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Clear link register in __bionic_clone.

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Since __bionic_clone uses tail-call to invoke __bionic_clone_entry,
at runtime the unwinder will reach the stack of the clone() function,
which belongs to the parent thread, if the link register is not cleared.

BUG: 14270816
Change-Id: Ia3711c87f8b619debe73748c28b9fb8691ea698e
This commit is contained in:
Ben Cheng
2014-05-23 16:35:21 -07:00
parent a486632e78
commit 8df0fe0c74
2 changed files with 4 additions and 9 deletions
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4
libc/arch-arm64/bionic/__bionic_clone.S
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@@ -61,9 +61,9 @@ ENTRY(__bionic_clone)
.L_bc_child:
# We're in the child now. Set the end of the frame record chain...
.cfi_undefined x29
.cfi_undefined x30
mov x29, xzr
# Setting x30 to 0 will make the unwinder stop at __bionic_clone_entry
mov x30, xzr
# ...and call __bionic_clone_entry with the 'fn' and 'arg' we stored on the child stack.
ldp x0, x1, [sp, #-16]
b __bionic_clone_entry