From 71218dbc401cbb8f7e052e7a64372d9732082d5d Mon Sep 17 00:00:00 2001 From: Ian Lance Taylor Date: Tue, 21 Jul 2020 21:37:58 -0700 Subject: [PATCH] runtime: don't mlock on Ubuntu 5.4 systems For #35777 For #37436 Fixes #40184 Change-Id: I68561497d9258e994d1c6c48d4fb41ac6130ee3a Reviewed-on: https://go-review.googlesource.com/c/go/+/244059 Run-TryBot: Ian Lance Taylor TryBot-Result: Gobot Gobot Reviewed-by: Austin Clements --- src/runtime/os_linux_x86.go | 35 ++++++++++++++++++++++++++++++++++- 1 file changed, 34 insertions(+), 1 deletion(-) diff --git a/src/runtime/os_linux_x86.go b/src/runtime/os_linux_x86.go index d001e6ee59..97f870707d 100644 --- a/src/runtime/os_linux_x86.go +++ b/src/runtime/os_linux_x86.go @@ -7,7 +7,10 @@ package runtime -import "runtime/internal/atomic" +import ( + "runtime/internal/atomic" + "unsafe" +) //go:noescape func uname(utsname *new_utsname) int @@ -55,6 +58,36 @@ func osArchInit() { return } + if major == 5 && minor == 4 && patch < 2 { + // All 5.4 versions of Ubuntu are patched. + procVersion := []byte("/proc/version\000") + f := open(&procVersion[0], _O_RDONLY, 0) + if f >= 0 { + var buf [512]byte + p := noescape(unsafe.Pointer(&buf[0])) + n := read(f, p, int32(len(buf))) + closefd(f) + + needle := []byte("Ubuntu") + contains: + for i, c := range buf[:n] { + if c != needle[0] { + continue + } + if int(n)-i < len(needle) { + break + } + for j, c2 := range needle { + if c2 != buf[i+j] { + continue contains + } + } + // This is an Ubuntu system. + return + } + } + } + if major == 5 && (minor == 2 || minor == 3 && patch < 15 || minor == 4 && patch < 2) { gsignalInitQuirk = mlockGsignal if m0.gsignal != nil { -- 2.48.1