> On May 16, 2024, at 3:07 PM, Nelson Chu wrote: > > On Thu, May 16, 2024 at 2:16 PM Hau Hsu > wrote: >> Hi Nelson, >> >> Sorry for the late reply. >> >>> On May 8, 2024, at 9:00 AM, Nelson Chu > wrote: >>> >>> Can you provide the testcase to show the case which I mentioned in the pr13302? Which is that an ifunc with a dynamic jump slot calls another ifunc, and are not in the rel.dyn. >> I am not quite sure what's the issue you mentioned in PR13302. >> You mean the order issue of cause by one ifunc (generates JUMP_SLOT[32|64]) calls another JUMP_SLOT[32|64] ifunc? >> >>> Since according to the testcase below, it seems no requirement to apply this fix though. >> The new test case uses two methods to call ifuncs: >> 1. Through a normal function call: PLT + GOT >> 2. Through a global function pointer: GOT only >> >> Without the fix, the relocation of the first method overwrites the second's. >> The relocation section of my test case would be: >> >> Relocation section '.rela.plt' at offset 0x94 contains 2 entries: >> Offset Info Type Sym. Value Symbol's Name + Addend >> 000110dc 0000003a R_RISCV_IRELATIVE 100c0 >> 00000000 00000000 R_RISCV_NONE 0 >> >> >> With the fix, it becomes >> >> Relocation section '.rela.plt' at offset 0x94 contains 2 entries: >> Offset Info Type Sym. Value Symbol's Name + Addend >> 000110e0 0000003a R_RISCV_IRELATIVE 100c0 >> 000110dc 0000003a R_RISCV_IRELATIVE 100c0 >> > > So it seems like the overwrite problem, not the order problem we were discussing in the pr13302... Yes. Sorry that I didn't explain the whole story well. This PR is originally to fix the overwrite problem, as my commit message says: > This commit resolved two issues: > 1. When an ifunc is referenced by a pointer, the relocation of > the pointer in .rela.plt would be overwritten by normal ifunc call. We found the issue when building glibc testbench statically. To fix this issue, I sent a PR (https://sourceware.org/pipermail/binutils/2023-July/128485.html) about a year ago. The PR use the method smilier to your previous commit, i.e. https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=51a8a7c2e3cc0730831963651a55d23d1fae624d Then you suggested to check whether the relocation order is correct. After that I checked the X86 implementation, I sent this PR. > >>>> --- /dev/null >>>> +++ b/ld/testsuite/ld-riscv-elf/ifunc-macro.s >>>> @@ -0,0 +1,19 @@ >>>> +/* Define macros to handle similar behaviors for rv32/rv64. >>>> + Assumes macro "__64_bit__" defined for rv64. >>>> + The macro is specifically defined for ifunc tests in ld-riscv-elf.exp. */ >>>> + >>>> +.macro PTR_DATA name >>>> +.ifdef __64_bit__ >>>> + .quad \name >>>> +.else >>>> + .long \name >>>> +.endif >>>> +.endm >>>> + >>>> +.macro LOAD rd, rs, offset >>>> +.ifdef __64_bit__ >>>> + ld \rd, \offset (\rs) >>>> +.else >>>> + lw \rd, \offset (\rs) >>>> +.endif >>>> +.endm > > Btw, can we not use these macroes? No problem. I just want to avoid similar codes in the ifunc tests. > > Nelson