[PATCH v3 0/2] x86: fix build warning int-to-pointer-cast

[PATCH v3 0/2] x86: fix build warning int-to-pointer-cast

[Vamshi K Sthambamkadi]

Please review.

Changes in v3:
 Copied kstrtoul & _kstrtoul correctly from lib/kstrtox.c to boot code
 as suggested by Borislav petkov <bp@alien8.de>

Changes in v2:
 On 32 bit, if supplied physical address overflow acpi_rsdp pointer
 return 0 from get_cmdline_acpi_rsdp()
 as suggested by Borislav Petkov <bp@alien8.de>

Changes in v1:
 Supressed build warning through Makefile change

Thank you!

Vamshi K Sthambamkadi (2):
  x86: add kstrtoul() converter func to boot code
  x86: fix build warning int-to-pointer-cast

 arch/x86/boot/compressed/acpi.c |  6 +++---
 arch/x86/boot/string.c          | 43 +++++++++++++++++++++++++++++++++++++++++
 arch/x86/boot/string.h          |  1 +
 3 files changed, 47 insertions(+), 3 deletions(-)

-- 
2.7.4

[PATCH v3 1/2] x86: add kstrtoul() converter func to boot code

[Vamshi K Sthambamkadi]

add str to unsigned long converter function to boot code.

Signed-off-by: Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@gmail.com>
---
 arch/x86/boot/string.c | 43 +++++++++++++++++++++++++++++++++++++++++++
 arch/x86/boot/string.h |  1 +
 2 files changed, 44 insertions(+)

diff --git a/arch/x86/boot/string.c b/arch/x86/boot/string.c
index 8272a44..e06ebe1 100644
--- a/arch/x86/boot/string.c
+++ b/arch/x86/boot/string.c
@@ -335,3 +335,46 @@ int kstrtoull(const char *s, unsigned int base, unsigned long long *res)
 		s++;
 	return _kstrtoull(s, base, res);
 }
+
+/* Internal, do not use. */
+int _kstrtoul(const char *s, unsigned int base, unsigned long *res)
+{
+	unsigned long long tmp;
+	int rv;
+
+	rv = kstrtoull(s, base, &tmp);
+	if (rv < 0)
+		return rv;
+	if (tmp != (unsigned long)tmp)
+		return -ERANGE;
+	*res = tmp;
+	return 0;
+}
+
+/**
+ * kstrtoul - convert a string to an unsigned long
+ * @s: The start of the string. The string must be null-terminated, and may also
+ *  include a single newline before its terminating null. The first character
+ *  may also be a plus sign, but not a minus sign.
+ * @base: The number base to use. The maximum supported base is 16. If base is
+ *  given as 0, then the base of the string is automatically detected with the
+ *  conventional semantics - If it begins with 0x the number will be parsed as a
+ *  hexadecimal (case insensitive), if it otherwise begins with 0, it will be
+ *  parsed as an octal number. Otherwise it will be parsed as a decimal.
+ * @res: Where to write the result of the conversion on success.
+ *
+ * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
+ * Used as a replacement for the simple_strtoull.
+ */
+int kstrtoul(const char *s, unsigned int base, unsigned long *res)
+{
+	/*
+	 * We want to shortcut function call, but
+	 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0.
+	 */
+	if (sizeof(unsigned long) == sizeof(unsigned long long) &&
+	    __alignof__(unsigned long) == __alignof__(unsigned long long))
+		return kstrtoull(s, base, (unsigned long long *)res);
+	else
+		return _kstrtoul(s, base, res);
+}
diff --git a/arch/x86/boot/string.h b/arch/x86/boot/string.h
index 38d8f2f..e8dd239 100644
--- a/arch/x86/boot/string.h
+++ b/arch/x86/boot/string.h
@@ -30,4 +30,5 @@ extern unsigned long long simple_strtoull(const char *cp, char **endp,
 					  unsigned int base);
 
 int kstrtoull(const char *s, unsigned int base, unsigned long long *res);
+int kstrtoul(const char *s, unsigned int base, unsigned long *res);
 #endif /* BOOT_STRING_H */
-- 
2.7.4

[PATCH v3 2/2] x86: fix build warning int-to-pointer-cast

[Vamshi K Sthambamkadi]

Fix warning on x86_32:
arch/x86/boot/compressed/acpi.c:316:9: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]

This is because on 32 bit, cast of acpi_physical_address(u64) to rsdp
pointer in get_acpi_srat_table() triggers this warning.

