i#3544 RV64: Implement return address handling for post wrappers

[apach301]

Substitute value of return address register to enable post wrappers.

Partially enables drwrap-test for RISC-V:

1. Add drwrap-test-callconv test to pipeline
2. Partially supported drwrap-drreg-test: check for pre/post wrappers passes,
   but checks for clean_call and restore registers functionality are failing.

Issue: #3544

[ksco]

I suppose this is covered by some tests, do these tests work now? If yes, maybe state that in the PR description and enable it in the RUN_ON_QEMU label for RISC-V so it can be checked by the CI.

[apach301]

I suppose this is covered by some tests, do these tests work now? If yes, maybe state that in the PR description and enable it in the RUN_ON_QEMU label for RISC-V so it can be checked by the CI.

I tested it only on my DR client. I don't familiar with DynamoRIO test system, and all I found is

dynamorio/suite/tests/CMakeLists.txt

Line 3032 in 8e23247

if (NOT RISCV64)

and

dynamorio/suite/tests/CMakeLists.txt

Line 3061 in 8e23247

if (NOT RISCV64) # TODO i#3544: Port tests to RISC-V 64

that are disabling drwrap tests on RISC-V. Is it sufficient to just remove the guards to enable these tests?

Also, as much as I understand, the one failing test (ci-aarchxx) isn't related to these changes, and is failing on current master.

[ksco]

Yes, remove the guards should be enough for CMake to build the test, then add the test name into suite/tests/CMakeLists.txt#L6152 and run ctest -L RUNS_ON_QEMU see if the test passes.

[apach301]

Yes, remove the guards should be enough for CMake to build the test, then add the test name into suite/tests/CMakeLists.txt#L6152 and run ctest -L RUNS_ON_QEMU see if the test passes.

The tests couldn't be compiled currently for RISCV64: it needs a platform-depend fixes in suite/tests/client-interface/drwrap-drreg-test.dll.c, which requires implementing some functions in core/ir/riscv64/instr_create_api.h.in.

[ksco]

I suppose you’re referring to XINST_CREATE_cmp() and XINST_CREATE_jmp_cond? There won’t be such thing on RISC-V since we don’t have eflags. You can use INSTR_CREATE_beq() to rewrite this part for RISC-V.

[apach301]

I suppose you’re referring to XINST_CREATE_cmp() and XINST_CREATE_jmp_cond? There won’t be such thing on RISC-V since we don’t have eflags. You can use INSTR_CREATE_beq() to rewrite this part for RISC-V.

Finally being able to compile and run tests. Test drwrap-callconv seems to work, but with drwrap-drreg things more complicated. The part with pre/post wrappers passes, the part with drreg save/restore registers fails.

Moreover, for riscv default callconv is not working, it requires explicitly setup DRWRAP_CALLCONV_RISCV_LP64 | DRWRAP_REPLACE_RETADDR flags

[ksco]

Please don't do force push, see: https://dynamorio.org/page_code_reviews.html.

[apach301]

@derekbruening @ksco Disabled unimplemented drwrap-drreg-test, now CI for riscv passes.

[derekbruening]

Please see https://dynamorio.org/page_code_reviews.html#autotoc_md118 "request a re-review...clicking the re-review button..."

[ksco]

Sorry still on vacation this week.