[PATCH v3 0/2] bitmap: Fix return values to be unsigned

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* [PATCH v3 0/2] bitmap: Fix return values to be unsigned
@ 2022-05-18 20:52 Kees Cook
  2022-05-18 20:52 ` [PATCH v3 1/2] " Kees Cook
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: Kees Cook @ 2022-05-18 20:52 UTC (permalink / raw)
  To: Yury Norov
  Cc: Kees Cook, Christophe de Dinechin, Rasmus Villemoes,
	Alexey Dobriyan, Andy Shevchenko, Andrew Morton, Zhen Lei,
	linux-kernel, linux-hardening

Hi,

v1: https://lore.kernel.org/lkml/20220517035411.31144-1-keescook@chromium.org
v2: https://lore.kernel.org/lkml/20220517212234.868181-1-keescook@chromium.org
v3:
 - Update missed int variable to unsigned int
 - Update tools/ bitmaps code to match
 - Adjust whitespace a bit

Rationale repeated from the last patch:

Both nodemask and bitmap routines had mixed return values that provided
potentially signed results that could never happen. This was leading to
the compiler getting confusing about the range of possible return values
(it was thinking things could be negative where they could not be). Fix
all the nodemask and bitmap routines that should be returning unsigned
(or bool) values. Silences GCC 12 warnings:

 mm/swapfile.c: In function ‘setup_swap_info’:
 mm/swapfile.c:2291:47: error: array subscript -1 is below array bounds of ‘struct plist_node[]’ [-Werror=array-bounds]
  2291 |                                 p->avail_lists[i].prio = 1;
       |                                 ~~~~~~~~~~~~~~^~~
 In file included from mm/swapfile.c:16:
 ./include/linux/swap.h:292:27: note: while referencing ‘avail_lists’
   292 |         struct plist_node avail_lists[]; /*
       |                           ^~~~~~~~~~~


I note that Alexey and Rasmus have touched on this area in the past,
fixing up node ids to be unsigned:

ce0725f78a56 ("numa: make "nr_online_nodes" unsigned int")
b9726c26dc21 ("numa: make "nr_node_ids" unsigned int")
33c4fa8c6763 ("linux/nodemask.h: update bitmap wrappers to take unsigned int")

-Kees


Kees Cook (2):
  bitmap: Fix return values to be unsigned
  nodemask: Fix return values to be unsigned

 include/linux/bitmap.h       | 25 ++++++++++++------------
 include/linux/nodemask.h     | 38 ++++++++++++++++++------------------
 lib/bitmap.c                 | 30 ++++++++++++++--------------
 lib/nodemask.c               |  4 ++--
 tools/include/linux/bitmap.h | 17 ++++++++--------
 tools/lib/bitmap.c           | 20 +++++++++----------
 6 files changed, 68 insertions(+), 66 deletions(-)

-- 
2.32.0


^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH v3 1/2] bitmap: Fix return values to be unsigned
  2022-05-18 20:52 [PATCH v3 0/2] bitmap: Fix return values to be unsigned Kees Cook
@ 2022-05-18 20:52 ` Kees Cook
  2022-05-18 20:52 ` [PATCH v3 2/2] nodemask: " Kees Cook
  2022-05-18 21:55 ` [PATCH v3 0/2] bitmap: " Yury Norov
  2 siblings, 0 replies; 4+ messages in thread
From: Kees Cook @ 2022-05-18 20:52 UTC (permalink / raw)
  To: Yury Norov
  Cc: Kees Cook, Rasmus Villemoes, Christophe de Dinechin,
	Alexey Dobriyan, Andy Shevchenko, Andrew Morton, Zhen Lei,
	linux-kernel, linux-hardening

Both nodemask and bitmap routines had mixed return values that provided
potentially signed return values that could never happen. This was
leading to the compiler getting confusing about the range of possible
return values (it was thinking things could be negative where they could
not be). In preparation for fixing nodemask, fix all the bitmap routines
that should be returning unsigned (or bool) values.