Signed-off-by: Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@gmail.com>
---
 arch/x86/boot/compressed/acpi.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/boot/compressed/acpi.c b/arch/x86/boot/compressed/acpi.c
index ef2ad72..2fd81f1 100644
--- a/arch/x86/boot/compressed/acpi.c
+++ b/arch/x86/boot/compressed/acpi.c
@@ -280,9 +280,9 @@ acpi_physical_address get_rsdp_addr(void)
  */
 #define MAX_ADDR_LEN 19
 
-static acpi_physical_address get_cmdline_acpi_rsdp(void)
+static unsigned long get_cmdline_acpi_rsdp(void)
 {
-	acpi_physical_address addr = 0;
+	unsigned long addr = 0;
 
 #ifdef CONFIG_KEXEC
 	char val[MAX_ADDR_LEN] = { };
@@ -292,7 +292,7 @@ static acpi_physical_address get_cmdline_acpi_rsdp(void)
 	if (ret < 0)
 		return 0;
 
-	if (kstrtoull(val, 16, &addr))
+	if (kstrtoul(val, 16, &addr))
 		return 0;
 #endif
 	return addr;
-- 
2.7.4

[tip: x86/boot] x86/boot: Fix -Wint-to-pointer-cast build warning

[tip-bot2 for Vamshi K Sthambamkadi]

The following commit has been merged into the x86/boot branch of tip:

Commit-ID:     40ba9309c76f29d012a5cc0cf938f8ff7dc6fef2
Gitweb:        https://git.kernel.org/tip/40ba9309c76f29d012a5cc0cf938f8ff7dc6fef2
Author:        Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@gmail.com>
AuthorDate:    Thu, 23 Apr 2020 18:09:48 +05:30
Committer:     Borislav Petkov <bp@suse.de>
CommitterDate: Mon, 04 May 2020 15:22:16 +02:00

x86/boot: Fix -Wint-to-pointer-cast build warning

Fix this warning when building 32-bit with

CONFIG_RANDOMIZE_BASE=y
CONFIG_MEMORY_HOTREMOVE=y

  arch/x86/boot/compressed/acpi.c:316:9: warning: \
    cast to pointer from integer of different size [-Wint-to-pointer-cast]

Have get_cmdline_acpi_rsdp() return unsigned long which is the proper
type to convert to a pointer of the respective width.

 [ bp: Rewrite commit message, touch ups. ]

Signed-off-by: Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/1587645588-7130-3-git-send-email-vamshi.k.sthambamkadi@gmail.com
---
 arch/x86/boot/compressed/acpi.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/arch/x86/boot/compressed/acpi.c b/arch/x86/boot/compressed/acpi.c
index ef2ad72..8bcbcee 100644
--- a/arch/x86/boot/compressed/acpi.c
+++ b/arch/x86/boot/compressed/acpi.c
@@ -280,9 +280,9 @@ acpi_physical_address get_rsdp_addr(void)
  */
 #define MAX_ADDR_LEN 19
 
-static acpi_physical_address get_cmdline_acpi_rsdp(void)
+static unsigned long get_cmdline_acpi_rsdp(void)
 {
-	acpi_physical_address addr = 0;
+	unsigned long addr = 0;
 
 #ifdef CONFIG_KEXEC
 	char val[MAX_ADDR_LEN] = { };
@@ -292,7 +292,7 @@ static acpi_physical_address get_cmdline_acpi_rsdp(void)
 	if (ret < 0)
 		return 0;
 
-	if (kstrtoull(val, 16, &addr))
+	if (boot_kstrtoul(val, 16, &addr))
 		return 0;
 #endif
 	return addr;
@@ -314,7 +314,6 @@ static unsigned long get_acpi_srat_table(void)
 	 * different ideas about whether to trust a command-line parameter.
 	 */
 	rsdp = (struct acpi_table_rsdp *)get_cmdline_acpi_rsdp();
-
 	if (!rsdp)
 		rsdp = (struct acpi_table_rsdp *)(long)
 			boot_params->acpi_rsdp_addr;

[tip: x86/boot] x86/boot: Add kstrtoul() from lib/

[tip-bot2 for Vamshi K Sthambamkadi]

The following commit has been merged into the x86/boot branch of tip:

Commit-ID:     5fafbebc86a0043ca5bbd8d3ce4f63dc5a02ad8e
Gitweb:        https://git.kernel.org/tip/5fafbebc86a0043ca5bbd8d3ce4f63dc5a02ad8e
Author:        Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@gmail.com>
AuthorDate:    Thu, 23 Apr 2020 18:09:47 +05:30
Committer:     Borislav Petkov <bp@suse.de>
CommitterDate: Mon, 04 May 2020 15:19:07 +02:00

x86/boot: Add kstrtoul() from lib/

Add kstrtoul() to ../boot/ to be used by facilities there too.

