]> git.baikalelectronics.ru Git - kernel.git/commit
media: m5mols: fix off-by-one loop termination error
authorLinus Torvalds <torvalds@linux-foundation.org>
Fri, 17 Mar 2023 20:51:17 +0000 (13:51 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 22 Mar 2023 12:28:07 +0000 (13:28 +0100)
commit60eec09db015b923549a50c4f2b0fffa05a2d5f1
tree4379dd9c2eb481f57977fdb44599e53ad5ed5748
parent57ee335cb10d96cac5733945093af3f1687090ac
media: m5mols: fix off-by-one loop termination error

[ Upstream commit efbcbb12ee99f750c9f25c873b55ad774871de2a ]

The __find_restype() function loops over the m5mols_default_ffmt[]
array, and the termination condition ends up being wrong: instead of
stopping when the iterator becomes the size of the array it traverses,
it stops after it has already overshot the array.

Now, in practice this doesn't likely matter, because the code will
always find the entry it looks for, and will thus return early and never
hit that last extra iteration.

But it turns out that clang will unroll the loop fully, because it has
only two iterations (well, three due to the off-by-one bug), and then
clang will end up just giving up in the middle of the loop unrolling
when it notices that the code walks past the end of the array.

And that made 'objtool' very unhappy indeed, because the generated code
just falls off the edge of the universe, and ends up falling through to
the next function, causing this warning:

   drivers/media/i2c/m5mols/m5mols.o: warning: objtool: m5mols_set_fmt() falls through to next function m5mols_get_frame_desc()

Fix the loop ending condition.

Reported-by: Jens Axboe <axboe@kernel.dk>
Analyzed-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Analyzed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/linux-block/CAHk-=wgTSdKYbmB1JYM5vmHMcD9J9UZr0mn7BOYM_LudrP+Xvw@mail.gmail.com/
Fixes: f3e08500ecb8 ("[media] Add support for M-5MOLS 8 Mega Pixel camera ISP")
Cc: HeungJun, Kim <riverful.kim@samsung.com>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/media/i2c/m5mols/m5mols_core.c