Cc: Yury Norov <yury.norov@gmail.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Christophe de Dinechin <dinechin@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 include/linux/bitmap.h       | 25 +++++++++++++------------
 lib/bitmap.c                 | 30 +++++++++++++++---------------
 tools/include/linux/bitmap.h | 17 +++++++++--------
 tools/lib/bitmap.c           | 20 ++++++++++----------
 4 files changed, 47 insertions(+), 45 deletions(-)

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index 7dba0847510c..8303eb5604ca 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -132,8 +132,8 @@ unsigned long *devm_bitmap_zalloc(struct device *dev,
  * lib/bitmap.c provides these functions:
  */
 
-int __bitmap_equal(const unsigned long *bitmap1,
-		   const unsigned long *bitmap2, unsigned int nbits);
+bool __bitmap_equal(const unsigned long *bitmap1,
+		    const unsigned long *bitmap2, unsigned int nbits);
 bool __pure __bitmap_or_equal(const unsigned long *src1,
 			      const unsigned long *src2,
 			      const unsigned long *src3,
@@ -157,10 +157,10 @@ int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
 void __bitmap_replace(unsigned long *dst,
 		      const unsigned long *old, const unsigned long *new,
 		      const unsigned long *mask, unsigned int nbits);
-int __bitmap_intersects(const unsigned long *bitmap1,
-			const unsigned long *bitmap2, unsigned int nbits);
-int __bitmap_subset(const unsigned long *bitmap1,
-		    const unsigned long *bitmap2, unsigned int nbits);
+bool __bitmap_intersects(const unsigned long *bitmap1,
+			 const unsigned long *bitmap2, unsigned int nbits);
+bool __bitmap_subset(const unsigned long *bitmap1,
+		     const unsigned long *bitmap2, unsigned int nbits);
 int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
 void __bitmap_set(unsigned long *map, unsigned int start, int len);
 void __bitmap_clear(unsigned long *map, unsigned int start, int len);
@@ -331,8 +331,8 @@ static inline void bitmap_complement(unsigned long *dst, const unsigned long *sr
 #endif
 #define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1)
 
-static inline int bitmap_equal(const unsigned long *src1,
-			const unsigned long *src2, unsigned int nbits)
+static inline bool bitmap_equal(const unsigned long *src1,
+				const unsigned long *src2, unsigned int nbits)
 {
 	if (small_const_nbits(nbits))
 		return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
@@ -362,8 +362,9 @@ static inline bool bitmap_or_equal(const unsigned long *src1,
 	return !(((*src1 | *src2) ^ *src3) & BITMAP_LAST_WORD_MASK(nbits));
 }
 
-static inline int bitmap_intersects(const unsigned long *src1,
-			const unsigned long *src2, unsigned int nbits)
+static inline bool bitmap_intersects(const unsigned long *src1,
+				     const unsigned long *src2,
+				     unsigned int nbits)
 {
 	if (small_const_nbits(nbits))
 		return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
@@ -371,8 +372,8 @@ static inline int bitmap_intersects(const unsigned long *src1,
 		return __bitmap_intersects(src1, src2, nbits);
 }
 
-static inline int bitmap_subset(const unsigned long *src1,
-			const unsigned long *src2, unsigned int nbits)
+static inline bool bitmap_subset(const unsigned long *src1,
+				 const unsigned long *src2, unsigned int nbits)
 {
 	if (small_const_nbits(nbits))
 		return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
diff --git a/lib/bitmap.c b/lib/bitmap.c
index 0d5c2ece0bcb..2692fd43c125 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -45,19 +45,19 @@
  * for the best explanations of this ordering.
  */
 
-int __bitmap_equal(const unsigned long *bitmap1,
-		const unsigned long *bitmap2, unsigned int bits)
+bool __bitmap_equal(const unsigned long *bitmap1,
+		    const unsigned long *bitmap2, unsigned int bits)
 {
 	unsigned int k, lim = bits/BITS_PER_LONG;
 	for (k = 0; k < lim; ++k)
 		if (bitmap1[k] != bitmap2[k])
-			return 0;
+			return false;
 
 	if (bits % BITS_PER_LONG)
 		if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
-			return 0;
+			return false;
 
-	return 1;
+	return true;
 }
 EXPORT_SYMBOL(__bitmap_equal);
 
@@ -303,33 +303,33 @@ void __bitmap_replace(unsigned long *dst,
 }
 EXPORT_SYMBOL(__bitmap_replace);
 
