[PATCH] D84414: [RISCV] Support Shadow Call Stack

[Z. Zheng via Phabricator via llvm-commits]

zzheng marked 2 inline comments as done.
zzheng added inline comments.


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Comment at: llvm/lib/Target/RISCV/RISCVFrameLowering.cpp:60
+  // sw   ra, 0(s2)
+  // addi s2, s2, 4
+  BuildMI(MBB, MI, DL, TII->get(IsRV64 ? RISCV::SD : RISCV::SW))
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jrtc27 wrote:
> Is it intended that the shadow call stack grows *up* unlike the normal stack?
No. Which direction the SCS grows on is trivial.

The memory area hosting SCS is independent of the regular stack; and it's provided by the runtime.
mmap/malloc returns the low address of newly mapped/allocated area. Making the SCS growing down requires the runtime to return upper bound of the SCS. On AArch64, the SCS grows up as well.


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  https://reviews.llvm.org/D84414/new/

https://reviews.llvm.org/D84414