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authorMartin Stransky <stransky@redhat.com>2018-05-03 13:44:08 +0200
committerMartin Stransky <stransky@redhat.com>2018-05-03 13:44:08 +0200
commite91c961fbfe386901687154034f3f4600dc9749c (patch)
treec5ef618c0a29264b9a02fb7ef43ef1bc2f79e4ed /bug1375074-save-restore-x28.patch
parentMerge branch 'master' into f27 (diff)
parentAdded patch from mozbz#1375074 - fixes aarch64 baseline JIT crashes (diff)
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Merge branch 'master' into f27
Diffstat (limited to 'bug1375074-save-restore-x28.patch')
-rw-r--r--bug1375074-save-restore-x28.patch74
1 files changed, 74 insertions, 0 deletions
diff --git a/bug1375074-save-restore-x28.patch b/bug1375074-save-restore-x28.patch
new file mode 100644
index 0000000..57a83a2
--- /dev/null
+++ b/bug1375074-save-restore-x28.patch
@@ -0,0 +1,74 @@
+# HG changeset patch
+# User Lars T Hansen <lhansen@mozilla.com>
+# Date 1519822672 -3600
+# Wed Feb 28 13:57:52 2018 +0100
+# Node ID 672f0415217b202ae59a930769dffd9d6ba6b87c
+# Parent 825fd04dacc6297d3a980ec4184079405950b35d
+Bug 1375074 - Save and restore non-volatile x28 on ARM64 for generated unboxed object constructor.
+
+diff --git a/js/src/jit-test/tests/bug1375074.js b/js/src/jit-test/tests/bug1375074.js
+new file mode 100644
+--- /dev/null
++++ b/js/src/jit-test/tests/bug1375074.js
+@@ -0,0 +1,18 @@
++// This forces the VM to start creating unboxed objects and thus stresses a
++// particular path into generated code for a specialized unboxed object
++// constructor.
++
++var K = 2000; // 2000 should be plenty
++var s = "[";
++var i;
++for ( i=0; i < K-1; i++ )
++ s = s + `{"i":${i}},`;
++s += `{"i":${i}}]`;
++var v = JSON.parse(s);
++
++assertEq(v.length == K, true);
++
++for ( i=0; i < K; i++) {
++ assertEq(v[i] instanceof Object, true);
++ assertEq(v[i].i, i);
++}
+diff --git a/js/src/vm/UnboxedObject.cpp b/js/src/vm/UnboxedObject.cpp
+--- a/js/src/vm/UnboxedObject.cpp
++++ b/js/src/vm/UnboxedObject.cpp
+@@ -95,7 +95,15 @@ UnboxedLayout::makeConstructorCode(JSCon
+ #endif
+
+ #ifdef JS_CODEGEN_ARM64
+- // ARM64 communicates stack address via sp, but uses a pseudo-sp for addressing.
++ // ARM64 communicates stack address via sp, but uses a pseudo-sp (PSP) for
++ // addressing. The register we use for PSP may however also be used by
++ // calling code, and it is nonvolatile, so save it. Do this as a special
++ // case first because the generic save/restore code needs the PSP to be
++ // initialized already.
++ MOZ_ASSERT(PseudoStackPointer64.Is(masm.GetStackPointer64()));
++ masm.Str(PseudoStackPointer64, vixl::MemOperand(sp, -16, vixl::PreIndex));
++
++ // Initialize the PSP from the SP.
+ masm.initStackPtr();
+ #endif
+
+@@ -233,7 +241,22 @@ UnboxedLayout::makeConstructorCode(JSCon
+ masm.pop(ScratchDoubleReg);
+ masm.PopRegsInMask(savedNonVolatileRegisters);
+
++#ifdef JS_CODEGEN_ARM64
++ // Now restore the value that was in the PSP register on entry, and return.
++
++ // Obtain the correct SP from the PSP.
++ masm.Mov(sp, PseudoStackPointer64);
++
++ // Restore the saved value of the PSP register, this value is whatever the
++ // caller had saved in it, not any actual SP value, and it must not be
++ // overwritten subsequently.
++ masm.Ldr(PseudoStackPointer64, vixl::MemOperand(sp, 16, vixl::PostIndex));
++
++ // Perform a plain Ret(), as abiret() will move SP <- PSP and that is wrong.
++ masm.Ret(vixl::lr);
++#else
+ masm.abiret();
++#endif
+
+ masm.bind(&failureStoreOther);
+
bgstack15