-int __bitmap_intersects(const unsigned long *bitmap1,
-			const unsigned long *bitmap2, unsigned int bits)
+bool __bitmap_intersects(const unsigned long *bitmap1,
+			 const unsigned long *bitmap2, unsigned int bits)
 {
 	unsigned int k, lim = bits/BITS_PER_LONG;
 	for (k = 0; k < lim; ++k)
 		if (bitmap1[k] & bitmap2[k])
-			return 1;
+			return true;
 
 	if (bits % BITS_PER_LONG)
 		if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
-			return 1;
-	return 0;
+			return true;
+	return false;
 }
 EXPORT_SYMBOL(__bitmap_intersects);
 
-int __bitmap_subset(const unsigned long *bitmap1,
-		    const unsigned long *bitmap2, unsigned int bits)
+bool __bitmap_subset(const unsigned long *bitmap1,
+		     const unsigned long *bitmap2, unsigned int bits)
 {
 	unsigned int k, lim = bits/BITS_PER_LONG;
 	for (k = 0; k < lim; ++k)
 		if (bitmap1[k] & ~bitmap2[k])
-			return 0;
+			return false;
 
 	if (bits % BITS_PER_LONG)
 		if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
-			return 0;
-	return 1;
+			return false;
+	return true;
 }
 EXPORT_SYMBOL(__bitmap_subset);
 
diff --git a/tools/include/linux/bitmap.h b/tools/include/linux/bitmap.h
index ea97804d04d4..afdf93bebaaf 100644
--- a/tools/include/linux/bitmap.h
+++ b/tools/include/linux/bitmap.h
@@ -16,11 +16,11 @@ void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
 		 const unsigned long *bitmap2, int bits);
 int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
 		 const unsigned long *bitmap2, unsigned int bits);
-int __bitmap_equal(const unsigned long *bitmap1,
-		   const unsigned long *bitmap2, unsigned int bits);
+bool __bitmap_equal(const unsigned long *bitmap1,
+		    const unsigned long *bitmap2, unsigned int bits);
 void bitmap_clear(unsigned long *map, unsigned int start, int len);
-int __bitmap_intersects(const unsigned long *bitmap1,
-			const unsigned long *bitmap2, unsigned int bits);
+bool __bitmap_intersects(const unsigned long *bitmap1,
+			 const unsigned long *bitmap2, unsigned int bits);
 
 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
 #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
@@ -162,8 +162,8 @@ static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
 #define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1)
 #define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0)
 
-static inline int bitmap_equal(const unsigned long *src1,
-			const unsigned long *src2, unsigned int nbits)
+static inline bool bitmap_equal(const unsigned long *src1,
+				const unsigned long *src2, unsigned int nbits)
 {
 	if (small_const_nbits(nbits))
 		return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
@@ -173,8 +173,9 @@ static inline int bitmap_equal(const unsigned long *src1,
 	return __bitmap_equal(src1, src2, nbits);
 }
 
-static inline int bitmap_intersects(const unsigned long *src1,
-			const unsigned long *src2, unsigned int nbits)
+static inline bool bitmap_intersects(const unsigned long *src1,
+				     const unsigned long *src2,
+				     unsigned int nbits)
 {
 	if (small_const_nbits(nbits))
 		return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
diff --git a/tools/lib/bitmap.c b/tools/lib/bitmap.c
index db466ef7be9d..354f8cdc0880 100644
--- a/tools/lib/bitmap.c
+++ b/tools/lib/bitmap.c
@@ -72,31 +72,31 @@ int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
 	return result != 0;
 }
 
-int __bitmap_equal(const unsigned long *bitmap1,
-		const unsigned long *bitmap2, unsigned int bits)
+bool __bitmap_equal(const unsigned long *bitmap1,
+		    const unsigned long *bitmap2, unsigned int bits)
 {
 	unsigned int k, lim = bits/BITS_PER_LONG;
 	for (k = 0; k < lim; ++k)
 		if (bitmap1[k] != bitmap2[k])
-			return 0;
+			return false;
 
 	if (bits % BITS_PER_LONG)
 		if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
-			return 0;
+			return false;
 
-	return 1;
+	return true;
 }
 
-int __bitmap_intersects(const unsigned long *bitmap1,
-			const unsigned long *bitmap2, unsigned int bits)
+bool __bitmap_intersects(const unsigned long *bitmap1,
+			 const unsigned long *bitmap2, unsigned int bits)
 {
 	unsigned int k, lim = bits/BITS_PER_LONG;
 	for (k = 0; k < lim; ++k)
 		if (bitmap1[k] & bitmap2[k])
-			return 1;
+			return true;
 
 	if (bits % BITS_PER_LONG)
 		if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
-			return 1;
-	return 0;
+			return true;
+	return false;
 }
-- 
2.32.0


