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authorNOMURA JUNICHI(野村 淳一) <junichi.nomura@nec.com>2024-02-02 03:51:58 +0000
committerBorislav Petkov (AMD) <bp@alien8.de>2024-02-06 10:51:11 +0100
commitac456ca0af4fe9630cf84e7efd20b7f7bf596aab (patch)
treeeb5157d638000904ed39208de9197e1cf61d3287 /arch/x86/boot
parent9ba8ec8ee67a00eb5631364e4b716f35559724d4 (diff)
x86/boot: Add a message about ignored early NMIs
Commit 78a509fba9c9 ("x86/boot: Ignore NMIs during very early boot") added an empty handler in early boot stage to avoid boot failure due to spurious NMIs. Add a diagnostic message to show that early NMIs have occurred. [ bp: Touchups. ] [ Committer note: tested by stopping the guest really early and injecting NMIs through qemu's monitor. Result: early console in setup code Spurious early NMIs ignored: 13 ... ] Suggested-by: Borislav Petkov <bp@alien8.de> Suggested-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Jun'ichi Nomura <junichi.nomura@nec.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Link: https://lore.kernel.org/lkml/20231130103339.GCZWhlA196uRklTMNF@fat_crate.local
Diffstat (limited to 'arch/x86/boot')
-rw-r--r--arch/x86/boot/compressed/ident_map_64.c2
-rw-r--r--arch/x86/boot/compressed/misc.c7
-rw-r--r--arch/x86/boot/compressed/misc.h1
3 files changed, 9 insertions, 1 deletions
diff --git a/arch/x86/boot/compressed/ident_map_64.c b/arch/x86/boot/compressed/ident_map_64.c
index d040080d7edb..4a029baa5147 100644
--- a/arch/x86/boot/compressed/ident_map_64.c
+++ b/arch/x86/boot/compressed/ident_map_64.c
@@ -389,5 +389,5 @@ void do_boot_page_fault(struct pt_regs *regs, unsigned long error_code)
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
index bf2aac4f195e..bd6857a9f15a 100644
--- a/arch/x86/boot/compressed/misc.c
+++ b/arch/x86/boot/compressed/misc.c
@@ -52,6 +52,7 @@ struct port_io_ops pio_ops;
memptr free_mem_ptr;
memptr free_mem_end_ptr;
+int spurious_nmi_count;
static char *vidmem;
static int vidport;
@@ -506,6 +507,12 @@ 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 NMIs ignored: ");
+ error_putdec(spurious_nmi_count);
+ error_putstr("\n");
+ }
+
return output + entry_offset;
}
diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h
index 6502bc69d1b8..b353a7be380c 100644
--- a/arch/x86/boot/compressed/misc.h
+++ b/arch/x86/boot/compressed/misc.h
@@ -59,6 +59,7 @@ extern char _head[], _end[];
/* misc.c */
extern memptr free_mem_ptr;
extern memptr free_mem_end_ptr;
+extern int spurious_nmi_count;
void *malloc(int size);
void free(void *where);
void __putstr(const char *s);