[PATCH] fls: Change parameter to unsigned int

From: Matthew Wilcox
Date: Mon Nov 05 2018 - 17:11:25 EST

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When testing in userspace, UBSAN pointed out that shifting into the sign
bit is undefined behaviour. It doesn't really make sense to ask for the
highest set bit of a negative value, so just turn the argument type into
an unsigned int.

Some architectures (eg ppc) already had it declared as an unsigned int,
so I don't expect too many problems.

Signed-off-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
---
arch/alpha/include/asm/bitops.h | 4 ++--
arch/arc/include/asm/bitops.h | 4 ++--
arch/c6x/include/asm/bitops.h | 2 +-
arch/csky/include/asm/bitops.h | 2 +-
arch/hexagon/include/asm/bitops.h | 2 +-
arch/ia64/include/asm/bitops.h | 3 +--
arch/m68k/include/asm/bitops.h | 2 +-
arch/mips/include/asm/bitops.h | 2 +-
arch/openrisc/include/asm/bitops/fls.h | 2 +-
arch/parisc/include/asm/bitops.h | 2 +-
arch/s390/include/asm/bitops.h | 4 ++--
arch/unicore32/include/asm/bitops.h | 2 +-
arch/x86/include/asm/bitops.h | 2 +-
include/asm-generic/bitops/builtin-fls.h | 2 +-
include/asm-generic/bitops/fls.h | 2 +-
tools/include/asm-generic/bitops/fls.h | 2 +-
16 files changed, 19 insertions(+), 20 deletions(-)

diff --git a/arch/alpha/include/asm/bitops.h b/arch/alpha/include/asm/bitops.h
index ca43f4d0b937..5adca78830b5 100644
--- a/arch/alpha/include/asm/bitops.h
+++ b/arch/alpha/include/asm/bitops.h
@@ -391,9 +391,9 @@ static inline unsigned long __fls(unsigned long x)
return fls64(x) - 1;
}

-static inline int fls(int x)
+static inline int fls(unsigned int x)
{
- return fls64((unsigned int) x);
+ return fls64(x);
}

/*
diff --git a/arch/arc/include/asm/bitops.h b/arch/arc/include/asm/bitops.h
index 8da87feec59a..ee9246184033 100644
--- a/arch/arc/include/asm/bitops.h
+++ b/arch/arc/include/asm/bitops.h
@@ -278,7 +278,7 @@ static inline __attribute__ ((const)) int clz(unsigned int x)
return res;
}

-static inline int constant_fls(int x)
+static inline int constant_fls(unsigned int x)
{
int r = 32;

@@ -312,7 +312,7 @@ static inline int constant_fls(int x)
* @result: [1-32]
* fls(1) = 1, fls(0x80000000) = 32, fls(0) = 0
*/
-static inline __attribute__ ((const)) int fls(unsigned long x)
+static inline __attribute__ ((const)) int fls(unsigned int x)
{
if (__builtin_constant_p(x))
return constant_fls(x);
diff --git a/arch/c6x/include/asm/bitops.h b/arch/c6x/include/asm/bitops.h
index f0ab012401b6..8b68234ace18 100644
--- a/arch/c6x/include/asm/bitops.h
+++ b/arch/c6x/include/asm/bitops.h
@@ -54,7 +54,7 @@ static inline unsigned long __ffs(unsigned long x)
* This is defined the same way as ffs.
* Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
*/
-static inline int fls(int x)
+static inline int fls(unsigned int x)
{
if (!x)
return 0;
diff --git a/arch/csky/include/asm/bitops.h b/arch/csky/include/asm/bitops.h
index 335f2883fb1e..43b9838bff63 100644
--- a/arch/csky/include/asm/bitops.h
+++ b/arch/csky/include/asm/bitops.h
@@ -40,7 +40,7 @@ static __always_inline unsigned long __ffs(unsigned long x)
/*
* asm-generic/bitops/fls.h
*/
-static __always_inline int fls(int x)
+static __always_inline int fls(unsigned int x)
{
asm volatile(
"ff1 %0\n"
diff --git a/arch/hexagon/include/asm/bitops.h b/arch/hexagon/include/asm/bitops.h
index 2691a1857d20..bee974262387 100644
--- a/arch/hexagon/include/asm/bitops.h
+++ b/arch/hexagon/include/asm/bitops.h
@@ -211,7 +211,7 @@ static inline long ffz(int x)
* This is defined the same way as ffs.
* Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
*/
-static inline int fls(int x)
+static inline int fls(unsigned int x)
{
int r;

diff --git a/arch/ia64/include/asm/bitops.h b/arch/ia64/include/asm/bitops.h
index 56a774bf13fa..2f24ee6459d2 100644
--- a/arch/ia64/include/asm/bitops.h
+++ b/arch/ia64/include/asm/bitops.h
@@ -388,8 +388,7 @@ ia64_fls (unsigned long x)
* Find the last (most significant) bit set. Returns 0 for x==0 and
* bits are numbered from 1..32 (e.g., fls(9) == 4).
*/
-static inline int
-fls (int t)
+static inline int fls(unsigned int t)
{
unsigned long x = t & 0xffffffffu;