^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH v3 2/2] nodemask: Fix return values to be unsigned
  2022-05-18 20:52 [PATCH v3 0/2] bitmap: Fix return values to be unsigned Kees Cook
  2022-05-18 20:52 ` [PATCH v3 1/2] " Kees Cook
@ 2022-05-18 20:52 ` Kees Cook
  2022-05-18 21:55 ` [PATCH v3 0/2] bitmap: " Yury Norov
  2 siblings, 0 replies; 4+ messages in thread
From: Kees Cook @ 2022-05-18 20:52 UTC (permalink / raw)
  To: Yury Norov
  Cc: Kees Cook, Christophe de Dinechin, Alexey Dobriyan,
	Andy Shevchenko, Rasmus Villemoes, Andrew Morton, Zhen Lei,
	linux-kernel, linux-hardening

The nodemask routines had mixed return values that provided potentially
signed return values that could never happen. This was leading to the
compiler getting confusing about the range of possible return values
(it was thinking things could be negative where they could not be). Fix
all the nodemask routines that should be returning unsigned
(or bool) values. Silences:

 mm/swapfile.c: In function ‘setup_swap_info’:
 mm/swapfile.c:2291:47: error: array subscript -1 is below array bounds of ‘struct plist_node[]’ [-Werror=array-bounds]
  2291 |                                 p->avail_lists[i].prio = 1;
       |                                 ~~~~~~~~~~~~~~^~~
 In file included from mm/swapfile.c:16:
 ./include/linux/swap.h:292:27: note: while referencing ‘avail_lists’
   292 |         struct plist_node avail_lists[]; /*
       |                           ^~~~~~~~~~~

Reported-by: Christophe de Dinechin <dinechin@redhat.com>
Link: https://lore.kernel.org/lkml/20220414150855.2407137-3-dinechin@redhat.com/
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Yury Norov <yury.norov@gmail.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 include/linux/nodemask.h | 38 +++++++++++++++++++-------------------
 lib/nodemask.c           |  4 ++--
 2 files changed, 21 insertions(+), 21 deletions(-)

diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h
index 567c3ddba2c4..2c39663c3407 100644
--- a/include/linux/nodemask.h
+++ b/include/linux/nodemask.h
@@ -42,11 +42,11 @@
  * void nodes_shift_right(dst, src, n)	Shift right
  * void nodes_shift_left(dst, src, n)	Shift left
  *
- * int first_node(mask)			Number lowest set bit, or MAX_NUMNODES
- * int next_node(node, mask)		Next node past 'node', or MAX_NUMNODES
- * int next_node_in(node, mask)		Next node past 'node', or wrap to first,
+ * unsigned int first_node(mask)	Number lowest set bit, or MAX_NUMNODES
+ * unsigend int next_node(node, mask)	Next node past 'node', or MAX_NUMNODES
+ * unsigned int next_node_in(node, mask) Next node past 'node', or wrap to first,
  *					or MAX_NUMNODES
- * int first_unset_node(mask)		First node not set in mask, or 
+ * unsigned int first_unset_node(mask)	First node not set in mask, or
  *					MAX_NUMNODES
  *
  * nodemask_t nodemask_of_node(node)	Return nodemask with bit 'node' set
@@ -153,7 +153,7 @@ static inline void __nodes_clear(nodemask_t *dstp, unsigned int nbits)
 
 #define node_test_and_set(node, nodemask) \
 			__node_test_and_set((node), &(nodemask))
-static inline int __node_test_and_set(int node, nodemask_t *addr)
+static inline bool __node_test_and_set(int node, nodemask_t *addr)
 {
 	return test_and_set_bit(node, addr->bits);
 }
@@ -200,7 +200,7 @@ static inline void __nodes_complement(nodemask_t *dstp,
 
 #define nodes_equal(src1, src2) \
 			__nodes_equal(&(src1), &(src2), MAX_NUMNODES)
-static inline int __nodes_equal(const nodemask_t *src1p,
+static inline bool __nodes_equal(const nodemask_t *src1p,
 					const nodemask_t *src2p, unsigned int nbits)
 {
 	return bitmap_equal(src1p->bits, src2p->bits, nbits);
@@ -208,7 +208,7 @@ static inline int __nodes_equal(const nodemask_t *src1p,
 
