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powerpc/prom: Fix %u/%llx usage since prom_printf() change

PATCH Applied Mathieu Malaterre 2 participants 2 messages May 29, 2018 – Jun 1, 2018 PowerPC

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Mathieu Malaterre

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PATCH 1/1 powerpc/prom: Fix %u/%llx usage since prom_printf() change

In commit eae5f709a4d7 ("powerpc: Add __printf verification to prom_printf") __printf attribute was added to prom_printf(), which means GCC started warning about type/format mismatches. As part of that commit we changed some "%lx" formats to "%llx" where the type is actually unsigned long long.

Unfortunately prom_printf() doesn't know how to print "%llx", it just prints a literal "lx", eg:

reserved memory map:
lx - lx
lx - lx

prom_printf() also doesn't know how to print "%u" (only "%lu"), it just print a literal "u", eg:

Max number of cores passed to firmware: u (NR_CPUS = 2048)

instead of:

Max number of cores passed to firmware: 2048 (NR_CPUS = 2048)

This commit adds support for the missing formatters.

Fixes eae5f709a4d7 ("powerpc: Add __printf verification to prom_printf")
Reported-by Michael Ellerman <[email protected]>
Reported-by Stephen Rothwell <[email protected]>
Signed-off-by Mathieu Malaterre <[email protected]>

---
I've reviewed all formatters added in eae5f709a4d7 and only %u and %llx were actually missing (eg. llu or lld are not used)

 arch/powerpc/kernel/prom_init.c | 72 +++++++++++++++++++++++++++--------------
 1 file changed, 48 insertions(+), 24 deletions(-)
arch/powerpc/kernel/prom_init.c +48 -24
index 4d62f561f272..2c04516fe274 100644
@@ -301,6 +301,9 @@ static void __init prom_print(const char *msg)
 }
 
 
+/* both prom_print_hex & prom_print_dec takes an unsigned long as input so that
+ * we do not need __udivdi3 or __umoddi3 on 32bits
+ */
 static void __init prom_print_hex(unsigned long val)
 {
 	int i, nibbles = sizeof(val)*2;

@@ -341,6 +344,7 @@ static void __init prom_printf(const char *format, ...)
 	va_list args;
 	unsigned long v;
 	long vs;
+	int n = 0;
 
 	va_start(args, format);
 	for (p = format; *p != 0; p = q) {

@@ -359,6 +363,10 @@ static void __init prom_printf(const char *format, ...)
 		++q;
 		if (*q == 0)
 			break;
+		while (*q == 'l') {
+			++q;
+			++n;
+		}
 		switch (*q) {
 		case 's':
 			++q;

@@ -367,39 +375,55 @@ static void __init prom_printf(const char *format, ...)
 			break;
 		case 'x':
 			++q;
-			v = va_arg(args, unsigned long);
+			switch (n) {
+			case 0:
+				v = va_arg(args, unsigned int);
+				break;
+			case 1:
+				v = va_arg(args, unsigned long);
+				break;
+			case 2:
+			default:
+				v = va_arg(args, unsigned long long);
+				break;
+			}
 			prom_print_hex(v);
 			break;
-		case 'd':
+		case 'u':
 			++q;
-			vs = va_arg(args, int);
-			if (vs < 0) {
-				prom_print("-");
-				vs = -vs;
+			switch (n) {
+			case 0:
+				v = va_arg(args, unsigned int);
+				break;
+			case 1:
+				v = va_arg(args, unsigned long);
+				break;
+			case 2:
+			default:
+				v = va_arg(args, unsigned long long);
+				break;
 			}
-			prom_print_dec(vs);
+			prom_print_dec(v);
 			break;
-		case 'l':
+		case 'd':
 			++q;
-			if (*q == 0)
+			switch (n) {
+			case 0:
+				vs = va_arg(args, int);
 				break;
-			else if (*q == 'x') {
-				++q;
-				v = va_arg(args, unsigned long);
-				prom_print_hex(v);
-			} else if (*q == 'u') { /* '%lu' */
-				++q;
-				v = va_arg(args, unsigned long);
-				prom_print_dec(v);
-			} else if (*q == 'd') { /* %ld */
-				++q;
+			case 1:
 				vs = va_arg(args, long);
-				if (vs < 0) {
-					prom_print("-");
-					vs = -vs;
-				}
-				prom_print_dec(vs);
+				break;
+			case 2:
+			default:
+				vs = va_arg(args, long long);
+				break;
+			}
+			if (vs < 0) {
+				prom_print("-");
+				vs = -vs;
 			}
+			prom_print_dec(vs);
 			break;
 		}
 	}
Signature · 1 line
2.11.0
Applied
#1 lore raw
Quoted 20 lines · Mathieu Malaterre

In commit eae5f709a4d7 ("powerpc: Add __printf verification to prom_printf") __printf attribute was added to prom_printf(), which means GCC started warning about type/format mismatches. As part of that commit we changed some "%lx" formats to "%llx" where the type is actually unsigned long long.

Unfortunately prom_printf() doesn't know how to print "%llx", it just prints a literal "lx", eg:

reserved memory map:
lx - lx
lx - lx

prom_printf() also doesn't know how to print "%u" (only "%lu"), it just print a literal "u", eg:

Max number of cores passed to firmware: u (NR_CPUS = 2048)

instead of:

Quoted 8 lines

Max number of cores passed to firmware: 2048 (NR_CPUS = 2048)

This commit adds support for the missing formatters.

Fixes eae5f709a4d7 ("powerpc: Add __printf verification to prom_printf")
Reported-by Michael Ellerman <[email protected]>
Reported-by Stephen Rothwell <[email protected]>
Signed-off-by Mathieu Malaterre <[email protected]>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/8af1da40669609707303eecdb857f4

cheers