* Re: linux-4.16-rc5/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c:1723]: (warning) Possible null pointer dereference: pipe_ctx [not found] <HE1PR0802MB2331D43DAFA4EDDE964F0CC69CD30@HE1PR0802MB2331.eurprd08.prod.outlook.com> @ 2018-03-12 22:23 ` Andrey Grodzovsky 2018-03-12 23:06 ` Li, Roman 0 siblings, 1 reply; 3+ messages in thread From: Andrey Grodzovsky @ 2018-03-12 22:23 UTC (permalink / raw) To: David Binderman, alexander.deucher, christian.koenig, David1.Zhou, airlied, amd-gfx, dri-devel, linux-kernel, Harry Wentland, Li, Roman On 03/12/2018 06:22 AM, David Binderman wrote: > hello there, > > Source code is > > > for (i = 0; i < dc->res_pool->pipe_count; i++) { > if (res_ctx->pipe_ctx[i].stream) { > pipe_ctx = &res_ctx->pipe_ctx[i]; > *pipe_idx = i; > break; > } > } Indeed something like if (!pipe_ctx) return false; seems the right thing here. Harry, Roman , your opinion ? Andrey > > /* Only supports eDP */ > if (pipe_ctx->stream->sink->link->connector_signal != SIGNAL_TYPE_EDP) > return false; > > Suggest add some code to deal with the case that the for loop doesn't find > what it is looking for and so pipe_ctx is NULL. > > Regards > > David Binderman > > _______________________________________________ > amd-gfx mailing list > amd-gfx@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/amd-gfx ^ permalink raw reply [flat|nested] 3+ messages in thread
* RE: linux-4.16-rc5/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c:1723]: (warning) Possible null pointer dereference: pipe_ctx 2018-03-12 22:23 ` linux-4.16-rc5/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c:1723]: (warning) Possible null pointer dereference: pipe_ctx Andrey Grodzovsky @ 2018-03-12 23:06 ` Li, Roman 2018-03-12 23:10 ` Andrey Grodzovsky 0 siblings, 1 reply; 3+ messages in thread From: Li, Roman @ 2018-03-12 23:06 UTC (permalink / raw) To: Grodzovsky, Andrey, David Binderman, Deucher, Alexander, Koenig, Christian, Zhou, David(ChunMing), airlied, amd-gfx, dri-devel, linux-kernel, Wentland, Harry There is a check just before for-loop that should ensure pipe_ctx is not null: /* Only supports single display */ if (context->stream_count != 1) return false; To remove the subject warning - we can rather add an assert: assert(pipe_ctx); Thanks, Roman -----Original Message----- From: Grodzovsky, Andrey Sent: Monday, March 12, 2018 6:23 PM To: David Binderman <dcb314@hotmail.com>; Deucher, Alexander <Alexander.Deucher@amd.com>; Koenig, Christian <Christian.Koenig@amd.com>; Zhou, David(ChunMing) <David1.Zhou@amd.com>; airlied@linux.ie; amd-gfx@lists.freedesktop.org; dri-devel@lists.freedesktop.org; linux-kernel@vger.kernel.org; Wentland, Harry <Harry.Wentland@amd.com>; Li, Roman <Roman.Li@amd.com> Subject: Re: linux-4.16-rc5/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c:1723]: (warning) Possible null pointer dereference: pipe_ctx On 03/12/2018 06:22 AM, David Binderman wrote: > hello there, > > Source code is > > > for (i = 0; i < dc->res_pool->pipe_count; i++) { > if (res_ctx->pipe_ctx[i].stream) { > pipe_ctx = &res_ctx->pipe_ctx[i]; > *pipe_idx = i; > break; > } > } Indeed something like if (!pipe_ctx) return false; seems the right thing here. Harry, Roman , your opinion ? Andrey > > /* Only supports eDP */ > if (pipe_ctx->stream->sink->link->connector_signal != > SIGNAL_TYPE_EDP) > return false; > > Suggest add some code to deal with the case that the for loop doesn't > find what it is looking for and so pipe_ctx is NULL. > > Regards > > David Binderman > > _______________________________________________ > amd-gfx mailing list > amd-gfx@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/amd-gfx ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: linux-4.16-rc5/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c:1723]: (warning) Possible null pointer dereference: pipe_ctx 2018-03-12 23:06 ` Li, Roman @ 2018-03-12 23:10 ` Andrey Grodzovsky 0 siblings, 0 replies; 3+ messages in thread From: Andrey Grodzovsky @ 2018-03-12 23:10 UTC (permalink / raw) To: Li, Roman, David Binderman, Deucher, Alexander, Koenig, Christian, Zhou, David(ChunMing), airlied, amd-gfx, dri-devel, linux-kernel, Wentland, Harry The check before alone is not enough for a case where there is another bug introduced so that context->stream_count is not in sync with actual number of streams across entire resource_context. At least assert indeed should be there. Andrey On 03/12/2018 07:06 PM, Li, Roman wrote: > There is a check just before for-loop that should ensure pipe_ctx is not null: > > /* Only supports single display */ > if (context->stream_count != 1) > return false; > > To remove the subject warning - we can rather add an assert: > assert(pipe_ctx); > > Thanks, > Roman > > -----Original Message----- > From: Grodzovsky, Andrey > Sent: Monday, March 12, 2018 6:23 PM > To: David Binderman <dcb314@hotmail.com>; Deucher, Alexander <Alexander.Deucher@amd.com>; Koenig, Christian <Christian.Koenig@amd.com>; Zhou, David(ChunMing) <David1.Zhou@amd.com>; airlied@linux.ie; amd-gfx@lists.freedesktop.org; dri-devel@lists.freedesktop.org; linux-kernel@vger.kernel.org; Wentland, Harry <Harry.Wentland@amd.com>; Li, Roman <Roman.Li@amd.com> > Subject: Re: linux-4.16-rc5/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c:1723]: (warning) Possible null pointer dereference: pipe_ctx > > > > On 03/12/2018 06:22 AM, David Binderman wrote: >> hello there, >> >> Source code is >> >> >> for (i = 0; i < dc->res_pool->pipe_count; i++) { >> if (res_ctx->pipe_ctx[i].stream) { >> pipe_ctx = &res_ctx->pipe_ctx[i]; >> *pipe_idx = i; >> break; >> } >> } > Indeed something like > > if (!pipe_ctx) > return false; > > seems the right thing here. > > Harry, Roman , your opinion ? > > Andrey > >> /* Only supports eDP */ >> if (pipe_ctx->stream->sink->link->connector_signal != >> SIGNAL_TYPE_EDP) >> return false; >> >> Suggest add some code to deal with the case that the for loop doesn't >> find what it is looking for and so pipe_ctx is NULL. >> >> Regards >> >> David Binderman >> >> _______________________________________________ >> amd-gfx mailing list >> amd-gfx@lists.freedesktop.org >> https://lists.freedesktop.org/mailman/listinfo/amd-gfx ^ permalink raw reply [flat|nested] 3+ messages in thread
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2018-03-12 22:23 ` linux-4.16-rc5/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c:1723]: (warning) Possible null pointer dereference: pipe_ctx Andrey Grodzovsky
2018-03-12 23:06 ` Li, Roman
2018-03-12 23:10 ` Andrey Grodzovsky
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