[llvm-dev] [PPC] Linker fails on -fstack-protector

Tim Shen via llvm-dev
Mon, 25 Jan 2016 19:57:43 -0000

When -fstack-protector is turned on, linker fails to find the symbol
"__stack_chk_guard"
because at least for powerpc64le, glibc doesn't provide this symbol.
Instead, they put the stack guard into TCB.

x86 fixed this issue by injecting a special address space (which is later
translated to TCB register access) and hard code the offset of stack_guard,
but I don't see a easy way to handle address spaces in ppc.

A cleaner solution could be adding an IR intrinsic llvm.get_tcb_address()
and hard code the offset of stack_guard member, since they aren't supposed
to change.

Details are in the bug: https://llvm.org/bugs/show_bug.cgi?id=26226

Any ideas?

Thanks!
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