Merge tag 'ffs-const-v6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull ffs const-attribute cleanups from Kees Cook:
 "While working on various hardening refactoring a while back we
  encountered inconsistencies in the application of __attribute_const__
  on the ffs() family of functions.

  This series fixes this across all archs and adds KUnit tests.

  Notably, this found a theoretical underflow in PCI (also fixed here)
  and uncovered an inefficiency in ARC (fixed in the ARC arch PR). I
  kept the series separate from the general hardening PR since it is a
  stand-alone "topic".

   - PCI: Fix theoretical underflow in use of ffs().

   - Universally apply __attribute_const__ to all architecture's
     ffs()-family of functions.

   - Add KUnit tests for ffs() behavior and const-ness"

* tag 'ffs-const-v6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  KUnit: ffs: Validate all the __attribute_const__ annotations
  sparc: Add __attribute_const__ to ffs()-family implementations
  xtensa: Add __attribute_const__ to ffs()-family implementations
  s390: Add __attribute_const__ to ffs()-family implementations
  parisc: Add __attribute_const__ to ffs()-family implementations
  mips: Add __attribute_const__ to ffs()-family implementations
  m68k: Add __attribute_const__ to ffs()-family implementations
  openrisc: Add __attribute_const__ to ffs()-family implementations
  riscv: Add __attribute_const__ to ffs()-family implementations
  hexagon: Add __attribute_const__ to ffs()-family implementations
  alpha: Add __attribute_const__ to ffs()-family implementations
  sh: Add __attribute_const__ to ffs()-family implementations
  powerpc: Add __attribute_const__ to ffs()-family implementations
  x86: Add __attribute_const__ to ffs()-family implementations
  csky: Add __attribute_const__ to ffs()-family implementations
  bitops: Add __attribute_const__ to generic ffs()-family implementations
  KUnit: Introduce ffs()-family tests
  PCI: Test for bit underflow in pcie_set_readrq()

1 files changed, 3 insertions, 3 deletions

diff --git a/arch/parisc/include/asm/bitops.h b/arch/parisc/include/asm/bitops.h
index 0ec9cfc5131f..bd1280a8a5ec 100644
--- a/arch/parisc/include/asm/bitops.h
+++ b/arch/parisc/include/asm/bitops.h
@@ -123,7 +123,7 @@ static __inline__ int test_and_change_bit(int nr, volatile unsigned long * addr)
  * cycles for each mispredicted branch.
  */
 
-static __inline__ unsigned long __ffs(unsigned long x)
+static __inline__ __attribute_const__ unsigned long __ffs(unsigned long x)
 {
 	unsigned long ret;
 
@@ -161,7 +161,7 @@ static __inline__ unsigned long __ffs(unsigned long x)
  * This is defined the same way as the libc and compiler builtin
  * ffs routines, therefore differs in spirit from the above ffz (man ffs).
  */
-static __inline__ int ffs(int x)
+static __inline__ __attribute_const__ int ffs(int x)
 {
 	return x ? (__ffs((unsigned long)x) + 1) : 0;
 }
@@ -171,7 +171,7 @@ static __inline__ int ffs(int x)
  * fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
  */
 
-static __inline__ int fls(unsigned int x)
+static __inline__ __attribute_const__ int fls(unsigned int x)
 {
 	int ret;
 	if (!x)