[PATCH 0/2] of: address: Fix empty resource handling in __of_address_resource_bounds()

[PATCH 0/2] of: address: Fix empty resource handling in __of_address_resource_bounds()

[Thomas Weißschuh]

Also add a kunit testcase to make sure the function works correctly now
and doesn't regress in the future.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
Thomas Weißschuh (2):
      of: address: Fix empty resource handling in __of_address_resource_bounds()
      of: address: Add kunit test for __of_address_resource_bounds()

 drivers/of/address.c    |  17 +++----
 drivers/of/of_private.h |   4 ++
 drivers/of/of_test.c    | 120 +++++++++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 132 insertions(+), 9 deletions(-)
---
base-commit: ffd294d346d185b70e28b1a28abe367bbfe53c04
change-id: 20250120-of-address-overflow-a59476362885

Best regards,
-- 
Thomas Weißschuh <thomas.weissschuh@linutronix.de>

[PATCH 1/2] of: address: Fix empty resource handling in __of_address_resource_bounds()

[Thomas Weißschuh]

"resource->end" needs to always be equal to "resource->start + size - 1".
The previous version of the function did not perform the "- 1" in case
of an empty resource.

Also make sure to allow an empty resource at address 0.

Reported-by: Basharath Hussain Khaja <basharath@couthit.com>
Closes: https://lore.kernel.org/lkml/20250108140414.13530-1-basharath@couthit.com/
Fixes: 1a52a094c2f0 ("of: address: Unify resource bounds overflow checking")
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 drivers/of/address.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/of/address.c b/drivers/of/address.c
index 8770004d9b085f1ff40f693d695d284a6ef3dfde..5c0663066a7f3816a05077f99124ca25e3c152d7 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -200,17 +200,15 @@ static u64 of_bus_pci_map(__be32 *addr, const __be32 *range, int na, int ns,
 
 static int __of_address_resource_bounds(struct resource *r, u64 start, u64 size)
 {
-	u64 end = start;
-
 	if (overflows_type(start, r->start))
 		return -EOVERFLOW;
-	if (size && check_add_overflow(end, size - 1, &end))
-		return -EOVERFLOW;
-	if (overflows_type(end, r->end))
-		return -EOVERFLOW;
 
 	r->start = start;
-	r->end = end;
+
+	if (!size)
+		r->end = wrapping_sub(typeof(r->end), r->start, 1);
+	else if (size && check_add_overflow(r->start, size - 1, &r->end))
+		return -EOVERFLOW;
 
 	return 0;
 }

-- 
2.48.1

Re: [PATCH 1/2] of: address: Fix empty resource handling in __of_address_resource_bounds()

[Rob Herring (Arm)]

On Mon, 20 Jan 2025 15:09:40 +0100, Thomas Weißschuh wrote:
> "resource->end" needs to always be equal to "resource->start + size - 1".
> The previous version of the function did not perform the "- 1" in case
> of an empty resource.
> 
> Also make sure to allow an empty resource at address 0.
> 
> Reported-by: Basharath Hussain Khaja <basharath@couthit.com>
> Closes: https://lore.kernel.org/lkml/20250108140414.13530-1-basharath@couthit.com/
> Fixes: 1a52a094c2f0 ("of: address: Unify resource bounds overflow checking")
> Cc: stable@vger.kernel.org
> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
> ---
>  drivers/of/address.c | 12 +++++-------
>  1 file changed, 5 insertions(+), 7 deletions(-)
> 

Applied, thanks!

Please resend the kunit test with 0-day issues fixed.

Rob

[PATCH 2/2] of: address: Add kunit test for __of_address_resource_bounds()

[Thomas Weißschuh]

The overflow checking has to deal with different datatypes and
edgecases. Add a new kunit testcase to make sure it works correctly.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>

---
Technically it's possible to run this unittest with !CONFIG_OF_ADDRESS,
so there is an explicit check inside the test.
It would also be possible to add a dedicated source file, but that
seemed like a lot of churn to me.
---
 drivers/of/address.c    |   5 +-
 drivers/of/of_private.h |   4 ++
 drivers/of/of_test.c    | 120 +++++++++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 127 insertions(+), 2 deletions(-)

diff --git a/drivers/of/address.c b/drivers/of/address.c
index 5c0663066a7f3816a05077f99124ca25e3c152d7..84b8d16919dc4aae966a09f7fe0606b2e51c3dde 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -16,6 +16,8 @@
 #include <linux/string.h>
 #include <linux/dma-direct.h> /* for bus_dma_region */
 
