| commit | 50b6ad55b04d741eaa6121deed6876ff4fc28bc8 | [log] [tgz] |
|---|---|---|
| author | Mathias Krause <minipli@grsecurity.net> | Tue Jan 31 19:56:11 2023 +0100 |
| committer | Junio C Hamano <gitster@pobox.com> | Tue Jan 31 11:39:02 2023 -0800 |
| tree | 841ae5b8aeef7f0a3736a88dadfd2c004d725060 | |
| parent | c48035d29b4e524aed3a32f0403676f0d9128863 [diff] |
grep: fall back to interpreter if JIT memory allocation fails Under Linux systems with SELinux's 'deny_execmem' or PaX's MPROTECT enabled, the allocation of PCRE2's JIT rwx memory may be prohibited, making pcre2_jit_compile() fail with PCRE2_ERROR_NOMEMORY (-48): [user@fedora git]$ git grep -c PCRE2_JIT grep.c:1 [user@fedora git]$ # Enable SELinux's W^X policy [user@fedora git]$ sudo semanage boolean -m -1 deny_execmem [user@fedora git]$ # JIT memory allocation fails, breaking 'git grep' [user@fedora git]$ git grep -c PCRE2_JIT fatal: Couldn't JIT the PCRE2 pattern 'PCRE2_JIT', got '-48' Instead of failing hard in this case and making 'git grep' unusable on such systems, simply fall back to interpreter mode, leading to a much better user experience. As having a functional PCRE2 JIT compiler is a legitimate use case for performance reasons, we'll only do the fallback if the supposedly available JIT is found to be non-functional by attempting to JIT compile a very simple pattern. If this fails, JIT is deemed to be non-functional and we do the interpreter fallback. For all other cases, i.e. the simple pattern can be compiled but the user provided cannot, we fail hard as we do now as the reason for the failure must be the pattern itself. To aid users in helping themselves change the error message to include a hint about the '(*NO_JIT)' prefix. Also clip the pattern at 64 characters to ensure the hint will be seen by the user and not internally truncated by the die() function. Cc: Carlo Marcelo Arenas Belón <carenas@gmail.com> Signed-off-by: Mathias Krause <minipli@grsecurity.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
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