From: Nick Desaulniers <ndesaulniers@google.com>
To: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de
Cc: peterz@infradead.org, clang-built-linux@googlegroups.com,
linux-kernel@vger.kernel.org, yamada.masahiro@socionext.com,
Nick Desaulniers <ndesaulniers@google.com>
Subject: [PATCH v3 0/2] Support kexec/kdump for clang built kernel
Date: Tue, 23 Jul 2019 14:24:12 -0700 [thread overview]
Message-ID: <20190723212418.36379-3-ndesaulniers@google.com> (raw)
In-Reply-To: <20190723212418.36379-1-ndesaulniers@google.com>
1. Reuse the implementation of memcpy and memset instead of relying on
__builtin_memcpy and __builtin_memset as it causes infinite recursion
in Clang (at any opt level) or GCC at -O2.
2. Don't reset KBUILD_CFLAGS, rather filter CONFIG_FUNCTION_TRACER,
CONFIG_STACKPROTECTOR, and CONFIG_STACKPROTECTOR_STRONG flags via
`CFLAGS_REMOVE_<file>.o'
A good test of this series (besides boot testing a kexec kernel):
* There should be no undefined symbols in arch/x86/purgatory/purgatory.ro:
$ nm arch/x86/purgatory/purgatory.ro
particularly `warn`, `bcmp`, `__stack_chk_fail`, `memcpy` or `memset`.
* `-pg`, `-fstack-protector`, `-fstack-protector-strong` should not be
added to the command line for the c source files under arch/x86/purgatory/
when compiling with CONFIG_FUNCTION_TRACER=y, CONFIG_STACKPROTECTOR=y,
and CONFIG_STACKPROTECTOR_STRONG=y.
V3 of: https://groups.google.com/forum/#!msg/clang-built-linux/GzThkAkZqqI/J727I6vpBwAJ
Nick Desaulniers (2):
x86/purgatory: do not use __builtin_memcpy and __builtin_memset
x86/purgatory: use CFLAGS_REMOVE rather than reset KBUILD_CFLAGS
arch/x86/boot/string.c | 7 +++++++
arch/x86/purgatory/Makefile | 29 ++++++++++++++++++++++++-----
arch/x86/purgatory/purgatory.c | 6 ++++++
arch/x86/purgatory/string.c | 23 -----------------------
4 files changed, 37 insertions(+), 28 deletions(-)
delete mode 100644 arch/x86/purgatory/string.c
--
2.22.0.709.g102302147b-goog
next prev parent reply other threads:[~2019-07-23 21:24 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-23 21:24 [PATCH v3 1/2] x86/purgatory: do not use __builtin_memcpy and __builtin_memset Nick Desaulniers
2019-07-23 21:24 ` [PATCH v3 2/2] x86/purgatory: use CFLAGS_REMOVE rather than reset KBUILD_CFLAGS Nick Desaulniers
2019-07-24 10:35 ` Thomas Gleixner
2019-07-24 23:49 ` Vaibhav Rustagi
2019-07-23 21:24 ` Nick Desaulniers [this message]
2019-07-24 10:33 ` [PATCH v3 1/2] x86/purgatory: do not use __builtin_memcpy and __builtin_memset Thomas Gleixner
2019-07-24 20:55 ` Vaibhav Rustagi
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190723212418.36379-3-ndesaulniers@google.com \
--to=ndesaulniers@google.com \
--cc=bp@alien8.de \
--cc=clang-built-linux@googlegroups.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--cc=yamada.masahiro@socionext.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.