Set minimum stack size using PT_GNU_STACK header for Musl

[jkotas]

See http://git.musl-libc.org/cgit/musl/commit/?id=7b3348a98c139b4b4238384e52d4b0eb237e4833

This can be done once the minimum target musl version is 1.21. We are on 1.20 right now (it is what CI uses at least).

Cleanup with this issue number once implemented.

[kant2002]

I have a question. Right now docker images for .NET Runtime seems to be shipping with version of Alpine at least 3.13
I take that from https://hub.docker.com/_/microsoft-dotnet-nightly-runtime/
According to Alpine website version 3.13 has Musl at least 1.2 which definitely bigger then 1.1.20, and even 3.10 (released 2019-06-13) has 1.1.22
Infra still uses 3.9 at least Linux-musl run on mcr.microsoft.com/dotnet-buildtools/prereqs:alpine-3.9-WithNode-20200602002639-0fc54a3
2 years is probably too much to drop support for 3.9, but given that all containers on 3.13 I have mixed signals. It appears that only infra holding back, isn't it?

Second question. I notice following lines in pal/src/CMakeList.txt
https://github.com/dotnet/runtimelab/blob/5c2866363ebbd5364a4778d981cb61eaada039e3/src/coreclr/pal/src/CMakeLists.txt#L86-L92
In addition to ENSURE_PRIMARY_STACK_SIZE I see DONT_SET_RLIMIT_NOFILE, which does not present in nativeaot component. Should in't be in lines below
https://github.com/dotnet/runtimelab/blob/5c2866363ebbd5364a4778d981cb61eaada039e3/src/coreclr/nativeaot/CMakeLists.txt#L39-L43

[jkotas]

It appears that only infra holding back, isn't it?

Yes, I have opened issue in dotnet/runtime to bump the alpine version used for builds.

DONT_SET_RLIMIT_NOFILE

NativeAOT debugging is nothing like CoreCLR debugging. It is unlikely that whatever the issue is with CoreCLR debugging applies to NativeAOT too.

[ayakael]

I'm encountering what seems to be an issue with the stack size on linux-musl-s390x with roslyn where I get a bunch of System.InsufficientExecutionStackException: Insufficient stack to continue executing the program safely errors. I added -Wl,-z,stack-size=8198144 at a few locations, via <_MonoCXXFLAGS Include="-Wl,-z,stack-size=8198144" /> on mono.proj and:

diff --git a/src/dotnet-v6.0.109/src/runtime/eng/common/cross/toolchain.cmake.orig b/src/dotnet-v6.0.109/src/runtime/eng/common/cross/toolchain.cmake
index b0430c1a36..12522702ed 100644
--- a/src/dotnet-v6.0.109/src/runtime/eng/common/cross/toolchain.cmake.orig
+++ b/src/dotnet-v6.0.109/src/runtime/eng/common/cross/toolchain.cmake
@@ -149,6 +149,7 @@ endfunction()
 if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
   add_toolchain_linker_flag("-Wl,--rpath-link=${CROSS_ROOTFS}/lib/${TOOLCHAIN}")
   add_toolchain_linker_flag("-Wl,--rpath-link=${CROSS_ROOTFS}/usr/lib/${TOOLCHAIN}")
+  add_toolchain_linker_flag("-Wl,-z,stack-size=8198144")
 endif()
 
 if(TARGET_ARCH_NAME STREQUAL "armel")

Build doesn't seem to pick-up this setting, as I'm still getting the errors. The bug isn't reproducible on linux-musl-{x64,arm,arm64}, thus it's likely to do with mono.

Any advice on how I might set the minimum stack size on mono?

Issue thread on roslyn: dotnet/roslyn#64423

[ayakael]

Of note, I'm implementing a fix for the stack issues in #76500 by porting ensure_stack_size to mono modeled after coreclr.

[jkotas]

Did you figure out what was wrong with -z,stack-size The linker option would be the preferred way to fix this given that we should be on new-enough Alpine version now.

[ayakael]

Did you figure out what was wrong with -z,stack-size The linker option would be the preferred way to fix this given that we should be on new-enough Alpine version now.

Unfortunately not. Despite my best attempts I still encountered stack exceptions. The error referenced above was actually caused by changes in dotnet/roslyn#57003 not being picked up properly by the Alpine package builder.

The real stack issue with mono is tracked in #76805 and the linker option, from memory, didn't have any effect on behavior. I lack the time to circle back and find a proper fix, but I've setup an aport that reproduces the bug on linux-musl-x64 by building runtime with /p:PrimaryRuntimeFlavor=Mono. It is available here and you can run it via the following steps:

git clone https://gitlab.alpinelinux.org/ayakael/aports -b dotnet7/mono-fsharp
cd  aports/testing/dotnet7-stage0
abuild deps unpack prepare build

It should fail with error code 134.

[ayakael]

I circled back and tried the following for dotnet 7.0.100:

diff --git a/src/runtime/src/mono/mono.proj b/src/runtime/src/mono/mono.proj
index 38731e96866..753c0d7ffa9 100644
--- a/src/runtime/src/mono/mono.proj
+++ b/src/runtime/src/mono/mono.proj
@@ -464,11 +464,25 @@
     <!-- Linux options -->
     <ItemGroup Condition="'$(TargetsLinux)' == true">
       <_MonoCFLAGS Include="-Wl,--build-id=sha1" />
+      <_MonoCFLAGS Include="-Wno-int-conversion" />
       <_MonoCXXFLAGS Include="-Wl,--build-id=sha1" />
+      <_MonoCXXFLAGS Include="-Wno-int-conversion" />
     </ItemGroup>
     <ItemGroup Condition="'$(RealTargetOS)' == 'Linux'">
       <_MonoAOTCFLAGS Include="-Wl,--build-id=sha1" />
+      <_MonoAOTCFLAGS Include="-Wno-int-conversion" />
       <_MonoAOTCXXFLAGS Include="-Wl,--build-id=sha1" />
+      <_MonoAOTCXXFLAGS Include="-Wno-int-conversion" />
+    </ItemGroup>
+    <ItemGroup Condition="'$(TargetsLinuxMusl)' == 'true'">
+      <_MonoAOTCFLAGS Include="-Wl,-z,stack-size=8198144" />
+      <_MonoAOTCXXFLAGS Include="-Wl,-z,stack-size=8198144" />
+      <_MonoCFLAGS Include="-Wl,-z,stack-size=8198144" />
+      <_MonoCXXFLAGS Include="-Wl,-z,stack-size=8198144" />
+      <_MonoAOTCFLAGS Include="-lucontext" />
+      <_MonoAOTCXXFLAGS Include="-lucontext" />
+      <_MonoCFLAGS Include="-lucontext" />
+      <_MonoCXXFLAGS Include="-lucontext" />
     </ItemGroup>
 
     <!-- Devloop features -->

Build failure due to #76805 continues. For now, only the implementation of ENSURE_STACK_SIZE in #76500 for mono helps with this issue.