llvmorg-github-actions[bot] wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-libunwind Author: quic-k <details> <summary>Changes</summary> The Hexagon save and restore routines dropped GPRs, producing an incomplete context. UnwindRegistersSave.S (__unw_getcontext): save r0-r7 (stores began at __r[8]), drop a dead "r1 = memw(r30)" before the PC store, and return UNW_ESUCCESS instead of a stale non-zero value. UnwindRegistersRestore.S (jumpto): restore the missing r2-r7 (r0/r1 and r8-r31 were already handled), and fix the stale "pointer is in r2" comment (it is r0). --- Full diff: https://github.com/llvm/llvm-project/pull/208753.diff 2 Files Affected: - (modified) libunwind/src/UnwindRegistersRestore.S (+12-1) - (modified) libunwind/src/UnwindRegistersSave.S (+21-3) ``````````diff diff --git a/libunwind/src/UnwindRegistersRestore.S b/libunwind/src/UnwindRegistersRestore.S index 8f84f4d456a35..37e8156408cf2 100644 --- a/libunwind/src/UnwindRegistersRestore.S +++ b/libunwind/src/UnwindRegistersRestore.S @@ -947,11 +947,22 @@ DEFINE_LIBUNWIND_FUNCTION(_ZN9libunwind14Registers_or1k6jumptoEv) #elif defined(__hexagon__) # On entry: -# thread_state pointer is in r2 +# thread_state pointer is in r0 DEFINE_LIBUNWIND_FUNCTION(_ZN9libunwind17Registers_hexagon6jumptoEv) # # void libunwind::Registers_hexagon::jumpto() # +# The context layout is hexagon_thread_state_t: unsigned int __r[35] +# __r[0..31] = r0..r31, __r[32] = predicates, __r[33] = PC. +# Offsets: __r[n] is at byte offset n*4. r0 is the context pointer, so +# it is restored last; r31 is loaded with the saved PC as the jumpr target. + r2 = memw(r0+#8) + r3 = memw(r0+#12) + r4 = memw(r0+#16) + r5 = memw(r0+#20) + r6 = memw(r0+#24) + r7 = memw(r0+#28) + r8 = memw(r0+#32) r9 = memw(r0+#36) r10 = memw(r0+#40) diff --git a/libunwind/src/UnwindRegistersSave.S b/libunwind/src/UnwindRegistersSave.S index a82ebd1ead23b..f44f6a1331968 100644 --- a/libunwind/src/UnwindRegistersSave.S +++ b/libunwind/src/UnwindRegistersSave.S @@ -1103,8 +1103,21 @@ DEFINE_LIBUNWIND_FUNCTION(__unw_getcontext) # On entry: # thread_state pointer is in r0 # +# The context layout is hexagon_thread_state_t: unsigned int __r[35] +# __r[0..31] = r0..r31, __r[32] = predicates, __r[33] = PC, __r[34] = unused +# Offsets: __r[n] is at byte offset n*4. +# #define OFFSET(offset) (offset/4) DEFINE_LIBUNWIND_FUNCTION(__unw_getcontext) + // Save r1-r7 first (r0 is the context pointer, saved last) + memw(r0+#4) = r1 + memw(r0+#8) = r2 + memw(r0+#12) = r3 + memw(r0+#16) = r4 + memw(r0+#20) = r5 + memw(r0+#24) = r6 + memw(r0+#28) = r7 + memw(r0+#32) = r8 memw(r0+#36) = r9 memw(r0+#40) = r10 @@ -1134,12 +1147,17 @@ DEFINE_LIBUNWIND_FUNCTION(__unw_getcontext) memw(r0+#116) = r29 memw(r0+#120) = r30 memw(r0+#124) = r31 - r1 = c4 // Predicate register + + r1 = c4 // Predicate register memw(r0+#128) = r1 - r1 = memw(r30) // *FP == Saved FP - r1 = r31 + + r1 = r31 // Store return address as PC memw(r0+#132) = r1 + // Save r0 (the context pointer itself) last + memw(r0+#0) = r0 + + r0 = #0 // return UNW_ESUCCESS jumpr r31 #elif defined(__sparc__) && defined(__arch64__) `````````` </details> https://github.com/llvm/llvm-project/pull/208753 _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
