprintf(s+s_len, len+1, fmt, ap2);
+       va_end(ap2);
        talloc_set_name_const(s, s);
 
        return s;
-- 
1.7.10.4


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