Messages in this thread Patch in this message | | | Date | Fri, 12 Jan 2024 15:06:16 +0300 | From | "" <> | Subject | Re: [PATCH repost] x86/boot: Add a message about ignored early NMIs |
| |
On Fri, Jan 12, 2024 at 11:13:53AM +0000, NOMURA JUNICHI(野村 淳一) wrote: > Commit 78a509fba9c9 ("x86/boot: Ignore NMIs during very early boot") added > empty handler in early boot stage to avoid boot failure by spurious NMIs. > > Add a diagnostic message in case we need to know whether early NMIs have > occurred and/or what happened to them. > > Signed-off-by: Jun'ichi Nomura <junichi.nomura@nec.com> > Suggested-by: Borislav Petkov <bp@alien8.de> > Suggested-by: H. Peter Anvin <hpa@zytor.com> > Link: https://lore.kernel.org/lkml/20231130103339.GCZWhlA196uRklTMNF@fat_crate.local/ > > diff --git a/arch/x86/boot/compressed/ident_map_64.c b/arch/x86/boot/compressed/ident_map_64.c > --- a/arch/x86/boot/compressed/ident_map_64.c > +++ b/arch/x86/boot/compressed/ident_map_64.c > @@ -387,7 +387,10 @@ void do_boot_page_fault(struct pt_regs *regs, unsigned long error_code) > kernel_add_identity_map(address, end); > } > > +extern int spurious_nmi_count; > +
It has to be in a header file.
> void do_boot_nmi_trap(struct pt_regs *regs, unsigned long error_code) > { > /* Empty handler to ignore NMI during early boot */ > + spurious_nmi_count++; > } > diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c > --- a/arch/x86/boot/compressed/misc.c > +++ b/arch/x86/boot/compressed/misc.c > @@ -357,6 +357,8 @@ unsigned long decompress_kernel(unsigned char *outbuf, unsigned long virt_addr, > return entry; > } > > +int spurious_nmi_count; > +
It is not a right place to define a variable. Do it next to rest of variables at the beginning of the file. > /* > * The compressed kernel image (ZO), has been moved so that its position > * is against the end of the buffer used to hold the uncompressed kernel > @@ -493,6 +495,12 @@ asmlinkage __visible void *extract_kernel(void *rmode, unsigned char *output) > /* Disable exception handling before booting the kernel */ > cleanup_exception_handling(); > > + if (spurious_nmi_count) { > + error_putstr("Spurious early NMI ignored. Number of NMIs: 0x"); > + error_puthex(spurious_nmi_count); > + error_putstr("\n"); > + } > + > return output + entry_offset; > } >
-- Kiryl Shutsemau / Kirill A. Shutemov
| |