325609c355
commit 2bac084468847cfe5bbc7166082b2a208514bb1c upstream.
Work for __counted_by on generic pointers in structures (not just
flexible array members) has started landing in Clang 19 (current tip of
tree). During the development of this feature, a restriction was added
to __counted_by to prevent the flexible array member's element type from
including a flexible array member itself such as:
struct foo {
int count;
char buf[];
};
struct bar {
int count;
struct foo data[] __counted_by(count);
};
because the size of data cannot be calculated with the standard array
size formula:
sizeof(struct foo) * count
This restriction was downgraded to a warning but due to CONFIG_WERROR,
it can still break the build. The application of __counted_by on the
states member of 'struct _StateArray' triggers this restriction,
resulting in:
drivers/gpu/drm/radeon/pptable.h:442:5: error: 'counted_by' should not be applied to an array with element of unknown size because 'ATOM_PPLIB_STATE_V2' (aka 'struct _ATOM_PPLIB_STATE_V2') is a struct type with a flexible array member. This will be an error in a future compiler version [-Werror,-Wbounds-safety-counted-by-elt-type-unknown-size]
442 | ATOM_PPLIB_STATE_V2 states[] __counted_by(ucNumEntries);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
Remove this use of __counted_by to fix the warning/error. However,
rather than remove it altogether, leave it commented, as it may be
possible to support this in future compiler releases.
Cc: stable@vger.kernel.org
Closes: https://github.com/ClangBuiltLinux/linux/issues/2028
Fixes: efade6fe50e7 ("drm/radeon: silence UBSAN warning (v3)")
Signed-off-by: Bill Wendling <morbo@google.com>
Co-developed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.