+#include <kunit/visibility.h>
+
 #include "of_private.h"
 
 /* Max address size we deal with */
@@ -198,7 +200,7 @@ static u64 of_bus_pci_map(__be32 *addr, const __be32 *range, int na, int ns,
 
 #endif /* CONFIG_PCI */
 
-static int __of_address_resource_bounds(struct resource *r, u64 start, u64 size)
+VISIBLE_IF_KUNIT int __of_address_resource_bounds(struct resource *r, u64 start, u64 size)
 {
 	if (overflows_type(start, r->start))
 		return -EOVERFLOW;
@@ -212,6 +214,7 @@ static int __of_address_resource_bounds(struct resource *r, u64 start, u64 size)
 
 	return 0;
 }
+EXPORT_SYMBOL_IF_KUNIT(__of_address_resource_bounds);
 
 /*
  * of_pci_range_to_resource - Create a resource from an of_pci_range
diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
index ea5a0951ec5e107bab265ab5f6c043e2bfb15ecc..0d29d71ac7c62ae91bfac0c8d1518622729575cd 100644
--- a/drivers/of/of_private.h
+++ b/drivers/of/of_private.h
@@ -188,4 +188,8 @@ void __init fdt_scan_reserved_mem_reg_nodes(void);
 
 bool of_fdt_device_is_available(const void *blob, unsigned long node);
 
+#if IS_ENABLED(CONFIG_KUNIT)
+int __of_address_resource_bounds(struct resource *r, u64 start, u64 size);
+#endif
+
 #endif /* _LINUX_OF_PRIVATE_H */
diff --git a/drivers/of/of_test.c b/drivers/of/of_test.c
index b0557ded838fdf70f0b679c31ead38f501371304..b8eb1d4b76fdf3a16fc5dd24f8e6ed0c3fca5e9c 100644
--- a/drivers/of/of_test.c
+++ b/drivers/of/of_test.c
@@ -2,6 +2,7 @@
 /*
  * KUnit tests for OF APIs
  */
+#include <linux/ioport.h>
 #include <linux/module.h>
 #include <linux/of.h>
 
@@ -54,8 +55,125 @@ static struct kunit_suite of_dtb_suite = {
 	.init = of_dtb_test_init,
 };
 