 [
   bp: Massage, make _kstrtoul() static. Prepend function names with
   "boot_". This is a temporary workaround for build errors like:

   ld: arch/x86/boot/compressed/acpi.o: in function `count_immovable_mem_regions':
   acpi.c:(.text+0x463): undefined reference to `_kstrtoul'
   make[2]: *** [arch/x86/boot/compressed/Makefile:117: arch/x86/boot/compressed/vmlinux] Error 1

   due to the namespace clash between x86/boot/ and kernel proper.
   Future reorg will get rid of the linux/linux/ namespace as much as
   possible so that x86/boot/ can be independent from kernel proper. ]

Signed-off-by: Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/1587645588-7130-2-git-send-email-vamshi.k.sthambamkadi@gmail.com
---
 arch/x86/boot/string.c | 43 ++++++++++++++++++++++++++++++++++++++++-
 arch/x86/boot/string.h |  1 +-
 2 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/arch/x86/boot/string.c b/arch/x86/boot/string.c
index 8272a44..8a3fff9 100644
--- a/arch/x86/boot/string.c
+++ b/arch/x86/boot/string.c
@@ -117,7 +117,6 @@ static unsigned int simple_guess_base(const char *cp)
  * @endp: A pointer to the end of the parsed string will be placed here
  * @base: The number base to use
  */
-
 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
 {
 	unsigned long long result = 0;
@@ -335,3 +334,45 @@ int kstrtoull(const char *s, unsigned int base, unsigned long long *res)
 		s++;
 	return _kstrtoull(s, base, res);
 }
+
+static int _kstrtoul(const char *s, unsigned int base, unsigned long *res)
+{
+	unsigned long long tmp;
+	int rv;
+
+	rv = kstrtoull(s, base, &tmp);
+	if (rv < 0)
+		return rv;
+	if (tmp != (unsigned long)tmp)
+		return -ERANGE;
+	*res = tmp;
+	return 0;
+}
+
+/**
+ * kstrtoul - convert a string to an unsigned long
+ * @s: The start of the string. The string must be null-terminated, and may also
+ *  include a single newline before its terminating null. The first character
+ *  may also be a plus sign, but not a minus sign.
+ * @base: The number base to use. The maximum supported base is 16. If base is
+ *  given as 0, then the base of the string is automatically detected with the
+ *  conventional semantics - If it begins with 0x the number will be parsed as a
+ *  hexadecimal (case insensitive), if it otherwise begins with 0, it will be
+ *  parsed as an octal number. Otherwise it will be parsed as a decimal.
+ * @res: Where to write the result of the conversion on success.
+ *
+ * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
+ * Used as a replacement for the simple_strtoull.
+ */
+int boot_kstrtoul(const char *s, unsigned int base, unsigned long *res)
+{
+	/*
+	 * We want to shortcut function call, but
+	 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0.
+	 */
+	if (sizeof(unsigned long) == sizeof(unsigned long long) &&
+	    __alignof__(unsigned long) == __alignof__(unsigned long long))
+		return kstrtoull(s, base, (unsigned long long *)res);
+	else
+		return _kstrtoul(s, base, res);
+}
diff --git a/arch/x86/boot/string.h b/arch/x86/boot/string.h
index 38d8f2f..995f7b7 100644
--- a/arch/x86/boot/string.h
+++ b/arch/x86/boot/string.h
@@ -30,4 +30,5 @@ extern unsigned long long simple_strtoull(const char *cp, char **endp,
 					  unsigned int base);
 
 int kstrtoull(const char *s, unsigned int base, unsigned long long *res);
+int boot_kstrtoul(const char *s, unsigned int base, unsigned long *res);
 #endif /* BOOT_STRING_H */