Fix build warnings and failures (CONFIG_WERROR=y) with a GCC 17 build.
GCC 17 adds -Wconstant-logical-operand which is strict about operands
of && or || that fold to a constant other than 0 or 1.
In the past similar fixes have been done for clang, e.g.
93f56de25937 2017-04-06 mac80211: Fix clang warning about constant operand in
logical operation [v4.12-rc1]
...
dd7fe5d9fd6a 2024-01-17 rtc: max31335: Fix comparison in
max31335_volatile_reg() [v6.8-rc1]
The reason this trips only with gcc is that clang's toggle is more
permissive:
- it checks RHS only, not constant LHS.
- Macros are not checked.
Fix is to effectively make a macro or condition return 0 or 1.
The patches are split up per subsystem and can go independently via
respective trees:
1/4 x86/cpufeatures: the awk-generated *_MASK_BIT_SET() returns 0 or 1.
2/4 wait: ___wait_is_interruptible() with a constant state.
3/4 iommupt: PT_SUPPORTED_FEATURE() in the fvalog2_*() helpers.
4/4 drm/i915: IS_POWER_OF_2() in reg_bits.h, and two Kconfig timeouts.
Tested on x86 defconfig with CONFIG_WERROR=y, at each patch:
- GCC 17 trunk (20261103): each patch removes only its own errors. The
build has no warnings after 4/4.
- GCC 16.1: the build has no warnings. The .text of each object file
does not change. The only differences come from the build timestamp
and the release string.
Vineet Gupta (4):
x86/cpufeatures: Make {REQUIRED,DISABLED}_MASK_BIT_SET() return 0 or 1
wait: Make ___wait_is_interruptible() return 0 or 1
iommupt: Make PT_SUPPORTED_FEATURE() return 0 or 1
drm/i915: Avoid -Wconstant-logical-operand with GCC 17
arch/x86/tools/cpufeaturemasks.awk | 4 ++--
drivers/gpu/drm/i915/gem/i915_gem_context.c | 2 +-
drivers/gpu/drm/i915/i915_config.c | 2 +-
drivers/iommu/generic_pt/pt_defs.h | 2 +-
include/drm/intel/reg_bits.h | 2 +-
include/linux/wait.h | 2 +-
6 files changed, 7 insertions(+), 7 deletions(-)
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2.53.0-Meta
