pkg/vcs: move linuxAlterConfigs() to separate file

The new linux_configs.go file will contain routines that manage
Linux-related configs.

1 files changed, 3 insertions, 82 deletions

diff --git a/pkg/vcs/linux.go b/pkg/vcs/linux.go
index b29e11664..07278e83f 100644
--- a/pkg/vcs/linux.go
+++ b/pkg/vcs/linux.go
@@ -151,7 +151,7 @@ func (ctx *linux) EnvForCommit(
 	if err != nil {
 		return nil, err
 	}
-	linuxAlterConfigs(cf, tags)
+	setLinuxTagConfigs(cf, tags)
 
 	compiler := ""
 	if compilerType == "gcc" {
@@ -219,85 +219,6 @@ func linuxGCCPath(tags map[string]bool, binDir, defaultCompiler string) string {
 	return filepath.Join(binDir, "gcc-"+version, "bin", "gcc")
 }
 
-func linuxAlterConfigs(cf *kconfig.ConfigFile, tags map[string]bool) {
-	const disableAlways = "disable-always"
-	// If tags is nil, disable only configs marked as disableAlways.
-	checkTag := func(tag string) bool {
-		return tags != nil && !tags[tag] ||
-			tags == nil && tag == disableAlways
-	}
-	disable := map[string]string{
-		// 5.2 has CONFIG_SECURITY_TOMOYO_INSECURE_BUILTIN_SETTING which allows to test tomoyo better.
-		// This config also enables CONFIG_SECURITY_TOMOYO_OMIT_USERSPACE_LOADER
-		// but we need it disabled to boot older kernels.
-		"SECURITY_TOMOYO_OMIT_USERSPACE_LOADER": "v5.2",
-		// Kernel is boot broken before 4.15 due to double-free in vudc_probe:
-		// https://lkml.org/lkml/2018/9/7/648
-		// Fixed by e28fd56ad5273be67d0fae5bedc7e1680e729952.
-		"USBIP_VUDC": "v4.15",
-		// CONFIG_CAN causes:
-		// all runs: crashed: INFO: trying to register non-static key in can_notifier
-		// for v4.11..v4.12 and v4.12..v4.13 ranges.
-		// Fixed by 74b7b490886852582d986a33443c2ffa50970169.
-		"CAN": "v4.13",
-		// Setup of network devices is broken before v4.12 with a "WARNING in hsr_get_node".
-		// Fixed by 675c8da049fd6556eb2d6cdd745fe812752f07a8.
-		"HSR": "v4.12",
-		// Setup of network devices is broken before v4.12 with a "WARNING: ODEBUG bug in __sk_destruct"
-		// coming from smc_release.
-		"SMC": "v4.12",
-		// Kernel is boot broken before 4.10 with a lockdep warning in vhci_hcd_probe.
-		"USBIP_VHCI_HCD": "v4.10",
-		"BT_HCIVHCI":     "v4.10",
-		// Setup of network devices is broken before v4.7 with a deadlock involving team.
-		"NET_TEAM": "v4.7",
-		// Setup of network devices is broken before v4.5 with a warning in batadv_tvlv_container_remove.
-		"BATMAN_ADV": "v4.5",
-		// UBSAN is broken in multiple ways before v5.3, see:
-		// https://github.com/google/syzkaller/issues/1523#issuecomment-696514105
-		"UBSAN": "v5.3",
-		// First, we disable coverage in pkg/bisect because it fails machine testing starting from 4.7.
-		// Second, at 6689da155bdcd17abfe4d3a8b1e245d9ed4b5f2c CONFIG_KCOV selects CONFIG_GCC_PLUGIN_SANCOV
-		// (why?), which is build broken for hundreds of revisions.
-		"KCOV": disableAlways,
-		// This helps to produce stable binaries in presence of kernel tag changes.
-		"LOCALVERSION_AUTO": disableAlways,
-		// BTF fails lots of builds with:
-		// pahole version v1.9 is too old, need at least v1.13
-		// Failed to generate BTF for vmlinux. Try to disable CONFIG_DEBUG_INFO_BTF.
-		"DEBUG_INFO_BTF": disableAlways,
-		// This config only adds debug output. It should not be enabled at all,
-		// but it was accidentially enabled on some instances for some periods of time,
-		// and kernel is boot-broken for prolonged ranges of commits with deadlock
-		// which makes bisections take weeks.
-		"DEBUG_KOBJECT": disableAlways,
-		// This config is causing problems to kernel signature calculation as new initramfs is generated
-		// as a part of every build. Due to this init.data section containing this generated initramfs
-		// is differing between builds causing signture being random number.
-		"BLK_DEV_INITRD": disableAlways,
-	}
-	for cfg, tag := range disable {
-		if checkTag(tag) {
-			cf.Unset(cfg)
-		}
-	}
-	alter := []struct {
-		From string
-		To   string
-		Tag  string
-	}{
-		// Even though ORC unwinder was introduced a long time ago, it might have been broken for
-		// some time. 5.4 is chosen as a version tag, where ORC unwinder seems to work properly.
-		{"UNWINDER_ORC", "UNWINDER_FRAME_POINTER", "v5.4"},
-	}
-	for _, a := range alter {
-		if checkTag(a.Tag) {
-			cf.Unset(a.From)
-			cf.Set(a.To, kconfig.Yes)
-		}
-	}
-}
-
 func (ctx *linux) PrepareBisect() error {
 	if ctx.vmType != "gvisor" {
 		// Some linux repos we fuzz don't import the upstream release git tags. We need tags
@@ -401,8 +322,8 @@ func (ctx *linux) Minimize(target *targets.Target, original, baseline []byte,
 	if err != nil {
 		return nil, err
 	}
-	linuxAlterConfigs(originalConfig, nil)
-	linuxAlterConfigs(baselineConfig, nil)
+	setLinuxTagConfigs(originalConfig, nil)
+	setLinuxTagConfigs(baselineConfig, nil)
 	kconfPred := func(candidate *kconfig.ConfigFile) (bool, error) {
 		res, err := pred(serialize(candidate))
 		return res == BisectBad, err