Re: [PATCH v2] x86/boot: Add a message about ignored early NMIs

[H. Peter Anvin]

On 1/24/24 03:44, NOMURA JUNICHI(野村 淳一) wrote:
> > From: Borislav Petkov <bp@xxxxxxxxx>
> > On Mon, Jan 15, 2024 at 08:57:45AM +0000, NOMURA JUNICHI(野村 淳一) wrote:
> > > +	if (spurious_nmi_count) {
> > > +		error_putstr("Spurious early NMI ignored. Number of NMIs: 0x");
> > > +		error_puthex(spurious_nmi_count);
> > > +		error_putstr("\n");
> >
> > Uff, that's just silly:
> >
> > Spurious early NMIs ignored: 0x0000000000000017
> >
> > Would you like to add a error_putnum() or so in a prepatch which would
> > make this output
> >
> > Spurious early NMIs ignored: 23.
> >
> > ?
> >
> > So that it is human readable and doesn't make me wonder what that hex
> > value is supposed to mean?
>
> Yes, it would be nicer to print that way.  I used the existing error_puthex() just
> to keep the patch minimal.  I will try to add error_putnum().
>
> > Btw, please use this version when sending next time:

Here is a *completely* untested patch for you...

	-hpa
diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
index b99e08e6815b..bf2aac4f195e 100644
--- a/arch/x86/boot/compressed/misc.c
+++ b/arch/x86/boot/compressed/misc.c
@@ -164,21 +164,34 @@ void __putstr(const char *s)
 	outb(0xff & (pos >> 1), vidport+1);
 }
 
-void __puthex(unsigned long value)
+static noinline void __putnum(unsigned long value, unsigned int base,
+			      int mindig)
 {
-	char alpha[2] = "0";
-	int bits;
+	char buf[8*sizeof(value)+1];
+	char *p;
 
-	for (bits = sizeof(value) * 8 - 4; bits >= 0; bits -= 4) {
-		unsigned long digit = (value >> bits) & 0xf;
+	p = buf + sizeof(buf);
+	*--p = '\0';
 
-		if (digit < 0xA)
-			alpha[0] = '0' + digit;
-		else
-			alpha[0] = 'a' + (digit - 0xA);
+	while (mindig-- > 0 || value) {
+		unsigned char digit = value % base;
+		digit += (digit >= 10) ? ('a'-10) : '0';
+		*--p = digit;
 
-		__putstr(alpha);
+		value /= base;
 	}
+
+	__putstr(p);
+}
+
+void __puthex(unsigned long value)
+{
+	__putnum(value, 16, sizeof(value)*2);
+}
+
+void __putdec(unsigned long value)
+{
+	__putnum(value, 10, 1);
 }
 
 #ifdef CONFIG_X86_NEED_RELOCS
diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h
index bc2f0f17fb90..6502bc69d1b8 100644
--- a/arch/x86/boot/compressed/misc.h
+++ b/arch/x86/boot/compressed/misc.h
@@ -63,8 +63,10 @@ void *malloc(int size);
 void free(void *where);
 void __putstr(const char *s);
 void __puthex(unsigned long value);
+void __putdec(unsigned long value);
 #define error_putstr(__x)  __putstr(__x)
 #define error_puthex(__x)  __puthex(__x)
+#define error_putdec(__x)  __putdec(__x)
 
 #ifdef CONFIG_X86_VERBOSE_BOOTUP