https://github.com/torvalds/linux
Revision 571c30b1a88465a1c85a6f7762609939b9085a15 authored by Thadeu Lima de Souza Cascardo on 28 July 2022, 12:26:02 UTC, committed by Borislav Petkov on 29 July 2022, 08:02:35 UTC
Some cloud hypervisors do not provide IBPB on very recent CPU processors, including AMD processors affected by Retbleed. Using IBPB before firmware calls on such systems would cause a GPF at boot like the one below. Do not enable such calls when IBPB support is not present. EFI Variables Facility v0.08 2004-May-17 general protection fault, maybe for address 0x1: 0000 [#1] PREEMPT SMP NOPTI CPU: 0 PID: 24 Comm: kworker/u2:1 Not tainted 5.19.0-rc8+ #7 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 Workqueue: efi_rts_wq efi_call_rts RIP: 0010:efi_call_rts Code: e8 37 33 58 ff 41 bf 48 00 00 00 49 89 c0 44 89 f9 48 83 c8 01 4c 89 c2 48 c1 ea 20 66 90 b9 49 00 00 00 b8 01 00 00 00 31 d2 <0f> 30 e8 7b 9f 5d ff e8 f6 f8 ff ff 4c 89 f1 4c 89 ea 4c 89 e6 48 RSP: 0018:ffffb373800d7e38 EFLAGS: 00010246 RAX: 0000000000000001 RBX: 0000000000000006 RCX: 0000000000000049 RDX: 0000000000000000 RSI: ffff94fbc19d8fe0 RDI: ffff94fbc1b2b300 RBP: ffffb373800d7e70 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000000b R11: 000000000000000b R12: ffffb3738001fd78 R13: ffff94fbc2fcfc00 R14: ffffb3738001fd80 R15: 0000000000000048 FS: 0000000000000000(0000) GS:ffff94fc3da00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff94fc30201000 CR3: 000000006f610000 CR4: 00000000000406f0 Call Trace: <TASK> ? __wake_up process_one_work worker_thread ? rescuer_thread kthread ? kthread_complete_and_exit ret_from_fork </TASK> Modules linked in: Fixes: 28a99e95f55c ("x86/amd: Use IBPB for firmware calls") Reported-by: Dimitri John Ledkov <dimitri.ledkov@canonical.com> Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20220728122602.2500509-1-cascardo@canonical.com
1 parent 5bb6c1d
Tip revision: 571c30b1a88465a1c85a6f7762609939b9085a15 authored by Thadeu Lima de Souza Cascardo on 28 July 2022, 12:26:02 UTC
x86/bugs: Do not enable IBPB at firmware entry when IBPB is not available
x86/bugs: Do not enable IBPB at firmware entry when IBPB is not available
Tip revision: 571c30b
File | Mode | Size |
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LICENSES | ||
arch | ||
block | ||
certs | ||
crypto | ||
drivers | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.clang-format | -rw-r--r-- | 19.8 KB |
.cocciconfig | -rw-r--r-- | 59 bytes |
.get_maintainer.ignore | -rw-r--r-- | 71 bytes |
.gitattributes | -rw-r--r-- | 62 bytes |
.gitignore | -rw-r--r-- | 1.9 KB |
.mailmap | -rw-r--r-- | 23.0 KB |
COPYING | -rw-r--r-- | 496 bytes |
CREDITS | -rw-r--r-- | 99.0 KB |
Kbuild | -rw-r--r-- | 1.3 KB |
Kconfig | -rw-r--r-- | 555 bytes |
MAINTAINERS | -rw-r--r-- | 653.4 KB |
Makefile | -rw-r--r-- | 64.1 KB |
README | -rw-r--r-- | 727 bytes |
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