[patch] Fixed occasional failure to load a custom shared library

Jan Kratochvil
2006-06-22T11:40:36Z

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Hi,

https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=146810

Inferior ENV{"LD_LIBRARY_PATH"} and/or ENV{"PATH"} may get ignored by
solib_open() resulting in
Error while mapping shared library sections:
libc++test4dl.so: Success.
and afterwards while calling a function from the shared library it crashes:
(gdb) call randomthing()
Program received signal SIGSEGV, Segmentation fault.
randomthing () at c++test4dl.cxx:3
3 void randomthing()
The program being debugged was signaled while in a function called from GDB.

Trivia NULL vs. "" check issue.

Regards,
Jan Kratochvil

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https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=146810

Bug is still present in 2006-06-21 GDB CVS. The segfault is just a consequence of earlier failure to properly load the custom shared library:
Error while mapping shared library sections:
libc++test4dl.so: Success.

Index: solib.c
===================================================================
RCS file: /cvs/src/src/gdb/solib.c,v
retrieving revision 1.84
diff -u -p -r1.84 solib.c
--- solib.c 25 Feb 2006 04:36:39 -0000 1.84
+++ solib.c 22 Jun 2006 11:24:40 -0000
@@ -146,13 +146,17 @@ solib_open (char *in_pathname, char **fo
int found_file = -1;
char *temp_pathname = NULL;
char *p = in_pathname;
+ int solib_absolute_prefix_is_empty;
+
+ solib_absolute_prefix_is_empty = (!solib_absolute_prefix
+ || !*solib_absolute_prefix);

while (*p && !IS_DIR_SEPARATOR (*p))
p++;

if (*p)
{
- if (! IS_ABSOLUTE_PATH (in_pathname) || solib_absolute_prefix == NULL)
+ if (! IS_ABSOLUTE_PATH (in_pathname) || solib_absolute_prefix_is_empty)
temp_pathname = in_pathname;
else
{
@@ -208,14 +212,14 @@ solib_open (char *in_pathname, char **fo
&temp_pathname);

/* If not found, next search the inferior's $PATH environment variable. */
- if (found_file < 0 && solib_absolute_prefix == NULL)
+ if (found_file < 0 && solib_absolute_prefix_is_empty)
found_file = openp (get_in_environ (inferior_environ, "PATH"),
OPF_TRY_CWD_FIRST, in_pathname, O_RDONLY | O_BINARY, 0,
&temp_pathname);

/* If not found, next search the inferior's $LD_LIBRARY_PATH
environment variable. */
- if (found_file < 0 && solib_absolute_prefix == NULL)
+ if (found_file < 0 && solib_absolute_prefix_is_empty)
found_file = openp (get_in_environ (inferior_environ, "LD_LIBRARY_PATH"),
OPF_TRY_CWD_FIRST, in_pathname, O_RDONLY | O_BINARY, 0,
&temp_pathname);