[libunwind] [sparc] Add SPARCv9 support
Adds libunwind support for SPARCv9 (aka sparc64). This is a rebase of @kettenis' patch D32450, which I created (with his permission) because the original review has become inactive.
The changes are of a cosmetic nature to make it fit better with the new code style, and to reuse the existing SPARCv8 code, whenever possible.
Please let me know if I posted this on the wrong place. Also, the summary of the original review is reproduced below:
> This adds unwinder support for 64-bit SPARC (aka SPARCv9). The implementation was done on OpenBSD/sparc64, so it takes StackGhost into account:
>
> https://www.usenix.org/legacy/publications/library/proceedings/sec01/full_papers/frantzen/frantzen_html/index.html
>
> Since StackGhost xor's return addresses with a random cookie before storing them on the stack, the unwinder has to do some extra work to recover those. This is done by introducing a new kRegisterInCFADecrypt "location" type that is used to implement the DW_CFA_GNU_window_save opcode. That implementation is SPARC-specific, but should work for 32-bit SPARC as well. DW_CFA_GNU_window_save is only ever generated on SPARC as far as I know.
Co-authored-by: Mark Kettenis
Reviewed By: #libunwind, thesamesam, MaskRay, Arfrever
Differential Revision: https://reviews.llvm.org/D116857
NOKEYCHECK=True
GitOrigin-RevId: 2b9554b8850192bdd86c02eb671de1d866df8d87
diff --git a/src/DwarfParser.hpp b/src/DwarfParser.hpp
index 8630178..b5a5316 100644
--- a/src/DwarfParser.hpp
+++ b/src/DwarfParser.hpp
@@ -71,6 +71,7 @@
kRegisterUnused,
kRegisterUndefined,
kRegisterInCFA,
+ kRegisterInCFADecrypt, // sparc64 specific
kRegisterOffsetFromCFA,
kRegisterInRegister,
kRegisterAtExpression,
@@ -733,7 +734,8 @@
"DW_CFA_GNU_negative_offset_extended(%" PRId64 ")\n", offset);
break;
-#if defined(_LIBUNWIND_TARGET_AARCH64) || defined(_LIBUNWIND_TARGET_SPARC)
+#if defined(_LIBUNWIND_TARGET_AARCH64) || defined(_LIBUNWIND_TARGET_SPARC) || \
+ defined(_LIBUNWIND_TARGET_SPARC64)
// The same constant is used to represent different instructions on
// AArch64 (negate_ra_state) and SPARC (window_save).
static_assert(DW_CFA_AARCH64_negate_ra_state == DW_CFA_GNU_window_save,
@@ -767,8 +769,31 @@
}
break;
#endif
+
+#if defined(_LIBUNWIND_TARGET_SPARC64)
+ // case DW_CFA_GNU_window_save:
+ case REGISTERS_SPARC64:
+ // Don't save %o0-%o7 on sparc64.
+ // https://reviews.llvm.org/D32450#736405
+
+ for (reg = UNW_SPARC_L0; reg <= UNW_SPARC_I7; reg++) {
+ if (reg == UNW_SPARC_I7)
+ results->setRegister(
+ reg, kRegisterInCFADecrypt,
+ static_cast<int64_t>((reg - UNW_SPARC_L0) * sizeof(pint_t)),
+ initialState);
+ else
+ results->setRegister(
+ reg, kRegisterInCFA,
+ static_cast<int64_t>((reg - UNW_SPARC_L0) * sizeof(pint_t)),
+ initialState);
+ }
+ _LIBUNWIND_TRACE_DWARF("DW_CFA_GNU_window_save\n");
+ break;
+#endif
}
break;
+
#else
(void)arch;
#endif