[libvirt] [PATCH v1 01/15] virmock: Initialize both symbols in VIR_MOCK_REAL_INIT_ALT

Michal Privoznik mprivozn at redhat.com
Wed Feb 27 10:04:33 UTC 2019


It may happen that both symbols are present. Especially when
chaining mocks. For instance if a test is using virpcimock and
then both stat and __xstat would be present in the address space
as virpcimock implements both. Then, if the test would try to use
say virfilewrapper (which again uses VIR_MOCK_REAL_INIT_ALT() to
init real_stat and real___xstat) it would find stat() from
virpcimock and stop there. The virfilewrapper.c:real___xstat
wouldn't be initialized and thus it may result in a segfault.

The reason for segfault is that sys/stat.h may redefine stat() to
call __xstat().

Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
---
 tests/virmock.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tests/virmock.h b/tests/virmock.h
index 853dbb8be2..9c7ecf60ce 100644
--- a/tests/virmock.h
+++ b/tests/virmock.h
@@ -292,8 +292,9 @@
 
 # define VIR_MOCK_REAL_INIT_ALT(name1, name2) \
     do { \
-        if (!(real_ ## name1 = dlsym(RTLD_NEXT, #name1)) && \
-            !(real_ ## name2 = dlsym(RTLD_NEXT, #name2))) { \
+        real_ ## name1 = dlsym(RTLD_NEXT, #name1); \
+        real_ ## name2 = dlsym(RTLD_NEXT, #name2); \
+        if (!real_##name1 && !real_##name2) { \
             fprintf(stderr, "Cannot find real '%s' or '%s' symbol\n", \
                     #name1, #name2); \
             abort(); \
-- 
2.19.2




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