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| author | Andrew Cooper <andrew.cooper3@citrix.com> | 2024-12-22 00:10:46 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-02-21 15:50:09 +0300 |
| commit | e43e2461abea301f117feab786be0259c2d6e090 (patch) | |
| tree | 841d9247d159961afeaaae91a4d73edf99466bac | |
| parent | 8255da6dd443f8679626a71d7aba1d0500c54a6f (diff) | |
| download | linux-e43e2461abea301f117feab786be0259c2d6e090.tar.xz | |
x86/static-call: Remove early_boot_irqs_disabled check to fix Xen PVH dom0
commit 5cc2db37124bb33914996d6fdbb2ddb3811f2945 upstream.
__static_call_update_early() has a check for early_boot_irqs_disabled, but
is used before early_boot_irqs_disabled is set up in start_kernel().
Xen PV has always special cased early_boot_irqs_disabled, but Xen PVH does
not and falls over the BUG when booting as dom0.
It is very suspect that early_boot_irqs_disabled starts as 0, becomes 1 for
a time, then becomes 0 again, but as this needs backporting to fix a
breakage in a security fix, dropping the BUG_ON() is the far safer option.
Fixes: 0ef8047b737d ("x86/static-call: provide a way to do very early static-call updates")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219620
Reported-by: Alex Zenla <alex@edera.dev>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Alex Zenla <alex@edera.dev>
Link: https://lore.kernel.org/r/20241221211046.6475-1-andrew.cooper3@citrix.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/x86/kernel/static_call.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/arch/x86/kernel/static_call.c b/arch/x86/kernel/static_call.c index 587975eca728..ca8dfc0c9edb 100644 --- a/arch/x86/kernel/static_call.c +++ b/arch/x86/kernel/static_call.c @@ -173,7 +173,6 @@ EXPORT_SYMBOL_GPL(arch_static_call_transform); noinstr void __static_call_update_early(void *tramp, void *func) { BUG_ON(system_state != SYSTEM_BOOTING); - BUG_ON(!early_boot_irqs_disabled); BUG_ON(static_call_initialized); __text_gen_insn(tramp, JMP32_INSN_OPCODE, tramp, func, JMP32_INSN_SIZE); sync_core(); |