Friendly ping regarding this patch :-) --Myles
On Wed, Jun 19, 2013 at 12:47 AM, Myles C. Maxfield < [email protected]> wrote: > Any word on this? > > Thanks, > Myles > > > On Mon, Jun 17, 2013 at 12:09 PM, Myles C. Maxfield < > [email protected]> wrote: > >> Sure. I was under the impression that |size| couldn't be both greater >> than 4 and a non-multiple of 4, but I've reworked the patch to incorporate >> this and to be a little more straightforward. >> >> Is the only way to replace "ASAN" with "Address Sanitizer" to change the >> subject of this email thread? >> >> Anyway, here's a similar but modified patch: >> >> From: Myles C. Maxfield <[email protected]> >> Date: Mon, 17 Jun 2013 11:50:05 -0700 >> Subject: [PATCH] Appeasing Address Sanitizer >> >> --- >> src/mesa/program/prog_parameter.c | 13 ++++++++++++- >> 1 file changed, 12 insertions(+), 1 deletion(-) >> >> diff --git a/src/mesa/program/prog_parameter.c >> b/src/mesa/program/prog_parameter.c >> index 95b153e..1d46476 100644 >> --- a/src/mesa/program/prog_parameter.c >> +++ b/src/mesa/program/prog_parameter.c >> @@ -155,7 +155,18 @@ _mesa_add_parameter(struct gl_program_parameter_list >> *paramList, >> p->Size = size; >> p->DataType = datatype; >> if (values) { >> - COPY_4V(paramList->ParameterValues[oldNum + i], values); >> + if (size >= (i+1)*4) { >> + COPY_4V(paramList->ParameterValues[oldNum + i], values); >> + } else { >> + /* silence asan */ >> + for (j = 0; j < 4; j++) { >> + if (i*4+j < size) { >> + paramList->ParameterValues[oldNum + i][j] = >> values[i*4+j]; >> + } else { >> + paramList->ParameterValues[oldNum + i][j].f = >> 0.0f; >> + } >> + } >> + } >> values += 4; >> p->Initialized = GL_TRUE; >> } >> -- >> 1.7.12.4 (Apple Git-37) >> >> >> On Mon, Jun 17, 2013 at 8:13 AM, Brian Paul <[email protected]> wrote: >> >>> On 06/14/2013 05:12 PM, Myles C. Maxfield wrote: >>> >>>> Sorry for the triple post; I received a bounce email the first time and >>>> got sent to the spam folder the second time, so I'm trying a third time. >>>> >>>> Hello, all. I was running Mesa with Address Sanitizer [1] turned on, >>>> and found one place where ASAN pointed out a read-before-initialized >>>> problem. In particular, in _mesa_add_parameter, in prog_parameter.c, >>>> |values| represents an array holding a variable number of values. These >>>> values get copied out of the array 4 at a time with the COPY_4V macro, >>>> however, the array might only contain a single element. In this case, ASAN >>>> reports a read-before-initialize because the last 3 of the 4 elements >>>> haven't been written to yet. I was hoping to contribute a patch that will >>>> silence this problem that ASAN reports. I'm happy to incorporate any >>>> feedback anyone has into this patch. >>>> >>>> Thanks, >>>> Myles C. Maxfield >>>> >>>> [1]https://code.google.com/p/**address-sanitizer/<https://code.google.com/p/address-sanitizer/> >>>> >>>> diff --git a/src/mesa/program/prog_**parameter.c >>>> b/src/mesa/program/prog_**parameter.c >>>> index 2018fa5..63915fb 100644 >>>> --- a/src/mesa/program/prog_**parameter.c >>>> +++ b/src/mesa/program/prog_**parameter.c >>>> @@ -158,7 +158,17 @@ _mesa_add_parameter(struct >>>> gl_program_parameter_list *paramList, >>>> p->DataType = datatype; >>>> p->Flags = flags; >>>> if (values) { >>>> - COPY_4V(paramList->**ParameterValues[oldNum + i], values); >>>> + if (size & 3) { >>>> + for (j = 0; j < size; j++) { >>>> + paramList->ParameterValues[**oldNum + i][j] = >>>> values[j]; >>>> + } >>>> + /* silence asan */ >>>> + for (j = size; j < 4; j++) { >>>> + paramList->ParameterValues[**oldNum + i][j].f = 0; >>>> + } >>>> + } else { >>>> + COPY_4V(paramList->**ParameterValues[oldNum + i], >>>> values); >>>> + } >>>> values += 4; >>>> p->Initialized = GL_TRUE; >>>> } >>>> >>> >>> The value of 'size' can actually be greater than 4 (IIRC, and the >>> function comment are still correct). For example, for a matrix, size=16. >>> So the first for-loop should be fixed, just to be safe. >>> >>> In the commit message, let's not use "ASAN" since it's not obvious that >>> it means Address Sanitizer. >>> >>> -Brian >>> >>> >>> >>> >> >
_______________________________________________ mesa-dev mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/mesa-dev
