printk: fix printing of long long types

64-bit types were not being handled properly and depending on the
calling convention could result in garbage values being printed.

We still truncate these to 32-bit values, the predominant use-case
is printing timestamp delta values which generally fit in a 32-bit
value. However we are no longer printing random stuff.

Test case for printk() updated appripriately to catch this regression.

Signed-off-by: Andrew Boie <[email protected]>

Author: Andrew Boie

misc/printk.c

@@ -90,6 +90,7 @@ void _vprintk(out_func_t out, void *ctx, const char *fmt, va_list ap)
 	int might_format = 0; /* 1 if encountered a '%' */
 	enum pad_type padding = PAD_NONE;
 	int min_width = -1;
+	int long_ctr = 0;
 
 	/* fmt has already been adjusted if needed */
 
@@ -101,6 +102,7 @@ void _vprintk(out_func_t out, void *ctx, const char *fmt, va_list ap)
 				might_format = 1;
 				min_width = -1;
 				padding = PAD_NONE;
+				long_ctr = 0;
 			}
 		} else {
 			switch (*fmt) {
@@ -124,14 +126,21 @@ void _vprintk(out_func_t out, void *ctx, const char *fmt, va_list ap)
 					padding = PAD_SPACE_BEFORE;
 				}
 				goto still_might_format;
-			case 'z':
 			case 'l':
+				long_ctr++;
+				/* Fall through */
+			case 'z':
 			case 'h':
 				/* FIXME: do nothing for these modifiers */
 				goto still_might_format;
 			case 'd':
 			case 'i': {
-				long d = va_arg(ap, long);
+				long d;
+				if (long_ctr < 2) {
+					d = va_arg(ap, long);
+				} else {
+					d = (long)va_arg(ap, long long);
+				}
 
 				if (d < 0) {
 					out((int)'-', ctx);
@@ -143,8 +152,14 @@ void _vprintk(out_func_t out, void *ctx, const char *fmt, va_list ap)
 				break;
 			}
 			case 'u': {
-				unsigned long u = va_arg(
-					ap, unsigned long);
+				unsigned long u;
+
+				if (long_ctr < 2) {
+					u = va_arg(ap, unsigned long);
+				} else {
+					u = (unsigned long)va_arg(ap,
+							unsigned long long);
+				}
 				_printk_dec_ulong(out, ctx, u, padding,
 						  min_width);
 				break;
@@ -158,8 +173,15 @@ void _vprintk(out_func_t out, void *ctx, const char *fmt, va_list ap)
 				  /* Fall through */
 			case 'x':
 			case 'X': {
-				unsigned long x = va_arg(
-					ap, unsigned long);
+				unsigned long x;
+
+				if (long_ctr < 2) {
+					x = va_arg(ap, unsigned long);
+				} else {
+					x = (unsigned long)va_arg(ap,
+							unsigned long long);
+				}
+
 				_printk_hex_ulong(out, ctx, x, padding,
 						  min_width);
 				break;

tests/kernel/common/src/printk.c

@@ -25,6 +25,7 @@ char *expected = "22 113 10000 32768 40000 22\n"
 		 "42 42   42       42\n"
 		 "42 42 0042 00000042\n"
 		 "255     42    abcdef  0x0000002a      42\n"
+		 "-1 4294967295 ffffffff\n"
 ;
 
 
@@ -61,6 +62,8 @@ void printk_test(void)
 {
 	int count;
 
+	printk("%lld %llu %llx",
+			  1LL, -1ULL, -1ULL);
 	_old_char_out = __printk_get_hook();
 	__printk_hook_install(ram_console_out);
 
@@ -74,6 +77,7 @@ void printk_test(void)
 	printk("%u %2u %4u %8u\n", 42, 42, 42, 42);
 	printk("%u %02u %04u %08u\n", 42, 42, 42, 42);
 	printk("%-8u%-6d%-4x%-2p%8d\n", 0xFF, 42, 0xABCDEF, (char *)42, 42);
+	printk("%lld %llu %llx\n", -1LL, -1ULL, -1ULL);
 
 	ram_console[pos] = '\0';
 	zassert_true((strcmp(ram_console, expected) == 0), "printk failed");
@@ -103,6 +107,9 @@ void printk_test(void)
 	count += snprintk(ram_console + count, sizeof(ram_console) - count,
 			  "%-8u%-6d%-4x%-2p%8d\n",
 			  0xFF, 42, 0xABCDEF, (char *)42, 42);
+	count += snprintk(ram_console + count, sizeof(ram_console) - count,
+			  "%lld %llu %llx\n",
+			  -1LL, -1ULL, -1ULL);
 	ram_console[count] = '\0';
 	zassert_true((strcmp(ram_console, expected) == 0), "snprintk failed");
 }