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| author | Austin Clements <austin@google.com> | 2020-07-31 15:58:00 -0400 |
|---|---|---|
| committer | Austin Clements <austin@google.com> | 2020-08-13 02:17:17 +0000 |
| commit | 92bda33d2771a9b12868d9025f113538fa7a84de (patch) | |
| tree | e6a177cfe289630c07d32d36b7be7e140d7809a7 /src/runtime/sys_linux_amd64.s | |
| parent | b2353174db1349f15113416b4df2a833db6058a6 (diff) | |
| download | go-92bda33d2771a9b12868d9025f113538fa7a84de.tar.gz go-92bda33d2771a9b12868d9025f113538fa7a84de.zip | |
runtime: revert signal stack mlocking
Go 1.14 included a (rather awful) workaround for a Linux kernel bug
that corrupted vector registers on x86 CPUs during signal delivery
(https://bugzilla.kernel.org/show_bug.cgi?id=205663). This bug was
introduced in Linux 5.2 and fixed in 5.3.15, 5.4.2 and all 5.5 and
later kernels. The fix was also back-ported by major distros. This
workaround was necessary, but had unfortunate downsides, including
causing Go programs to exceed the mlock ulimit in many configurations
(#37436).
We're reasonably confident that by the Go 1.16 release, the number of
systems running affected kernels will be vanishingly small. Hence,
this CL removes this workaround.
This effectively reverts CLs 209597 (version parser), 209899 (mlock
top of signal stack), 210299 (better failure message), 223121 (soft
mlock failure handling), and 244059 (special-case patched Ubuntu
kernels). The one thing we keep is the osArchInit function. It's empty
everywhere now, but is a reasonable hook to have.
Updates #35326, #35777 (the original register corruption bugs).
Updates #40184 (request to revert in 1.15).
Fixes #35979.
Change-Id: Ie213270837095576f1f3ef46bf3de187dc486c50
Reviewed-on: https://go-review.googlesource.com/c/go/+/246200
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Diffstat (limited to 'src/runtime/sys_linux_amd64.s')
| -rw-r--r-- | src/runtime/sys_linux_amd64.s | 19 |
1 files changed, 0 insertions, 19 deletions
diff --git a/src/runtime/sys_linux_amd64.s b/src/runtime/sys_linux_amd64.s index fe9c6bce85..b60057ce83 100644 --- a/src/runtime/sys_linux_amd64.s +++ b/src/runtime/sys_linux_amd64.s @@ -33,10 +33,8 @@ #define SYS_clone 56 #define SYS_exit 60 #define SYS_kill 62 -#define SYS_uname 63 #define SYS_fcntl 72 #define SYS_sigaltstack 131 -#define SYS_mlock 149 #define SYS_arch_prctl 158 #define SYS_gettid 186 #define SYS_futex 202 @@ -789,20 +787,3 @@ TEXT runtime·sbrk0(SB),NOSPLIT,$0-8 SYSCALL MOVQ AX, ret+0(FP) RET - -// func uname(utsname *new_utsname) int -TEXT ·uname(SB),NOSPLIT,$0-16 - MOVQ utsname+0(FP), DI - MOVL $SYS_uname, AX - SYSCALL - MOVQ AX, ret+8(FP) - RET - -// func mlock(addr, len uintptr) int -TEXT ·mlock(SB),NOSPLIT,$0-24 - MOVQ addr+0(FP), DI - MOVQ len+8(FP), SI - MOVL $SYS_mlock, AX - SYSCALL - MOVQ AX, ret+16(FP) - RET |