shader compilation fails on Adreno 420/430

[Johan Vos]

Recently, we see crashes on recent Android devices that use an Adreno 420
or 430 GPU.

It turns out that those crashes occur while performing the native shader
compilation
(Java_com_sun_prism_es2_GLContext_nCompileShader)
The crash really is a segmentation violation, which shouldn't happen

More info is also here:
https://bitbucket.org/javafxports/javafxmobile-plugin/issues/28/lollipop-51-and-error-with-gradient

I managed to isolate the problem: In
the FillRoundRect_LinearGradient_PAD.frag we have this:

vec2 pixcoord = vec2(
    gl_FragCoord.x-jsl_pixCoordOffset.x,

((jsl_pixCoordOffset.z-gl_FragCoord.y)*jsl_pixCoordOffset.w)-jsl_pixCoordOffset.y);

If I replace this into

vec2 pixcoord = vec2(0.5,0.5);

we don't see a crash anymore.
Clearly this is not a solution.

I'm trying to get a clue on what might be wrong, and how we can create a
work-around. Unfortunately, my knowledge on shaders is extremely limited,
so all help is very welcome.

Thanks,

- Johan

fyi, the Android error is added here:

F/libc    (13998): Fatal signal 11 (SIGSEGV), code 1, fault addr 0xc in tid
1402
1 (QuantumRenderer)
I/DEBUG   (  354): *** *** *** *** *** *** *** *** *** *** *** *** *** ***
*** *
**
I/DEBUG   (  354): Build fingerprint:
'google/shamu/shamu:5.1.1/LMY47Z/1860966:u
ser/release-keys'
I/DEBUG   (  354): Revision: '33696'
I/DEBUG   (  354): ABI: 'arm'
I/DEBUG   (  354): pid: 13998, tid: 14021, name: QuantumRenderer  >>>
com.hellog
luon <<<
I/DEBUG   (  354): signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0xc
I/DEBUG   (  354):     r0 00000000  r1 aa9ba96b  r2 00000000  r3 ffffffff
I/DEBUG   (  354):     r4 9f715abc  r5 aec99cf0  r6 9f70f7f8  r7 00000014
I/DEBUG   (  354):     r8 aec99d04  r9 aaaf4b8b  sl ffffffde  fp 9f70fa10
I/DEBUG   (  354):     ip aab235a8  sp 9f70f7e0  lr aaa09205  pc aaa09218
 cpsr
60070030
I/DEBUG   (  354):
I/DEBUG   (  354): backtrace:
I/DEBUG   (  354):     #00 pc 005bb218
 /system/vendor/lib/libllvm-glnext.so (TP
arseContext::handleIdentifier(TSymbol*, llvm::StringRef const&, int)+275)
I/DEBUG   (  354):     #01 pc 005d727d
 /system/vendor/lib/libllvm-glnext.so (yy
2parse(TParseContext&)+972)
I/DEBUG   (  354):     #02 pc 005dcd3d
 /system/vendor/lib/libllvm-glnext.so (yy
2PaYYParse(TParseContext&)+16)
I/DEBUG   (  354):     #03 pc 005e481d
 /system/vendor/lib/libllvm-glnext.so (YY
Parser::ParseStrings(char**, long*, int, TParseContext&, int)+276)
I/DEBUG   (  354):     #04 pc 005b305b
 /system/vendor/lib/libllvm-glnext.so (Sh
Compile+1326)
I/DEBUG   (  354):     #05 pc 00552399
 /system/vendor/lib/libllvm-glnext.so (LL
VMCompiler::parse(QGLC_SRCSHADER*)+1188)
I/DEBUG   (  354):     #06 pc 005557ed
 /system/vendor/lib/libllvm-glnext.so (Co
mpilerContext::CompileToIRShader(QGLC_SRCSHADER*,
QGLC_COMPILETOIR_RESULT*)+168)

I/DEBUG   (  354):     #07 pc 00105903
 /system/vendor/lib/egl/libGLESv2_adreno.
so (EsxShaderCompiler::CompileShader(EsxContext const*, EsxShader const*,
EsxInf
oLog*)+526)
I/DEBUG   (  354):     #08 pc 00103ced
 /system/vendor/lib/egl/libGLESv2_adreno.
so (EsxShader::Compile(EsxContext*)+72)
I/DEBUG   (  354):     #09 pc 000b2201
 /system/vendor/lib/egl/libGLESv2_adreno.
so (EsxContext::GlCompileShader(unsigned int)+60)
I/DEBUG   (  354):     #10 pc 000e4ef9
 /system/vendor/lib/egl/libGLESv2_adreno.
so (EsxGlApiParamValidate::GlCompileShader(EsxDispatch*, unsigned int)+40)
I/DEBUG   (  354):     #11 pc 000a947d
 /system/vendor/lib/egl/libGLESv2_adreno.
so (glCompileShader+44)
I/DEBUG   (  354):     #12 pc 00005431
 /data/app/com.hellogluon-1/lib/arm/libpr
ism_es2_monocle.so (Java_com_sun_prism_es2_GLContext_nCompileShader+112)
I/DEBUG   (  354):     #13 pc 00518ea5  /data/dalvik-cache/arm/data at app
@com.hell
ogluon-1 at base.apk@classes.dex
W/ActivityManager(  804):   Force finishing activity 1
com.hellogluon/javafxport
s.android.FXActivity