 #define nodes_intersects(src1, src2) \
 			__nodes_intersects(&(src1), &(src2), MAX_NUMNODES)
-static inline int __nodes_intersects(const nodemask_t *src1p,
+static inline bool __nodes_intersects(const nodemask_t *src1p,
 					const nodemask_t *src2p, unsigned int nbits)
 {
 	return bitmap_intersects(src1p->bits, src2p->bits, nbits);
@@ -216,20 +216,20 @@ static inline int __nodes_intersects(const nodemask_t *src1p,
 
 #define nodes_subset(src1, src2) \
 			__nodes_subset(&(src1), &(src2), MAX_NUMNODES)
-static inline int __nodes_subset(const nodemask_t *src1p,
+static inline bool __nodes_subset(const nodemask_t *src1p,
 					const nodemask_t *src2p, unsigned int nbits)
 {
 	return bitmap_subset(src1p->bits, src2p->bits, nbits);
 }
 
 #define nodes_empty(src) __nodes_empty(&(src), MAX_NUMNODES)
-static inline int __nodes_empty(const nodemask_t *srcp, unsigned int nbits)
+static inline bool __nodes_empty(const nodemask_t *srcp, unsigned int nbits)
 {
 	return bitmap_empty(srcp->bits, nbits);
 }
 
 #define nodes_full(nodemask) __nodes_full(&(nodemask), MAX_NUMNODES)
-static inline int __nodes_full(const nodemask_t *srcp, unsigned int nbits)
+static inline bool __nodes_full(const nodemask_t *srcp, unsigned int nbits)
 {
 	return bitmap_full(srcp->bits, nbits);
 }
@@ -260,15 +260,15 @@ static inline void __nodes_shift_left(nodemask_t *dstp,
           > MAX_NUMNODES, then the silly min_ts could be dropped. */
 
 #define first_node(src) __first_node(&(src))
-static inline int __first_node(const nodemask_t *srcp)
+static inline unsigned int __first_node(const nodemask_t *srcp)
 {
-	return min_t(int, MAX_NUMNODES, find_first_bit(srcp->bits, MAX_NUMNODES));
+	return min_t(unsigned int, MAX_NUMNODES, find_first_bit(srcp->bits, MAX_NUMNODES));
 }
 
 #define next_node(n, src) __next_node((n), &(src))
-static inline int __next_node(int n, const nodemask_t *srcp)
+static inline unsigned int __next_node(int n, const nodemask_t *srcp)
 {
-	return min_t(int,MAX_NUMNODES,find_next_bit(srcp->bits, MAX_NUMNODES, n+1));
+	return min_t(unsigned int, MAX_NUMNODES, find_next_bit(srcp->bits, MAX_NUMNODES, n+1));
 }
 
 /*
@@ -276,7 +276,7 @@ static inline int __next_node(int n, const nodemask_t *srcp)
  * the first node in src if needed.  Returns MAX_NUMNODES if src is empty.
  */
 #define next_node_in(n, src) __next_node_in((n), &(src))
-int __next_node_in(int node, const nodemask_t *srcp);
+unsigned int __next_node_in(int node, const nodemask_t *srcp);
 
 static inline void init_nodemask_of_node(nodemask_t *mask, int node)
 {
@@ -296,9 +296,9 @@ static inline void init_nodemask_of_node(nodemask_t *mask, int node)
 })
 
 #define first_unset_node(mask) __first_unset_node(&(mask))
-static inline int __first_unset_node(const nodemask_t *maskp)
+static inline unsigned int __first_unset_node(const nodemask_t *maskp)
 {
-	return min_t(int,MAX_NUMNODES,
+	return min_t(unsigned int, MAX_NUMNODES,
 			find_first_zero_bit(maskp->bits, MAX_NUMNODES));
 }
 
@@ -436,11 +436,11 @@ static inline int num_node_state(enum node_states state)
 
 #define first_online_node	first_node(node_states[N_ONLINE])
 #define first_memory_node	first_node(node_states[N_MEMORY])
-static inline int next_online_node(int nid)
+static inline unsigned int next_online_node(int nid)
 {
 	return next_node(nid, node_states[N_ONLINE]);
 }
-static inline int next_memory_node(int nid)
+static inline unsigned int next_memory_node(int nid)
 {
 	return next_node(nid, node_states[N_MEMORY]);
 }
diff --git a/lib/nodemask.c b/lib/nodemask.c
index 3aa454c54c0d..e22647f5181b 100644
--- a/lib/nodemask.c
+++ b/lib/nodemask.c
@@ -3,9 +3,9 @@
 #include <linux/module.h>
 #include <linux/random.h>
 
