Re: [OE-core] [PATCH] webkitgtk: Reduce stack and heap sizes for jsc on musl

["Khem Raj" <raj.khem@gmail.com>]

On Wed, Mar 17, 2021 at 4:10 AM Alexander Kanavin
<alex.kanavin@gmail.com> wrote:
>
> Please Khem, send these patches upstream first.
>

its widely discussed problem in webkit and musl circuits, the patch
here is carried by almost all musl distros in some form.
see https://bugs.webkit.org/show_bug.cgi?id=187485
unfortunately, there is no final solution yet which is acceptable
upstream as such.

> Alex
>
> On Wed, 17 Mar 2021 at 01:32, Khem Raj <raj.khem@gmail.com> wrote:
>>
>> Fixes
>>
>> [YOCTO #14281]
>>
>> Signed-off-by: Khem Raj <raj.khem@gmail.com>
>> Cc: Andrei Gherzan <andrei@gherzan.com>
>> ---
>>  .../webkitgtk/musl-lower-stack-usage.patch    | 51 +++++++++++++++++++
>>  meta/recipes-sato/webkit/webkitgtk_2.30.5.bb  |  1 +
>>  2 files changed, 52 insertions(+)
>>  create mode 100644 meta/recipes-sato/webkit/webkitgtk/musl-lower-stack-usage.patch
>>
>> diff --git a/meta/recipes-sato/webkit/webkitgtk/musl-lower-stack-usage.patch b/meta/recipes-sato/webkit/webkitgtk/musl-lower-stack-usage.patch
>> new file mode 100644
>> index 0000000000..3d66766d9a
>> --- /dev/null
>> +++ b/meta/recipes-sato/webkit/webkitgtk/musl-lower-stack-usage.patch
>> @@ -0,0 +1,51 @@
>> +reduce thread stack and heap usage for javascriptcore on musl
>> +
>> +default sizes for musl are smaller compared to glibc, this matches
>> +to musl defaults, avoid stack overflow crashes in jscore
>> +
>> +Upstream-Status: Pending
>> +Signed-off-by: Khem Raj <raj.khem@gmail.com>
>> +
>> +--- a/Source/JavaScriptCore/runtime/OptionsList.h
>> ++++ b/Source/JavaScriptCore/runtime/OptionsList.h
>> +@@ -75,6 +75,18 @@ constexpr bool enableWebAssemblyStreamin
>> + // On instantiation of the first VM instance, the Options will be write protected
>> + // and cannot be modified thereafter.
>> +
>> ++#if OS(LINUX) && !defined(__GLIBC__)
>> ++// non-glibc options on linux ( musl )
>> ++constexpr unsigned jscMaxPerThreadStack = 80 * KB;
>> ++constexpr unsigned jscSoftReservedZoneSize = 32 * KB;
>> ++constexpr unsigned jscReservedZoneSize = 16 * KB;
>> ++#else
>> ++//default
>> ++constexpr unsigned jscMaxPerThreadStack = 4 * MB;
>> ++constexpr unsigned jscSoftReservedZoneSize = 128 * KB;
>> ++constexpr unsigned jscReservedZoneSize = 64 * KB;
>> ++#endif
>> ++
>> + #define FOR_EACH_JSC_OPTION(v)                                          \
>> +     v(Bool, useKernTCSM, defaultTCSMValue(), Normal, "Note: this needs to go before other options since they depend on this value.") \
>> +     v(Bool, validateOptions, false, Normal, "crashes if mis-typed JSC options were passed to the VM") \
>> +@@ -90,9 +102,9 @@ constexpr bool enableWebAssemblyStreamin
>> +     \
>> +     v(Bool, reportMustSucceedExecutableAllocations, false, Normal, nullptr) \
>> +     \
>> +-    v(Unsigned, maxPerThreadStackUsage, 5 * MB, Normal, "Max allowed stack usage by the VM") \
>> +-    v(Unsigned, softReservedZoneSize, 128 * KB, Normal, "A buffer greater than reservedZoneSize that reserves space for stringifying exceptions.") \
>> +-    v(Unsigned, reservedZoneSize, 64 * KB, Normal, "The amount of stack space we guarantee to our clients (and to interal VM code that does not call out to clients).") \
>> ++    v(Unsigned, maxPerThreadStackUsage, jscMaxPerThreadStack, Normal, "Max allowed stack usage by the VM") \
>> ++    v(Unsigned, softReservedZoneSize, jscSoftReservedZoneSize, Normal, "A buffer greater than reservedZoneSize that reserves space for stringifying exceptions.") \
>> ++    v(Unsigned, reservedZoneSize, jscReservedZoneSize, Normal, "The amount of stack space we guarantee to our clients (and to interal VM code that does not call out to clients).") \
>> +     \
>> +     v(Bool, crashOnDisallowedVMEntry, ASSERT_ENABLED, Normal, "Forces a crash if we attempt to enter the VM when disallowed") \
>> +     v(Bool, crashIfCantAllocateJITMemory, false, Normal, nullptr) \
>> +@@ -601,7 +613,7 @@ public:
>> +     bool init(const char*);
>> +     bool isInRange(unsigned);
>> +     const char* rangeString() const { return (m_state > InitError) ? m_rangeString : s_nullRangeStr; }
>> +-
>> ++
>> +     void dump(PrintStream& out) const;
>> +
>> + private:
>> diff --git a/meta/recipes-sato/webkit/webkitgtk_2.30.5.bb b/meta/recipes-sato/webkit/webkitgtk_2.30.5.bb
>> index d0a41f48c7..36d33f550d 100644
>> --- a/meta/recipes-sato/webkit/webkitgtk_2.30.5.bb
>> +++ b/meta/recipes-sato/webkit/webkitgtk_2.30.5.bb
>> @@ -20,6 +20,7 @@ SRC_URI = "https://www.webkitgtk.org/releases/${BPN}-${PV}.tar.xz \
>>             file://include_xutil.patch \
>>             file://reduce-memory-overheads.patch \
>>             file://0001-Extend-atomics-check-to-include-1-byte-CAS-test.patch \
>> +           file://musl-lower-stack-usage.patch \
>>             "
>>
>>  SRC_URI[sha256sum] = "7d0dab08e3c5ae07bec80b2822ef42e952765d5724cac86eb23999bfed5a7f1f"
>> --
>> 2.31.0
>>
>>
>> 
>>