[coreboot-gerrit] Change in ...coreboot[master]: libpayload: Deduplicate strtol and strtoull

[Julius Werner (Code Review)]

Hello Nico Huber,

I'd like you to do a code review. Please visit

https://review.coreboot.org/c/coreboot/+/32086

to review the following change.

Change subject: libpayload: Deduplicate strtol and strtoull
......................................................................

libpayload: Deduplicate strtol and strtoull

Our strtol() and strtoull() function contain almost exactly the same
code. This is a) bad in general and b) may cause the code to get out of
sync, such as it recently happened with CB:32029.

This patch changes strtol() to be based on strtoull() so that the main
parsing code exists only once, and also adds a strtoll() to round off
the library. Also fix the bounds imposed by strtoul() to be based on the
actual length of a 'long', not hardcoded to 32-bits (which is not
equivalent on all architectures).

Change-Id: I919c65a773cecdb11739c3f22dd0d182ed50c07f
Signed-off-by: Julius Werner 
---
M payloads/libpayload/include/stdlib.h
M payloads/libpayload/libc/string.c
2 files changed, 26 insertions(+), 40 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/86/32086/1

diff --git a/payloads/libpayload/include/stdlib.h b/payloads/libpayload/include/stdlib.h
index aaacc87..d4a7844 100644
--- a/payloads/libpayload/include/stdlib.h
+++ b/payloads/libpayload/include/stdlib.h
@@ -196,6 +196,7 @@
  * @{
  */
 long int strtol(const char *s, char **nptr, int base);
+long long int strtoll(const char *s, char **nptr, int base);
 unsigned long int strtoul(const char *s, char **nptr, int base);
 unsigned long long int strtoull(const char *s, char **nptr, int base);
 long atol(const char *nptr);
diff --git a/payloads/libpayload/libc/string.c b/payloads/libpayload/libc/string.c
index f563f63..6c257cb 100644
--- a/payloads/libpayload/libc/string.c
+++ b/payloads/libpayload/libc/string.c
@@ -33,6 +33,7 @@
 #include <string.h>
 #include <ctype.h>
 #include <inttypes.h>
+#include <limits.h>
 #include <errno.h>

/**
@@ -419,59 +420,43 @@
  * @return A signed integer representation of the string
  */

-long int strtol(const char *ptr, char **endptr, int base)
+long long int strtoll(const char *orig_ptr, char **endptr, int base)
 {
-	int ret = 0;
-	int negative = 1;
-
-	if (endptr != NULL)
-		*endptr = (char *) ptr;
+	const char *ptr = orig_ptr;
+	int is_negative = 0;

/* Purge whitespace */

for( ; *ptr && isspace(*ptr); ptr++);

if (ptr[0] == '-') {
-		negative = -1;
+		is_negative = 1;
    	ptr++;
    }

-	if (!*ptr)
-		return 0;
+	unsigned long long uval = strtoull(ptr, endptr, base);

-	/* Determine the base */
+	/* If the whole string is unparseable, endptr should point to start. */
+	if (endptr && *endptr == ptr)
+		*endptr = (char *)orig_ptr;

-	if (base == 0) {
-		if (ptr[0] == '0' && (ptr[1] == 'x' || ptr[1] == 'X'))
-			base = 16;
-		else if (ptr[0] == '0') {
-			base = 8;
-			ptr++;
-		}
-		else
-			base = 10;
-	}
+	if (uval > (unsigned long long)LLONG_MAX + !!is_negative)
+		uval = (unsigned long long)LLONG_MAX + !!is_negative;

-	/* Base 16 allows the 0x on front - so skip over it */
+	if (is_negative)
+		return -uval;
+	else
+		return uval;
+}

-	if (base == 16) {
-		if (ptr[0] == '0' && (ptr[1] == 'x' || ptr[1] == 'X'))
-			ptr += 2;
-	}
-
-	/* If the first character isn't valid, then don't
-	 * bother */
-
-	if (!*ptr || !_valid(*ptr, base))
-		return 0;
-
-	for( ; *ptr && _valid(*ptr, base); ptr++)
-		ret = (ret * base) + _offset(*ptr, base);
-
-	if (endptr != NULL)
-		*endptr = (char *) ptr;
-
-	return ret * negative;
+long int strtol(const char *ptr, char **endptr, int base)
+{
+	long long int val = strtoll(ptr, endptr, base);
+	if (val > LONG_MAX)
+		return LONG_MAX;
+	if (val < LONG_MIN)
+		return LONG_MIN;
+	return val;
 }

long atol(const char *nptr)
@@ -534,7 +519,7 @@
 unsigned long int strtoul(const char *ptr, char **endptr, int base)
 {
    unsigned long long val = strtoull(ptr, endptr, base);
-	if (val > UINT32_MAX) return UINT32_MAX;
+	if (val > ULONG_MAX) return ULONG_MAX;
    return val;
 }