From: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> To: unlisted-recipients:; (no To-header on input) Cc: Nathan Chancellor <natechancellor@gmail.com>, Sakari Ailus <sakari.ailus@linux.intel.com>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, linux-media@vger.kernel.org, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Subject: [PATCH v2 25/41] media: atomisp: Avoid overflow in compute_blending Date: Sat, 30 May 2020 08:55:42 +0200 Message-ID: <22b531f57658727abacb28f534d6fc9d44eee4cf.1590821410.git.mchehab+huawei@kernel.org> (raw) In-Reply-To: <cover.1590821410.git.mchehab+huawei@kernel.org> From: Nathan Chancellor <natechancellor@gmail.com> Clang warns: drivers/staging/media/atomisp/pci/isp/kernels/xnr/xnr_3.0/ia_css_xnr3.host.c:129:35: warning: implicit conversion from 'unsigned long' to 'int32_t' (aka 'int') changes value from 18446744073709543424 to -8192 [-Wconstant-conversion] return MAX(MIN(isp_strength, 0), -XNR_BLENDING_SCALE_FACTOR); ~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~ XNR_BLENDING_SCALE_FACTOR is BIT(13), or 8192, which will easily fit into a signed 32-bit integer. However, it is an unsigned long, which means that negating it is the same as subtracting that value from ULONG_MAX + 1, which causes it to be larger than a signed 32-bit integer so it gets implicitly converted. We can avoid this by using the variable isp_scale, which holds the value of XNR_BLENDING_SCALE_FACTOR already, where the implicit conversion from unsigned long to s32 already happened. If that were to ever overflow, clang would warn: https://godbolt.org/z/EeSxLG Link: https://github.com/ClangBuiltLinux/linux/issues/1036 Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> --- .../atomisp/pci/isp/kernels/xnr/xnr_3.0/ia_css_xnr3.host.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/staging/media/atomisp/pci/isp/kernels/xnr/xnr_3.0/ia_css_xnr3.host.c b/drivers/staging/media/atomisp/pci/isp/kernels/xnr/xnr_3.0/ia_css_xnr3.host.c index a9db6366d20b..629f07faf20a 100644 --- a/drivers/staging/media/atomisp/pci/isp/kernels/xnr/xnr_3.0/ia_css_xnr3.host.c +++ b/drivers/staging/media/atomisp/pci/isp/kernels/xnr/xnr_3.0/ia_css_xnr3.host.c @@ -126,7 +126,7 @@ compute_blending(int strength) * exactly as s0.11 fixed point, but -1.0 can. */ isp_strength = -(((strength * isp_scale) + offset) / host_scale); - return MAX(MIN(isp_strength, 0), -XNR_BLENDING_SCALE_FACTOR); + return MAX(MIN(isp_strength, 0), -isp_scale); } void -- 2.26.2
next prev parent reply other threads:[~2020-05-30 6:58 UTC|newest] Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-05-30 6:55 [PATCH v2 00/41] More atomisp fixes and cleanups Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 01/41] media: atomisp: simplify hive_isp_css_mm_hrt wrapper Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 02/41] media: atomisp: get rid of the hrt/hive_isp_css_mm_hrt abstraction layer Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 03/41] media: atomisp: reduce abstraction at ia_css_memory_access Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 04/41] media: atomisp: go one step further to drop ia_css_memory_access.c Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 05/41] media: atomisp: get rid of mmgr_load and mmgr_store Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 06/41] media: atomisp: get rid of unused memory_realloc code Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 07/41] media: atomisp: change the type returned by mmgr alloc Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 08/41] media: atomisp: get rid of memory_access.c Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 09/41] media: atomisp: hmm_bo: untag user pointers Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 10/41] media: atomisp: add debug message to help debugging hmm code Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 11/41] media: atomisp: use Yocto Aero default hmm pool sizes Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 12/41] media: atomisp: get rid of a warning message Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 13/41] media: atomisp: fix driver caps Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 14/41] media: atomisp: use pin_user_pages() for memory allocation Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 15/41] media: atomisp: add debug for hmm alloc Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 16/41] media: atomisp: improve warning for IRQ enable function Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 17/41] media: atomisp: add debug functions for received events Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 18/41] media: atomisp: add more comments about frame allocation Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 19/41] media: atomisp: remove kvmalloc/kvcalloc abstractions Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 20/41] media: atomisp: avoid OOPS due to non-existing ref_frames Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 21/41] media: atomisp: Clean up if block in sh_css_sp_init_stage Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 22/41] media: atomisp: Remove second increment of count in atomisp_subdev_probe Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 23/41] media: atomisp: Remove unnecessary NULL checks in ia_css_pipe_load_extension Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 24/41] media: atomisp: Remove unnecessary NULL check in atomisp_param Mauro Carvalho Chehab 2020-05-30 6:55 ` Mauro Carvalho Chehab [this message] 2020-05-30 6:55 ` [PATCH v2 26/41] media: atomisp: Remove binary_supports_input_format Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 27/41] media: atomisp: avoid an extra memset() when alloc memory Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 28/41] media: atomisp: remove some trivial wrappers from compat css20 Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 29/41] media: atomisp: do another round of coding style cleanup Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 31/41] media: atomisp: get rid of an error abstraction layer Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 32/41] media: atomisp: don't cause a warn if probe failed Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 33/41] media: atomisp: get rid of a bunch of other wrappers Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 34/41] media: atomisp: get rid of system_types.h Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 35/41] media: atomisp: provide more details about the firmware binaries Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 36/41] media: atomisp: print firmware data during load Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 37/41] media: atomisp: allow passing firmware name at modprobe time Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 38/41] media: atomisp: add a debug message at hmm free Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 39/41] media: atomisp: add some debug messages when binaries are used Mauro Carvalho Chehab 2020-05-30 6:55 ` [PATCH v2 40/41] media: atomisp: get rid of set_fs() dirty hacks Mauro Carvalho Chehab
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