[RFC,0/5] tools/nolibc: add support for stack protector

Message

Thomas Weißschuh March 7, 2023, 10:22 p.m. UTC

Stack protection is a feature to detect and handle stack buffer
overflows at runtime.
For this to work the compiler and libc have to collaborate.

This patch adds the following parts to nolibc that are required by the
compiler:

* __stack_chk_guard: random sentinel value
* __stack_chk_fail: handler for detected stack smashes

In addition an initialization function is added that randomizes the
sentinel value.

Only support for global guards is implemented.
Register guards are useful in multi-threaded context which nolibc does
not provide support for.

Link: https://lwn.net/Articles/584225/

Signed-off-by: Thomas Weißschuh <[e-mail]>
---
Thomas Weißschuh (5):
      tools/nolibc: add definitions for standard fds
      tools/nolibc: add helpers for wait() signal exits
      tools/nolibc: tests: constify test_names
      tools/nolibc: add support for stack protector
      tools/nolibc: tests: add test for -fstack-protector

 tools/include/nolibc/Makefile                |  4 +-
 tools/include/nolibc/arch-i386.h             |  8 ++-
 tools/include/nolibc/arch-x86_64.h           |  5 ++
 tools/include/nolibc/nolibc.h                |  1 +
 tools/include/nolibc/stackprotector.h        | 48 ++++++++++++++++++
 tools/include/nolibc/types.h                 |  2 +
 tools/include/nolibc/unistd.h                |  5 ++
 tools/testing/selftests/nolibc/Makefile      | 12 +++++
 tools/testing/selftests/nolibc/nolibc-test.c | 76 ++++++++++++++++++++++++++--
 9 files changed, 155 insertions(+), 6 deletions(-)
---
base-commit: b7453ccfdbe0b9e95b488814c53e8cbf8966aae4
change-id: 20230223-nolibc-stackprotector-d4d5f48ff771

Best regards,