path: root/tools/testing/selftests/size/get_size.c (follow)
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2020-01-16kselftest: Minimise dependency of get_size on C library interfacesSiddhesh Poyarekar1-6/+18
It was observed[1] on arm64 that __builtin_strlen led to an infinite loop in the get_size selftest. This is because __builtin_strlen (and other builtins) may sometimes result in a call to the C library function. The C library implementation of strlen uses an IFUNC resolver to load the most efficient strlen implementation for the underlying machine and hence has a PLT indirection even for static binaries. Because this binary avoids the C library startup routines, the PLT initialization never happens and hence the program gets stuck in an infinite loop. On x86_64 the __builtin_strlen just happens to expand inline and avoid the call but that is not always guaranteed. Further, while testing on x86_64 (Fedora 31), it was observed that the test also failed with a segfault inside write() because the generated code for the write function in glibc seems to access TLS before the syscall (probably due to the cancellation point check) and fails because TLS is not initialised. To mitigate these problems, this patch reduces the interface with the C library to just the syscall function. The syscall function still sets errno on failure, which is undesirable but for now it only affects cases where syscalls fail. [1] https://bugs.linaro.org/show_bug.cgi?id=5479 Signed-off-by: Siddhesh Poyarekar <siddhesh@gotplt.org> Reported-by: Masami Hiramatsu <masami.hiramatsu@linaro.org> Tested-by: Masami Hiramatsu <masami.hiramatsu@linaro.org> Reviewed-by: Tim Bird <tim.bird@sony.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 166Thomas Gleixner1-2/+1
Based on 1 normalized pattern(s): licensed under the terms of the gnu gpl license version 2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 62 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.929121379@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-14kselftest: convert get_size to use stricter TAP13 formatTim Bird1-11/+16
1. Add the TAP13 header 2. remove variable data from the test description line 3. move the plan count to the end of the file, for consistency with other kselftests 4. convert memory data from diagnostic (comment) format, to a YAML block Signed-off-by: Tim Bird <tim.bird@sony.com> Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
2014-12-03selftest: size: Add size test for Linux kernelTim Bird1-0/+100
This test shows the amount of memory used by the system. Note that this is dependent on the user-space that is loaded when this program runs. Optimally, this program would be run as the init program itself. The program is optimized for size itself, to avoid conflating its own execution with that of the system software. The code is compiled statically, with no stdlibs. On my x86_64 system, this results in a statically linked binary of less than 5K. Signed-off-by: Tim Bird <tim.bird@sonymobile.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>