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| author | Jani Nikula <jani.nikula@intel.com> | 2018-10-16 15:29:37 +0300 |
|---|---|---|
| committer | Jani Nikula <jani.nikula@intel.com> | 2018-10-17 09:55:21 +0300 |
| commit | 7b3e51dd439bead71d9e4504d89a32a8496ac0aa (patch) | |
| tree | df8baa3f474dc96de2c37c8e5f5460d3d0c28970 | |
| parent | 046c9bca3d829d1f67e4667ffeac099564a683a4 (diff) | |
| download | linux-7b3e51dd439bead71d9e4504d89a32a8496ac0aa.tar.xz | |
drm/i915: Ensure _print_param() builds with Clang
When building the kernel with Clang with defconfig and CONFIG_64BIT
disabled, vmlinux fails to link because of the BUILD_BUG in
_print_param.
ld: drivers/gpu/drm/i915/i915_params.o: in function `i915_params_dump':
i915_params.c:(.text+0x56): undefined reference to
`__compiletime_assert_191'
This function is semantically invalid unless the code is first inlined
then constant folded, which doesn't work for Clang because semantic
analysis happens before optimization/inlining.
[The above written by Nathan Chancellor <natechancellor@gmail.com>]
Use WARN_ONCE() instead of BUILD_BUG() to avoid the problem. The
WARN_ONCE() should get optimized away unless there's a type that's not
handled by _print_param().
References: https://github.com/ClangBuiltLinux/linux/issues/191
References: http://mid.mail-archive.com/20181009171401.14980-1-natechancellor@gmail.com
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181016122938.18757-1-jani.nikula@intel.com
| -rw-r--r-- | drivers/gpu/drm/i915/i915_params.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c index bd6bd8879cab..8d71886b5f03 100644 --- a/drivers/gpu/drm/i915/i915_params.c +++ b/drivers/gpu/drm/i915/i915_params.c @@ -184,7 +184,8 @@ static __always_inline void _print_param(struct drm_printer *p, else if (!__builtin_strcmp(type, "char *")) drm_printf(p, "i915.%s=%s\n", name, *(const char **)x); else - BUILD_BUG(); + WARN_ONCE(1, "no printer defined for param type %s (i915.%s)\n", + type, name); } /** |