+struct of_address_resource_bounds_case {
+	u64 start;
+	u64 size;
+	int ret;
+
+	resource_size_t res_start;
+	resource_size_t res_end;
+};
+
+static void of_address_resource_bounds_case_desc(const struct of_address_resource_bounds_case *p,
+						 char *name)
+{
+	snprintf(name, KUNIT_PARAM_DESC_SIZE, "start=0x%016llx,size=0x%016llx", p->start, p->size);
+}
+
+static const struct of_address_resource_bounds_case of_address_resource_bounds_cases[] = {
+	{
+		.start = 0,
+		.size = 0,
+		.ret = 0,
+		.res_start = 0,
+		.res_end = -1,
+	},
+	{
+		.start = 0,
+		.size = 0x1000,
+		.ret = 0,
+		.res_start = 0,
+		.res_end = 0xfff,
+	},
+	{
+		.start = 0x1000,
+		.size = 0,
+		.ret = 0,
+		.res_start = 0x1000,
+		.res_end = 0xfff,
+	},
+	{
+		.start = 0x1000,
+		.size = 0x1000,
+		.ret = 0,
+		.res_start = 0x1000,
+		.res_end = 0x1fff,
+	},
+	{
+		.start = 1,
+		.size = RESOURCE_SIZE_MAX,
+		.ret = 0,
+		.res_start = 1,
+		.res_end = RESOURCE_SIZE_MAX,
+	},
+	{
+		.start = RESOURCE_SIZE_MAX,
+		.size = 1,
+		.ret = 0,
+		.res_start = RESOURCE_SIZE_MAX,
+		.res_end = RESOURCE_SIZE_MAX,
+	},
+	{
+		.start = 2,
+		.size = RESOURCE_SIZE_MAX,
+		.ret = -EOVERFLOW,
+	},
+	{
+		.start = RESOURCE_SIZE_MAX,
+		.size = 2,
+		.ret = -EOVERFLOW,
+	},
+	{
+		.start = 0x100000000ULL,
+		.size = 1,
+		.ret = sizeof(resource_size_t) > sizeof(u32) ? 0 : -EOVERFLOW,
+		.res_start = (resource_size_t)0x100000000,
+		.res_end = (resource_size_t)0x100000000,
+	},
+	{
+		.start = 0x1000,
+		.size = 0xffffffff,
+		.ret = sizeof(resource_size_t) > sizeof(u32) ? 0 : -EOVERFLOW,
+		.res_start = (resource_size_t)0x1000,
+		.res_end = (resource_size_t)0x100000ffe,
+	},
+};
+
+KUNIT_ARRAY_PARAM(of_address_resource_bounds,
+		  of_address_resource_bounds_cases, of_address_resource_bounds_case_desc);
+
+static void of_address_resource_bounds(struct kunit *test)
+{
+	const struct of_address_resource_bounds_case *param;
+	struct resource r; /* Intentionally uninitialized */
+	int ret;
+
+	if (!IS_ENABLED(CONFIG_OF_ADDRESS))
+		kunit_skip(test, "CONFIG_OF_ADDRESS not enabled\n");
+
+	param = test->param_value;
+
+	ret = __of_address_resource_bounds(&r, param->start, param->size);
+	KUNIT_EXPECT_EQ(test, param->ret, ret);
+	if (ret == 0) {
+		KUNIT_EXPECT_EQ(test, param->res_start, r.start);
+		KUNIT_EXPECT_EQ(test, param->res_end, r.end);
+		KUNIT_EXPECT_EQ(test, param->size, resource_size(&r));
+	}
+}
+
+static struct kunit_case of_address_test_cases[] = {
+	KUNIT_CASE_PARAM(of_address_resource_bounds, of_address_resource_bounds_gen_params),
+	{}
+};
+
+static struct kunit_suite of_address_suite = {
+	.name = "of_address",
+	.test_cases = of_address_test_cases,
+};
+
 kunit_test_suites(
-	&of_dtb_suite,
+	&of_dtb_suite, &of_address_suite,
 );
 MODULE_DESCRIPTION("KUnit tests for OF APIs");
 MODULE_LICENSE("GPL");

-- 
2.48.1

Re: [PATCH 2/2] of: address: Add kunit test for __of_address_resource_bounds()

[kernel test robot]

Hi Thomas,

kernel test robot noticed the following build errors:

[auto build test ERROR on ffd294d346d185b70e28b1a28abe367bbfe53c04]

url:    https://github.com/intel-lab-lkp/linux/commits/Thomas-Wei-schuh/of-address-Fix-empty-resource-handling-in-__of_address_resource_bounds/20250120-221141
base:   ffd294d346d185b70e28b1a28abe367bbfe53c04
patch link:    https://lore.kernel.org/r/20250120-of-address-overflow-v1-2-dd68dbf47bce%40linutronix.de
patch subject: [PATCH 2/2] of: address: Add kunit test for __of_address_resource_bounds()
config: riscv-randconfig-002-20250121 (https://download.01.org/0day-ci/archive/20250121/202501210330.aqouOniZ-lkp@intel.com/config)
compiler: riscv64-linux-gcc (GCC) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250121/202501210330.aqouOniZ-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202501210330.aqouOniZ-lkp@intel.com/

All errors (new ones prefixed by >>, old ones prefixed by <<):

>> ERROR: modpost: module of_test uses symbol __of_address_resource_bounds from namespace EXPORTED_FOR_KUNIT_TESTING, but does not import it.

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH 2/2] of: address: Add kunit test for __of_address_resource_bounds()

[kernel test robot]

Hi Thomas,

kernel test robot noticed the following build warnings:

[auto build test WARNING on ffd294d346d185b70e28b1a28abe367bbfe53c04]

url:    https://github.com/intel-lab-lkp/linux/commits/Thomas-Wei-schuh/of-address-Fix-empty-resource-handling-in-__of_address_resource_bounds/20250120-221141
base:   ffd294d346d185b70e28b1a28abe367bbfe53c04
patch link:    https://lore.kernel.org/r/20250120-of-address-overflow-v1-2-dd68dbf47bce%40linutronix.de
patch subject: [PATCH 2/2] of: address: Add kunit test for __of_address_resource_bounds()
config: powerpc-randconfig-001-20250121 (https://download.01.org/0day-ci/archive/20250121/202501210916.KXb12BAV-lkp@intel.com/config)
compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project c23f2417dc5f6dc371afb07af5627ec2a9d373a0)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250121/202501210916.KXb12BAV-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202501210916.KXb12BAV-lkp@intel.com/

All warnings (new ones prefixed by >>, old ones prefixed by <<):

WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/fpga/tests/fpga-mgr-test.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/fpga/tests/fpga-bridge-test.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/fpga/tests/fpga-region-test.o
>> WARNING: modpost: module of_test uses symbol __of_address_resource_bounds from namespace EXPORTED_FOR_KUNIT_TESTING, but does not import it.

