apex: use proper partition tag for validations

module.PartitionTag(DeviceConfig) doesn't work for validations because
it tells the physical partition where the apex is installed. It returns
"system" even for vendor APEXes when "VendorPath" is set to
"system/vendor".

For validations, we need logical partition tag. So, "vendor:true" apexes
should be "vendor" even when it's installed in /system/vendor.

Bug: 384988749
Test: m --no-skip-soong-tests
Change-Id: Ib478caa62c98808bc94fe350a2f182f1d2b42a46

2 files changed, 46 insertions, 2 deletions

diff --git a/apex/apex_test.go b/apex/apex_test.go
index e1a958268..c123d0300 100644
--- a/apex/apex_test.go
+++ b/apex/apex_test.go
@@ -7090,6 +7090,34 @@ func TestApexAvailable_PrefixMatch(t *testing.T) {
 	`)
 }
 
+func TestApexValidation_UsesProperPartitionTag(t *testing.T) {
+	t.Parallel()
+	ctx := testApex(t, `
+		apex {
+			name: "myapex",
+			key: "myapex.key",
+			updatable: false,
+			vendor: true,
+		}
+		apex_key {
+			name: "myapex.key",
+			public_key: "testkey.avbpubkey",
+			private_key: "testkey.pem",
+		}
+	`, android.FixtureModifyProductVariables(func(variables android.FixtureProductVariables) {
+		// vendor path should not affect "partition tag"
+		variables.VendorPath = proptools.StringPtr("system/vendor")
+	}))
+
+	module := ctx.ModuleForTests("myapex", "android_common_myapex")
+	android.AssertStringEquals(t, "partition tag for host_apex_verifier",
+		"vendor",
+		module.Output("host_apex_verifier.timestamp").Args["partition_tag"])
+	android.AssertStringEquals(t, "partition tag for apex_sepolicy_tests",
+		"vendor",
+		module.Output("apex_sepolicy_tests.timestamp").Args["partition_tag"])
+}
+
 func TestApexValidation_TestApexCanSkipInitRcCheck(t *testing.T) {
 	t.Parallel()
 	ctx := testApex(t, `
diff --git a/apex/builder.go b/apex/builder.go
index d9348c562..daba6f19f 100644
--- a/apex/builder.go
+++ b/apex/builder.go
@@ -1202,6 +1202,22 @@ func runApexLinkerconfigValidation(ctx android.ModuleContext, apexFile android.P
 	return timestamp
 }
 
+// Can't use PartitionTag() because PartitionTag() returns the partition this module is actually
+// installed (e.g. PartitionTag() may return "system" for vendor apex when vendor is linked to /system/vendor)
+func (a *apexBundle) partition() string {
+	if a.SocSpecific() {
+		return "vendor"
+	} else if a.DeviceSpecific() {
+		return "odm"
+	} else if a.ProductSpecific() {
+		return "product"
+	} else if a.SystemExtSpecific() {
+		return "system_ext"
+	} else {
+		return "system"
+	}
+}
+
 // Runs apex_sepolicy_tests
 //
 // $ apex-ls -Z {apex_file} > {file_contexts}
@@ -1213,7 +1229,7 @@ func runApexSepolicyTests(ctx android.ModuleContext, a *apexBundle, apexFile and
 		Input:  apexFile,
 		Output: timestamp,
 		Args: map[string]string{
-			"partition_tag": a.PartitionTag(ctx.DeviceConfig()),
+			"partition_tag": a.partition(),
 		},
 	})
 	return timestamp
@@ -1240,7 +1256,7 @@ func runApexHostVerifier(ctx android.ModuleContext, a *apexBundle, apexFile andr
 		Input:  apexFile,
 		Output: timestamp,
 		Args: map[string]string{
-			"partition_tag": a.PartitionTag(ctx.DeviceConfig()),
+			"partition_tag": a.partition(),
 		},
 	})
 	return timestamp