tree 04722da34460af3eb1c2785682f62a3658453b07
parent be28dd623f0d6eb3a97ebc428f8cdc7f6bf4e8f4
author David Benjamin <davidben@google.com> 1588976887 -0400
committer CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org> 1589477602 +0000

Still query getauxval if reading /proc/cpuinfo fails.

If BoringSSL is used in a sandbox without /proc/cpuinfo, we will
silently act as if the CPU is missing capabilities, even though
getauxval may be available. We use /proc/cpuinfo to work around a
missing AT_HWCAP2 and ignore a particular broken CPU.

Ignoring the former fails closed, so it's safe to proceed. The latter
fails closed, but it is now vanishingly rare (even missing AT_HWCAP2 has
largely dropped off), so instead proceed with getauxval. This makes the
/proc paths largely optional.

Change-Id: Ib198c4f78ccdae874d55669b6a7508dfbeac0f44
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/41325
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>