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH 2/2] of: address: Add kunit test for __of_address_resource_bounds()

[kernel test robot]

Hi Thomas,

kernel test robot noticed the following build warnings:

[auto build test WARNING on ffd294d346d185b70e28b1a28abe367bbfe53c04]

url:    https://github.com/intel-lab-lkp/linux/commits/Thomas-Wei-schuh/of-address-Fix-empty-resource-handling-in-__of_address_resource_bounds/20250120-221141
base:   ffd294d346d185b70e28b1a28abe367bbfe53c04
patch link:    https://lore.kernel.org/r/20250120-of-address-overflow-v1-2-dd68dbf47bce%40linutronix.de
patch subject: [PATCH 2/2] of: address: Add kunit test for __of_address_resource_bounds()
config: arc-randconfig-r121-20250126 (https://download.01.org/0day-ci/archive/20250126/202501261727.x0aztept-lkp@intel.com/config)
compiler: arceb-elf-gcc (GCC) 13.2.0
reproduce: (https://download.01.org/0day-ci/archive/20250126/202501261727.x0aztept-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202501261727.x0aztept-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
>> drivers/of/of_test.c:130:47: sparse: sparse: cast truncates bits from constant value (100000000 becomes 0)
   drivers/of/of_test.c:131:45: sparse: sparse: cast truncates bits from constant value (100000000 becomes 0)
>> drivers/of/of_test.c:138:45: sparse: sparse: cast truncates bits from constant value (100000ffe becomes ffe)

vim +130 drivers/of/of_test.c

    72	
    73	static const struct of_address_resource_bounds_case of_address_resource_bounds_cases[] = {
    74		{
    75			.start = 0,
    76			.size = 0,
    77			.ret = 0,
    78			.res_start = 0,
    79			.res_end = -1,
    80		},
    81		{
    82			.start = 0,
    83			.size = 0x1000,
    84			.ret = 0,
    85			.res_start = 0,
    86			.res_end = 0xfff,
    87		},
    88		{
    89			.start = 0x1000,
    90			.size = 0,
    91			.ret = 0,
    92			.res_start = 0x1000,
    93			.res_end = 0xfff,
    94		},
    95		{
    96			.start = 0x1000,
    97			.size = 0x1000,
    98			.ret = 0,
    99			.res_start = 0x1000,
   100			.res_end = 0x1fff,
   101		},
   102		{
   103			.start = 1,
   104			.size = RESOURCE_SIZE_MAX,
   105			.ret = 0,
   106			.res_start = 1,
   107			.res_end = RESOURCE_SIZE_MAX,
   108		},
   109		{
   110			.start = RESOURCE_SIZE_MAX,
   111			.size = 1,
   112			.ret = 0,
   113			.res_start = RESOURCE_SIZE_MAX,
   114			.res_end = RESOURCE_SIZE_MAX,
   115		},
   116		{
   117			.start = 2,
   118			.size = RESOURCE_SIZE_MAX,
   119			.ret = -EOVERFLOW,
   120		},
   121		{
   122			.start = RESOURCE_SIZE_MAX,
   123			.size = 2,
   124			.ret = -EOVERFLOW,
   125		},
   126		{
   127			.start = 0x100000000ULL,
   128			.size = 1,
   129			.ret = sizeof(resource_size_t) > sizeof(u32) ? 0 : -EOVERFLOW,
 > 130			.res_start = (resource_size_t)0x100000000,
   131			.res_end = (resource_size_t)0x100000000,
   132		},
   133		{
   134			.start = 0x1000,
   135			.size = 0xffffffff,
   136			.ret = sizeof(resource_size_t) > sizeof(u32) ? 0 : -EOVERFLOW,
   137			.res_start = (resource_size_t)0x1000,
 > 138			.res_end = (resource_size_t)0x100000ffe,
   139		},
   140	};
   141	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki