diff options
Diffstat (limited to 'pkg/vcs/linux.go')
| -rw-r--r-- | pkg/vcs/linux.go | 80 |
1 files changed, 56 insertions, 24 deletions
diff --git a/pkg/vcs/linux.go b/pkg/vcs/linux.go index d2371ca5c..8ee801430 100644 --- a/pkg/vcs/linux.go +++ b/pkg/vcs/linux.go @@ -42,32 +42,43 @@ func newLinux(dir string, opts []RepoOpt, vmType string) *linux { } } -func (ctx *linux) PreviousReleaseTags(commit string) ([]string, error) { +func (ctx *linux) PreviousReleaseTags(commit, bisectCompiler string) ([]string, error) { tags, err := ctx.git.previousReleaseTags(commit, false, false, false) if err != nil { return nil, err } + + cutoff := "" + if bisectCompiler == "gcc" { + // Initially we tried to stop at 3.8 because: + // v3.8 does not work with modern perl, and as we go further in history + // make stops to work, then binutils, glibc, etc. So we stop at v3.8. + // Up to that point we only need an ancient gcc. + // + // But kernels don't boot starting from 4.0 and back. + // That was fixed by 99124e4db5b7b70daeaaf1d88a6a8078a0004c6e, + // and it can be cherry-picked into 3.14..4.0 but it conflicts for 3.13 and older. + // + // But starting from 4.0 our user-space binaries start crashing with + // assorted errors which suggests process memory corruption by kernel. + // + // We used to use 4.1 as the oldest tested release (it works in general). + // However, there is correlation between how far back we go and probability + // of getting correct result (see #1532). So we now stop at 4.6. + // 4.6 is somewhat arbitrary, we've seen lots of wrong results in 4.5..4.6 range, + // but there is definitive reason for 4.6. Most likely later we want to bump it + // even more (as new releases are produced). Next good candidate may be 4.11 + // because then we won't need gcc 5.5. + cutoff = "v4.5" + } else if bisectCompiler == "clang" { + // v5.3 was the first release with solid clang support, however I was able to + // compile v5.1..v5.3 using a newer defconfig + make oldconfig. Everything older + // would require further cherry-picks. + cutoff = "v5.2" + } + for i, tag := range tags { - if tag == "v4.5" { - // Initially we tried to stop at 3.8 because: - // v3.8 does not work with modern perl, and as we go further in history - // make stops to work, then binutils, glibc, etc. So we stop at v3.8. - // Up to that point we only need an ancient gcc. - // - // But kernels don't boot starting from 4.0 and back. - // That was fixed by 99124e4db5b7b70daeaaf1d88a6a8078a0004c6e, - // and it can be cherry-picked into 3.14..4.0 but it conflicts for 3.13 and older. - // - // But starting from 4.0 our user-space binaries start crashing with - // assorted errors which suggests process memory corruption by kernel. - // - // We used to use 4.1 as the oldest tested release (it works in general). - // However, there is correlation between how far back we go and probability - // of getting correct result (see #1532). So we now stop at 4.6. - // 4.6 is somewhat arbitrary, we've seen lots of wrong results in 4.5..4.6 range, - // but there is definitive reason for 4.6. Most likely later we want to bump it - // even more (as new releases are produced). Next good candidate may be 4.11 - // because then we won't need gcc 5.5. + if tag == cutoff { tags = tags[:i] break } @@ -121,7 +132,7 @@ func gitReleaseTagToInt(tag string, includeRC bool) uint64 { return v1*1e9 + v2*1e6 + rc*1e3 + v3 } -func (ctx *linux) EnvForCommit(binDir, commit string, kernelConfig []byte) (*BisectEnv, error) { +func (ctx *linux) EnvForCommit(bisectCompiler, binDir, commit string, kernelConfig []byte) (*BisectEnv, error) { tagList, err := ctx.previousReleaseTags(commit, true, false, false) if err != nil { return nil, err @@ -135,8 +146,18 @@ func (ctx *linux) EnvForCommit(binDir, commit string, kernelConfig []byte) (*Bis return nil, err } linuxAlterConfigs(cf, tags) + + compiler := "" + if bisectCompiler == "gcc" { + compiler = filepath.Join(binDir, "gcc-"+linuxGCCVersion(tags), "bin", "gcc") + } else if bisectCompiler == "clang" { + compiler = filepath.Join(binDir, "llvm-"+linuxClangVersion(tags), "bin", "clang") + } else { + return nil, fmt.Errorf("unsupported bisect compiler: %v", bisectCompiler) + } + env := &BisectEnv{ - Compiler: filepath.Join(binDir, "gcc-"+linuxCompilerVersion(tags), "bin", "gcc"), + Compiler: compiler, KernelConfig: cf.Serialize(), } @@ -159,7 +180,18 @@ func (ctx *linux) EnvForCommit(binDir, commit string, kernelConfig []byte) (*Bis return env, nil } -func linuxCompilerVersion(tags map[string]bool) string { +func linuxClangVersion(tags map[string]bool) string { + switch { + case tags["v5.9"]: + return "14.0.6" + default: + // everything before v5.3 might not work great + // everything before v5.1 does not work + return "9.0.1" + } +} + +func linuxGCCVersion(tags map[string]bool) string { switch { case tags["v5.9"]: return "10.1.0" |