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| author | Steven Noonan <steven@uplinklabs.net> | 2014-03-28 17:19:02 +0100 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2014-03-31 20:16:02 +0100 |
| commit | 63678e17cf399ff81b93417fe7bee8d6ef6b6b1b (patch) | |
| tree | 85c035792e228efd51594b60d7c6f345adf1b9a8 /qemu-img.c | |
| parent | 58b590148ca1b19f64f533d40e32b5acce5c21e7 (diff) | |
| download | qemu-63678e17cf399ff81b93417fe7bee8d6ef6b6b1b.tar.gz | |
configure: add option to disable -fstack-protector flags
The -fstack-protector flag family is useful for ensuring safety and for
debugging, but has a performance impact. Here are some boot time comparisons of
the various versions of -fstack-protector using qemu-system-arm on an x86_64
host:
# -fstack-protector-all
Startup finished in 1.810s (kernel) + 12.331s (initrd) + 49.016s (userspace) = 1min 3.159s
Startup finished in 1.801s (kernel) + 12.287s (initrd) + 47.925s (userspace) = 1min 2.013s
Startup finished in 1.812s (kernel) + 12.302s (initrd) + 47.995s (userspace) = 1min 2.111s
# -fstack-protector-strong
Startup finished in 1.744s (kernel) + 11.223s (initrd) + 44.688s (userspace) = 57.657s
Startup finished in 1.721s (kernel) + 11.222s (initrd) + 44.194s (userspace) = 57.138s
Startup finished in 1.693s (kernel) + 11.250s (initrd) + 44.426s (userspace) = 57.370s
# -fstack-protector
Startup finished in 1.705s (kernel) + 11.409s (initrd) + 43.563s (userspace) = 56.677s
Startup finished in 1.877s (kernel) + 11.137s (initrd) + 43.719s (userspace) = 56.734s
Startup finished in 1.708s (kernel) + 11.141s (initrd) + 43.628s (userspace) = 56.478s
# no stack protector
Startup finished in 1.743s (kernel) + 11.190s (initrd) + 43.709s (userspace) = 56.643s
Startup finished in 1.763s (kernel) + 11.216s (initrd) + 43.767s (userspace) = 56.747s
Startup finished in 1.711s (kernel) + 11.283s (initrd) + 43.878s (userspace) = 56.873s
This patch introduces a configure option to disable the stack protector
entirely, and conditional stack protector flag selection (in order,
based on availability): -fstack-protector-strong, -fstack-protector-all,
no stack protector.
Signed-off-by: Steven Noonan <snoonan@amazon.com>
Cc: Anthony Liguori <aliguori@amazon.com>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
[Prefer -fstack-protector-all to -fstack-protector, suggested by
Laurent Desnogues. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'qemu-img.c')
0 files changed, 0 insertions, 0 deletions