Re: [Crash-utility] [PATCH] Fix C99 compatibility issues in embedded copy of GDB
* HAGIO KAZUHITO(萩尾 一仁):
> +@@ -123,14 +142,70 @@
> + #define __bos(ptr) __builtin_object_size (ptr, __USE_FORTIFY_LEVEL > 1)
> + #define __bos0(ptr) __builtin_object_size (ptr, 0)
> +
> ++/* Use __builtin_dynamic_object_size at _FORTIFY_SOURCE=3 when available. */
> ++#if __USE_FORTIFY_LEVEL == 3 && (__glibc_clang_prereq (9, 0) \
> ++ || __GNUC_PREREQ (12, 0))
> ++# define __glibc_objsize0(__o) __builtin_dynamic_object_size (__o, 0)
> ++# define __glibc_objsize(__o) __builtin_dynamic_object_size (__o, 1)
> ++#else
> ++# define __glibc_objsize0(__o) __bos0 (__o)
> ++# define __glibc_objsize(__o) __bos (__o)
> ++#endif
> ++
> ++#if __USE_FORTIFY_LEVEL > 0
I could not find this line in the latest GDB source and the related
patches. What is this for?
We need to sync this again with gnulib/GDB. It was added here, in
glibc, which is the primary source of this file:
commit 2337e04e21ba6040926ec871e403533f77043c40
Author: Siddhesh Poyarekar <siddhesh(a)sourceware.org>
Date: Thu Feb 2 07:49:02 2023 -0500
cdefs: Limit definition of fortification macros
Define the __glibc_fortify and other macros only when __FORTIFY_LEVEL >
0. This has the effect of not defining these macros on older C90
compilers that do not have support for variable length argument lists.
Also trim off the trailing backslashes from the definition of
__glibc_fortify and __glibc_fortify_n macros.
Signed-off-by: Siddhesh Poyarekar <siddhesh(a)sourceware.org>
Reviewed-by: Florian Weimer <fweimer(a)redhat.com>
I should have made a note that this is coming from the ultimate upstream
sources.
I raised the issue of <sys/cdefs.h> syncing here:
Updating <sys/cdefs.h> in glibc and gnulib
<https://sourceware.org/pipermail/libc-alpha/2023-February/145758.html>
> +@@ -134,6 +136,7 @@ typedef int (*_bashfunc)(const char *,
...);
> + #else
> + typedef int (*_bashfunc)();
> + #endif
> ++#include <stdlib.h>
> + main()
The GDB patch b4f26d541aa7 ("Import GNU Readline 8.1") has the
following:
@@ -134,6 +138,8 @@ typedef int (*_bashfunc)(const char *, ...);
#else
typedef int (*_bashfunc)();
#endif
+#include <stdlib.h>
+int
main()
{
_bashfunc pf;
Isn't this "int" needed?
It is, but this part is not actually used (the file is more of a macro
library for bash, I guess, and the use in readline is merely an
afterthought).
The problem is that the upstream patch does not really apply to the GDB
10.2 sources. None of this work is really forward-looking, given that
crash will eventually have to import a newer GDB version.
Another option would be to build crash against system readline, like the
Fedora gdb package does it.
Thanks,
Florian