Florian Weimer

Florian Weimer's contributions

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Article

Why glibc 2.34 removed libpthread

Florian Weimer

Consolidation of libraries in the GNU C library means more error-free builds, but there are consequences for developers and system administrators.

GNU C library
Article

Recommended compiler and linker flags for GCC

Florian Weimer

This article walks through a list of recommended build flags for when you compile your C or C++ programs with GCC. Do you know which build flags you need to specify in order to obtain the same level of security hardening that GNU/Linux distributions such as Fedora and Red Hat Enterprise Linux use?

GNU C library
Article

Adding buffer overflow detection to string functions

Florian Weimer

This article describes the steps required to add buffer overflow protection to string functions. As a real-world example, we use the strlcpy function, which is implemented in the libbsd library on some GNU/Linux systems. This kind of buffer overflow protection uses a GNU Compiler Collection (GCC) feature for array size tracking (“source fortification”), accessed through the __builtin_object_size GCC built-in function. In general, these checks are added in a size-checking wrapper function around the original (wrapped) function, which is strlcpy in...

GNU C library
Article

Upgrading the GNU C Library within Red Hat Enterprise Linux

Florian Weimer

Occasionally, there's a need for a new GNU C Library for a given application to run. For example, some versions of the Google Chrome browser started to warn users on Red Hat Enterprise Linux 7 that future versions of Chrome would not support their operating system. The Chromium source code contained a version check, flagging all versions of the GNU C Library (glibc) older than 2.19 as obsolete. This check has since been relaxed to 2.17 (the version in Red...