glibc/string/bits, branch master

string: Improve fortify with clang

2024-02-27T13:52:58Z

It improve fortify checks for strcpy, stpcpy, strncpy, stpncpy, strcat, strncat, strlcpy, and strlcat. The runtime and compile checks have similar coverage as with GCC. Checked on aarch64, armhf, x86_64, and i686. Reviewed-by: Carlos O'Donell Tested-by: Carlos O'Donell

Update copyright dates with scripts/update-copyrights

2024-01-01T18:53:40Z

Implement strlcpy and strlcat [BZ #178]

2023-06-14T16:10:08Z

These functions are about to be added to POSIX, under Austin Group issue 986. The fortified strlcat implementation does not raise SIGABRT if the destination buffer does not contain a null terminator, it just inherits the non-failing regular strlcat behavior. Reviewed-by: Siddhesh Poyarekar

Update copyright dates with scripts/update-copyrights

2023-01-06T21:14:39Z

string.h: fix __fortified_attr_access macro call [BZ #29162]

2022-05-23T08:26:43Z

commit e938c0274 "Don't add access size hints to fortifiable functions" converted a few '__attr_access ((...))' into '__fortified_attr_access (...)' calls. But one of conversions had double parentheses of '__fortified_attr_access (...)'. Noticed as a gnat6 build failure: /<>-glibc-2.34-210-dev/include/bits/string_fortified.h:110:50: error: macro "__fortified_attr_access" requires 3 arguments, but only 1 given The change fixes parentheses. This is seen when using compilers that do not support __builtin___stpncpy_chk, e.g. gcc older than 4.7, clang older than 2.6 or some compiler not derived from gcc or clang. Signed-off-by: Sergei Trofimovich Reviewed-by: Siddhesh Poyarekar

debug: Synchronize feature guards in fortified functions [BZ #28746]

2022-01-12T18:04:48Z

Some functions (e.g. stpcpy, pread64, etc.) had moved to POSIX in the main headers as they got incorporated into the standard, but their fortified variants remained under __USE_GNU. As a result, these functions did not get fortified when _GNU_SOURCE was not defined. Add test wrappers that check all functions tested in tst-chk0 at all levels with _GNU_SOURCE undefined and then use the failures to (1) exclude checks for _GNU_SOURCE functions in these tests and (2) Fix feature macro guards in the fortified function headers so that they're the same as the ones in the main headers. This fixes BZ #28746. Signed-off-by: Siddhesh Poyarekar Reviewed-by: Adhemerval Zanella

Update copyright dates with scripts/update-copyrights

2022-01-01T19:40:24Z

I used these shell commands: ../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright (cd ../glibc && git commit -am"[this commit message]") and then ignored the output, which consisted lines saying "FOO: warning: copyright statement not found" for each of 7061 files FOO. I then removed trailing white space from math/tgmath.h, support/tst-support-open-dev-null-range.c, and sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following obscure pre-commit check failure diagnostics from Savannah. I don't know why I run into these diagnostics whereas others evidently do not. remote: *** 912-#endif remote: *** 913: remote: *** 914- remote: *** error: lines with trailing whitespace found ... remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines

Don't add access size hints to fortifiable functions

2021-10-20T03:03:31Z

In the context of a function definition, the size hints imply that the size of an object pointed to by one parameter is another parameter. This doesn't make sense for the fortified versions of the functions since that's the bit it's trying to validate. This is harmless with __builtin_object_size since it has fairly simple semantics when it comes to objects passed as function parameters. With __builtin_dynamic_object_size we could (as my patchset for gcc[1] already does) use the access attribute to determine the object size in the general case but it misleads the fortified functions. Basically the problem occurs when access attributes are present on regular functions that have inline fortified definitions to generate _chk variants; the attributes get inherited by these definitions, causing problems when analyzing them. For example with poll(fds, nfds, timeout), nfds is hinted using the __attr_access as being the size of fds. Now, when analyzing the inline function definition in bits/poll2.h, the compiler sees that nfds is the size of fds and tries to use that information in the function body. In _FORTIFY_SOURCE=3 case, where the object size could be a non-constant expression, this information results in the conclusion that nfds is the size of fds, which defeats the purpose of the implementation because we're trying to check here if nfds does indeed represent the size of fds. Hence for this case, it is best to not have the access attribute. With the attributes gone, the expression evaluation should get delayed until the function is actually inlined into its destinations. Disable the access attribute for fortified function inline functions when building at _FORTIFY_SOURCE=3 to make this work better. The access attributes remain for the _chk variants since they can be used by the compiler to warn when the caller is passing invalid arguments. [1] https://gcc.gnu.org/pipermail/gcc-patches/2021-October/581125.html Signed-off-by: Siddhesh Poyarekar

Update copyright dates with scripts/update-copyrights

2021-01-02T20:17:34Z

I used these shell commands: ../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright (cd ../glibc && git commit -am"[this commit message]") and then ignored the output, which consisted lines saying "FOO: warning: copyright statement not found" for each of 6694 files FOO. I then removed trailing white space from benchtests/bench-pthread-locks.c and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this diagnostic from Savannah: remote: *** pre-commit check failed ... remote: *** error: lines with trailing whitespace found remote: error: hook declined to update refs/heads/master

string: Enable __FORTIFY_LEVEL=3

2020-12-31T11:25:21Z

This change enhances fortified string functions to use __builtin_dynamic_object_size under _FORTIFY_SOURCE=3 whenever the compiler supports it.