[libcxx-commits] [PATCH] D158655: [libunwind][AIX] Fix problem with stepping up from a leaf function when unwinding started in a signal handler

[Hubert Tong via Phabricator via libcxx-commits]

hubert.reinterpretcast added inline comments.


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Comment at: libunwind/src/UnwindCursor.hpp:2504
+    // sigcontext is used as the return address.
+    if (!usedLRFromSigContext)
+      newRegisters.setSP(lastStack);
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I don't think there should a condition here at all. A fix needs to be made at line 2324 (otherwise the wrong link area would be used for retrieving a saved LR when `stores_bc` is `0` and `saves_lr` is `1`).


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Comment at: libunwind/src/UnwindCursor.hpp:2324
   // lastStack points to the stack frame of the next routine up.
   pint_t lastStack = *(reinterpret_cast<pint_t *>(registers.getSP()));
 
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hubert.reinterpretcast wrote:
> This only covers the case when `stores_bc` is `1` in the traceback table.
@xingxue, is a change coming for this? I think this also falls into "cases that arise when unwinding past a signal handler".


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D158655/new/

https://reviews.llvm.org/D158655