-int __next_node_in(int node, const nodemask_t *srcp)
+unsigned int __next_node_in(int node, const nodemask_t *srcp)
 {
-	int ret = __next_node(node, srcp);
+	unsigned int ret = __next_node(node, srcp);
 
 	if (ret == MAX_NUMNODES)
 		ret = __first_node(srcp);
-- 
2.32.0


^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH v3 0/2] bitmap: Fix return values to be unsigned
  2022-05-18 20:52 [PATCH v3 0/2] bitmap: Fix return values to be unsigned Kees Cook
  2022-05-18 20:52 ` [PATCH v3 1/2] " Kees Cook
  2022-05-18 20:52 ` [PATCH v3 2/2] nodemask: " Kees Cook
@ 2022-05-18 21:55 ` Yury Norov
  2 siblings, 0 replies; 4+ messages in thread
From: Yury Norov @ 2022-05-18 21:55 UTC (permalink / raw)
  To: Kees Cook
  Cc: Christophe de Dinechin, Rasmus Villemoes, Alexey Dobriyan,
	Andy Shevchenko, Andrew Morton, Zhen Lei, linux-kernel,
	linux-hardening

On Wed, May 18, 2022 at 01:52:21PM -0700, Kees Cook wrote:
> Hi,
> 
> v1: https://lore.kernel.org/lkml/20220517035411.31144-1-keescook@chromium.org
> v2: https://lore.kernel.org/lkml/20220517212234.868181-1-keescook@chromium.org
> v3:
>  - Update missed int variable to unsigned int
>  - Update tools/ bitmaps code to match
>  - Adjust whitespace a bit
> 
> Rationale repeated from the last patch:
> 
> Both nodemask and bitmap routines had mixed return values that provided
> potentially signed results that could never happen. This was leading to
> the compiler getting confusing about the range of possible return values
> (it was thinking things could be negative where they could not be). Fix
> all the nodemask and bitmap routines that should be returning unsigned
> (or bool) values. Silences GCC 12 warnings:
> 
>  mm/swapfile.c: In function ‘setup_swap_info’:
>  mm/swapfile.c:2291:47: error: array subscript -1 is below array bounds of ‘struct plist_node[]’ [-Werror=array-bounds]
>   2291 |                                 p->avail_lists[i].prio = 1;
>        |                                 ~~~~~~~~~~~~~~^~~
>  In file included from mm/swapfile.c:16:
>  ./include/linux/swap.h:292:27: note: while referencing ‘avail_lists’
>    292 |         struct plist_node avail_lists[]; /*
>        |                           ^~~~~~~~~~~
> 
> 
> I note that Alexey and Rasmus have touched on this area in the past,
> fixing up node ids to be unsigned:
> 
> ce0725f78a56 ("numa: make "nr_online_nodes" unsigned int")
> b9726c26dc21 ("numa: make "nr_node_ids" unsigned int")
> 33c4fa8c6763 ("linux/nodemask.h: update bitmap wrappers to take unsigned int")
> 
> -Kees
> 
> 
> Kees Cook (2):
>   bitmap: Fix return values to be unsigned
>   nodemask: Fix return values to be unsigned

Applied on https://github.com/norov/linux.git : bitmap-for-next.
Thanks!

>  include/linux/bitmap.h       | 25 ++++++++++++------------
>  include/linux/nodemask.h     | 38 ++++++++++++++++++------------------
>  lib/bitmap.c                 | 30 ++++++++++++++--------------
>  lib/nodemask.c               |  4 ++--
>  tools/include/linux/bitmap.h | 17 ++++++++--------
>  tools/lib/bitmap.c           | 20 +++++++++----------
>  6 files changed, 68 insertions(+), 66 deletions(-)
> 
> -- 
> 2.32.0

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2022-05-18 22:03 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-05-18 20:52 [PATCH v3 0/2] bitmap: Fix return values to be unsigned Kees Cook
2022-05-18 20:52 ` [PATCH v3 1/2] " Kees Cook
2022-05-18 20:52 ` [PATCH v3 2/2] nodemask: " Kees Cook
2022-05-18 21:55 ` [PATCH v3 0/2] bitmap: " Yury Norov

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