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| author | Michael Pratt <mpratt@google.com> | 2022-10-18 12:01:18 -0400 |
|---|---|---|
| committer | Michael Pratt <mpratt@google.com> | 2022-10-18 20:57:24 +0000 |
| commit | e252dcf9d38ce9192bccacb7e33867cbfbd22b6c (patch) | |
| tree | a1b53f0729de1a567f3597d85b1170a1ee790d5d /src/runtime/sys_linux_arm64.s | |
| parent | a8e4b8c2a793de420ebbe7120c132f0b090d068c (diff) | |
| download | go-e252dcf9d38ce9192bccacb7e33867cbfbd22b6c.tar.xz | |
runtime: always keep global reference to mp until mexit completes
Ms are allocated via standard heap allocation (`new(m)`), which means we
must keep them alive (i.e., reachable by the GC) until we are completely
done using them.
Ms are primarily reachable through runtime.allm. However, runtime.mexit
drops the M from allm fairly early, long before it is done using the M
structure. If that was the last reference to the M, it is now at risk of
being freed by the GC and used for some other allocation, leading to
memory corruption.
Ms with a Go-allocated stack coincidentally already keep a reference to
the M in sched.freem, so that the stack can be freed lazily. This
reference has the side effect of keeping this Ms reachable. However, Ms
with an OS stack skip this and are at risk of corruption.
Fix this lifetime by extending sched.freem use to all Ms, with the value
of mp.freeWait determining whether the stack needs to be freed or not.
Fixes #56243.
Change-Id: Ic0c01684775f5646970df507111c9abaac0ba52e
Reviewed-on: https://go-review.googlesource.com/c/go/+/443716
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Michael Pratt <mpratt@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Diffstat (limited to 'src/runtime/sys_linux_arm64.s')
| -rw-r--r-- | src/runtime/sys_linux_arm64.s | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/src/runtime/sys_linux_arm64.s b/src/runtime/sys_linux_arm64.s index 04a2cd2da1..38ff6ac330 100644 --- a/src/runtime/sys_linux_arm64.s +++ b/src/runtime/sys_linux_arm64.s @@ -56,7 +56,7 @@ TEXT runtime·exit(SB),NOSPLIT|NOFRAME,$0-4 SVC RET -// func exitThread(wait *uint32) +// func exitThread(wait *atomic.Uint32) TEXT runtime·exitThread(SB),NOSPLIT|NOFRAME,$0-8 MOVD wait+0(FP), R0 // We're done using the stack. |