Re: [PATCH v2 11/16] media: sur40: Remove uninitialized_var() usage
From: Nick Desaulniers <hidden>
Date: 2020-06-22 18:39:17
Also in:
linux-block, linux-clk, linux-doc, linux-ide, linux-mm, linux-spi, linux-wireless, lkml
On Fri, Jun 19, 2020 at 8:30 PM Kees Cook [off-list ref] wrote:
Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings (e.g.
"unused variable"). If the compiler thinks it is uninitialized, either
simply initialize the variable or make compiler changes. As a precursor
to removing[2] this[3] macro[4], just remove this variable since it was
actually unused:
drivers/input/touchscreen/sur40.c:459:6: warning: variable 'packet_id' set but not used [-Wunused-but-set-variable]
459 | u32 packet_id;
| ^~~~~~~~~
However, in keeping with the documentation desires outlined in commit
335abaea7a27 ("Input: sur40 - silence unnecessary noisy debug output"),
comment out the assignment instead of removing it.
[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ (local)
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ (local)
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ (local)
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ (local)
Fixes: 335abaea7a27 ("Input: sur40 - silence unnecessary noisy debug output")Probably should comment out `/* u32 packet_id */` rather than removing it then, but that doesn't really matter. Either way, Reviewed-by: Nick Desaulniers <redacted>
quoted hunk ↗ jump to hunk
Signed-off-by: Kees Cook <redacted> --- drivers/input/touchscreen/sur40.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)diff --git a/drivers/input/touchscreen/sur40.c b/drivers/input/touchscreen/sur40.c index 34d31c7ec8ba..620cdd7d214a 100644 --- a/drivers/input/touchscreen/sur40.c +++ b/drivers/input/touchscreen/sur40.c@@ -456,8 +456,6 @@ static void sur40_poll(struct input_dev *input) { struct sur40_state *sur40 = input_get_drvdata(input); int result, bulk_read, need_blobs, packet_blobs, i; - u32 uninitialized_var(packet_id); - struct sur40_header *header = &sur40->bulk_in_buffer->header; struct sur40_blob *inblob = &sur40->bulk_in_buffer->blobs[0];@@ -491,7 +489,7 @@ static void sur40_poll(struct input_dev *input) if (need_blobs == -1) { need_blobs = le16_to_cpu(header->count); dev_dbg(sur40->dev, "need %d blobs\n", need_blobs); - packet_id = le32_to_cpu(header->packet_id); + /* packet_id = le32_to_cpu(header->packet_id); */ } /* --2.25.1 -- You received this message because you are subscribed to the Google Groups "Clang Built Linux" group. To unsubscribe from this group and stop receiving emails from it, send an email to clang-built-linux+unsubscribe@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/clang-built-linux/20200620033007.1444705-12-keescook%40chromium.org.
-- Thanks, ~Nick Desaulniers