The following commit has been merged into the x86/urgent branch of tip:
Commit-ID: 2ae30fa4ee58535d122f79c6860fbbab87b20b06
Gitweb: https://git.kernel.org/tip/2ae30fa4ee58535d122f79c6860fbbab87b20b06
Author: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
AuthorDate: Fri, 14 Mar 2025 17:48:18 +09:00
Committer: Ingo Molnar <mingo@kernel.org>
CommitterDate: Wed, 19 Mar 2025 21:47:11 +01:00
x86/pkeys: Add quirk to disable PKU when XFEATURE_PKRU is missing
Even when X86_FEATURE_PKU and X86_FEATURE_OSPKE are available,
XFEATURE_PKRU can be missing on some popular VM environments
such as Apple Virtualization.
In such a case, pkeys has to be disabled to avoid a boot time hang:
WARNING: CPU: 0 PID: 1 at arch/x86/kernel/fpu/xstate.c:1003 get_xsave_addr_user+0x28/0x40
(...)
Call Trace:
<TASK>
? get_xsave_addr_user+0x28/0x40
? __warn.cold+0x8e/0xea
? get_xsave_addr_user+0x28/0x40
? report_bug+0xff/0x140
? handle_bug+0x3b/0x70
? exc_invalid_op+0x17/0x70
? asm_exc_invalid_op+0x1a/0x20
? get_xsave_addr_user+0x28/0x40
copy_fpstate_to_sigframe+0x1be/0x380
? __put_user_8+0x11/0x20
get_sigframe+0xf1/0x280
x64_setup_rt_frame+0x67/0x2c0
arch_do_signal_or_restart+0x1b3/0x240
syscall_exit_to_user_mode+0xb0/0x130
do_syscall_64+0xab/0x1a0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Tested with MacOS 13.5.2 running on MacBook Pro 2020 with
Intel(R) Core(TM) i7-1068NG7 CPU @ 2.30GHz.
Fixes: 70044df250d0 ("x86/pkeys: Update PKRU to enable all pkeys before XSAVE")
Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250314084818.2826-1-akihiro.suda.cz@hco.ntt.co.jp
---
arch/x86/kernel/cpu/common.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 7cce91b..5def904 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -517,7 +517,8 @@ static bool pku_disabled;
static __always_inline void setup_pku(struct cpuinfo_x86 *c)
{
if (c == &boot_cpu_data) {
- if (pku_disabled || !cpu_feature_enabled(X86_FEATURE_PKU))
+ if (pku_disabled || !cpu_feature_enabled(X86_FEATURE_PKU) ||
+ !cpu_has_xfeatures(XFEATURE_PKRU, NULL))
return;
/*
* Setting CR4.PKE will cause the X86_FEATURE_OSPKE cpuid