x86: Fix early boot crash on gcc-10
Fix a boot failure where the kernel is built with gcc-10 with stack
protector enabled by default:
Kernel panic — not syncing: stack-protector: Kernel stack is corrupted in: start_secondary
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.6.0-rc5—00235—gfffb08b37df9 #139
Hardware name: Gigabyte Technology Co., Ltd. To be filled by O.E.M./H77M—D3H, BIOS F12 11/14/2013
Call Trace:
dump_stack
panic
? start_secondary
__stack_chk_fail
start_secondary
secondary_startup_64
-—-[ end Kernel panic — not syncing: stack—protector: Kernel stack is corrupted in: start_secondary
This happens because start_secondary() is responsible for setting
up initial stack canary value in smpboot.c but nothing prevents gcc
from inserting stack canary into start_secondary() itself before the
boot_init_stack_canary() call which sets up said canary value.
Inhibit the stack canary addition for start_secondary() only.
[ bp: Massage a bit. ]
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: Michael Matz <matz@suse.de>
Link: https://lkml.kernel.org/r/20200328084858.421444-1-slyfox@gentoo.org
3 files changed