diff --git a/arch/m68k/include/asm/bitops.h b/arch/m68k/include/asm/bitops.h
index d979f38af751..10133a968c8e 100644
--- a/arch/m68k/include/asm/bitops.h
+++ b/arch/m68k/include/asm/bitops.h
@@ -502,7 +502,7 @@ static inline unsigned long __ffs(unsigned long x)
/*
* fls: find last bit set.
*/
-static inline int fls(int x)
+static inline int fls(unsigned int x)
{
int cnt;

diff --git a/arch/mips/include/asm/bitops.h b/arch/mips/include/asm/bitops.h
index da1b8718861e..997263921a26 100644
--- a/arch/mips/include/asm/bitops.h
+++ b/arch/mips/include/asm/bitops.h
@@ -541,7 +541,7 @@ static inline unsigned long __ffs(unsigned long word)
* This is defined the same way as ffs.
* Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
*/
-static inline int fls(int x)
+static inline int fls(unsigned int x)
{
int r;

diff --git a/arch/openrisc/include/asm/bitops/fls.h b/arch/openrisc/include/asm/bitops/fls.h
index 9efbf9ad86c4..57de5a1115bf 100644
--- a/arch/openrisc/include/asm/bitops/fls.h
+++ b/arch/openrisc/include/asm/bitops/fls.h
@@ -15,7 +15,7 @@

#ifdef CONFIG_OPENRISC_HAVE_INST_FL1

-static inline int fls(int x)
+static inline int fls(unsigned int x)
{
int ret;

diff --git a/arch/parisc/include/asm/bitops.h b/arch/parisc/include/asm/bitops.h
index 53252d4f9a57..a09eaebfdfd0 100644
--- a/arch/parisc/include/asm/bitops.h
+++ b/arch/parisc/include/asm/bitops.h
@@ -188,7 +188,7 @@ static __inline__ int ffs(int x)
* fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
*/

-static __inline__ int fls(int x)
+static __inline__ int fls(unsigned int x)
{
int ret;
if (!x)
diff --git a/arch/s390/include/asm/bitops.h b/arch/s390/include/asm/bitops.h
index 86e5b2fdee3c..d1f8a4d94cca 100644
--- a/arch/s390/include/asm/bitops.h
+++ b/arch/s390/include/asm/bitops.h
@@ -397,9 +397,9 @@ static inline int fls64(unsigned long word)
* This is defined the same way as ffs.
* Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
*/
-static inline int fls(int word)
+static inline int fls(unsigned int word)
{
- return fls64((unsigned int)word);
+ return fls64(word);
}

#else /* CONFIG_HAVE_MARCH_Z9_109_FEATURES */
diff --git a/arch/unicore32/include/asm/bitops.h b/arch/unicore32/include/asm/bitops.h
index c0cbdbe17168..de5853761c22 100644
--- a/arch/unicore32/include/asm/bitops.h
+++ b/arch/unicore32/include/asm/bitops.h
@@ -22,7 +22,7 @@
* the cntlz instruction for much better code efficiency.
*/

-static inline int fls(int x)
+static inline int fls(unsigned int x)
{
int ret;

diff --git a/arch/x86/include/asm/bitops.h b/arch/x86/include/asm/bitops.h
index 124f9195eb3e..ad7b210aa3f6 100644
--- a/arch/x86/include/asm/bitops.h
+++ b/arch/x86/include/asm/bitops.h
@@ -448,7 +448,7 @@ static __always_inline int ffs(int x)
* set bit if value is nonzero. The last (most significant) bit is
* at position 32.
*/
-static __always_inline int fls(int x)
+static __always_inline int fls(unsigned int x)
{
int r;

diff --git a/include/asm-generic/bitops/builtin-fls.h b/include/asm-generic/bitops/builtin-fls.h
index 62daf940989d..c8455cc28841 100644
--- a/include/asm-generic/bitops/builtin-fls.h
+++ b/include/asm-generic/bitops/builtin-fls.h
@@ -9,7 +9,7 @@
* This is defined the same way as ffs.
* Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
*/
-static __always_inline int fls(int x)
+static __always_inline int fls(unsigned int x)
{
return x ? sizeof(x) * 8 - __builtin_clz(x) : 0;
}
diff --git a/include/asm-generic/bitops/fls.h b/include/asm-generic/bitops/fls.h
index 753aecaab641..b168bb10e1be 100644
--- a/include/asm-generic/bitops/fls.h
+++ b/include/asm-generic/bitops/fls.h
@@ -10,7 +10,7 @@
* Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
*/

-static __always_inline int fls(int x)
+static __always_inline int fls(unsigned int x)
{
int r = 32;

diff --git a/tools/include/asm-generic/bitops/fls.h b/tools/include/asm-generic/bitops/fls.h
index 753aecaab641..b168bb10e1be 100644
--- a/tools/include/asm-generic/bitops/fls.h
+++ b/tools/include/asm-generic/bitops/fls.h
@@ -10,7 +10,7 @@
* Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
*/

-static __always_inline int fls(int x)
+static __always_inline int fls(unsigned int x)
{
int r = 32;

--
2.19.1

Next message: Arend van Spriel: "Re: [PATCH v2 3/3] b43: Use cordic algorithm from kernel library"
Previous message: Doug Smythies: "RE: [RFC/RFT][PATCH v2] cpuidle: New timer events oriented governor for tickless systems"
Next in thread: Thomas Gleixner: "Re: [PATCH] fls: Change parameter to unsigned int"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]