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[cc_fuzz] Collect shared deps by name, not by module.

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cc_fuzz relies on an invariant that's not exactly true. We assume that
for each fuzz target, we'll only have a dependency on a single sanitized
variant of a shared library. In a few instances, this is proven not to
be true, as we end up with a transitive dependency on a shared library
with sanitizer coverage instrumentation, and one without sancov.

This results in breaking the packaging for some fuzz targets. This then
goes on to break `make haiku` in some scenarios.

While this isn't a completely technically correct solution (as we
basically resolve one of the sanitized variants pseduorandomly), it does
resolve the issue for now. Realistically, we should select *both* of
them, and set the DT_RUNPATHS on the shared libraries to point to the
dependencies that have the sanitization that they're expecting. In
practice - this shouldn't break sancov (we might just silently drop some
coverage) or hwasan (we might just silently drop some hwasanification).

I believe that the walk order of VisitDirectDeps is deterministic, and
as such this shouldn't affect the reproducability of fuzz target builds
(and thus won't blow up the Soong rebuilds). ccross@ or dwillemsen@ can
speak better to this than I can though.

Bug: 148306195
Bug: 151102177
Bug: 155123587
Test: lunch flame_hwasan-userdebug && make haiku
Change-Id: I8d4001d93da33e4e5d21f740beb88a20fcc26e2a
This commit is contained in:
Mitch Phillips
2020-04-27 16:44:58 -07:00
parent 6c2962e458
commit c0b442f8a7
1 changed files with 7 additions and 7 deletions
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14
cc/fuzz.go
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@@ -126,7 +126,7 @@ func (fuzz *fuzzBinary) linkerFlags(ctx ModuleContext, flags Flags) Flags {
func collectAllSharedDependencies(ctx android.SingletonContext, module android.Module) android.Paths {
var fringe []android.Module
seen := make(map[android.Module]bool)
seen := make(map[string]bool)
// Enumerate the first level of dependencies, as we discard all non-library
// modules in the BFS loop below.
@@ -140,15 +140,15 @@ func collectAllSharedDependencies(ctx android.SingletonContext, module android.M
for i := 0; i < len(fringe); i++ {
module := fringe[i]
if seen[module] {
if seen[module.Name()] {
continue
}
seen[module] = true
seen[module.Name()] = true
ccModule := module.(*Module)
sharedLibraries = append(sharedLibraries, ccModule.UnstrippedOutputFile())
ctx.VisitDirectDeps(module, func(dep android.Module) {
if isValidSharedDependency(dep) && !seen[dep] {
if isValidSharedDependency(dep) && !seen[dep.Name()] {
fringe = append(fringe, dep)
}
})
@@ -255,13 +255,13 @@ func (fuzz *fuzzBinary) install(ctx ModuleContext, file android.Path) {
}
// Grab the list of required shared libraries.
seen := make(map[android.Module]bool)
seen := make(map[string]bool)
var sharedLibraries android.Paths
ctx.WalkDeps(func(child, parent android.Module) bool {
if seen[child] {
if seen[child.Name()] {
return false
}
seen[child] = true
seen[child.Name()] = true
if isValidSharedDependency(child) {
sharedLibraries = append(sharedLibraries, child.(*Module).UnstrippedOutputFile())