From: Jens Remus Date: Fri, 16 Jan 2026 00:44:12 +0000 (-0800) Subject: s390: gas: sframe: do not reject .cfi_register REG_SP, REG X-Git-Tag: binutils-2_46~246 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c4b575f3b54a0a88778f3da034a5790892c8ed8e;p=thirdparty%2Fbinutils-gdb.git s390: gas: sframe: do not reject .cfi_register REG_SP, REG On s390 64-bit (s390x) compilers may save the SP, FP, and RA registers, which are of interest in SFrame, in other registers, such as floating- point registers, for instance when in a leaf function. SFrame does not explicitly track the SP. Instead SFrame relies on the architecture-specific CFA definition to recover the SP. The s390x ELF ABI [1] defines the CFA as SP at call site + 160, which results in the implicit SP recovery rule SP = CFA - 160. Assuming that CFI on s390 64-bit (s390x) adheres to the CFA definition, it is safe to ignore any CFI directives, that specify the SP register at entry to be saved either on the stack or in another register, as the SP can then always be recovered using the implicit SP recovery rule. [1]: s390x ELF ABI, https://github.com/IBM/s390x-abi/releases Committed-by: Indu Bhagat gas/ * gen-sframe.c (sframe_xlate_do_register): Ignore .cfi_register SP on s390x. gas/testsuite/ * gas/cfi-sframe/cfi-sframe.exp (cfi-sframe-s390x-err-4): Rename test to cfi-sframe-s390x-sp-register. * gas/cfi-sframe/cfi-sframe-s390x-err-4.d: Rename to ... * gas/cfi-sframe/cfi-sframe-s390x-err-4.s: Likewise. * gas/cfi-sframe/cfi-sframe-s390x-sp-register.d: This. Test that .cfi_register SP is ignored. * gas/cfi-sframe/cfi-sframe-s390x-sp-register.s: Likewise. Add minimal assembler sample. --- diff --git a/gas/gen-sframe.c b/gas/gen-sframe.c index 931c14c4b02..0241d4424b6 100644 --- a/gas/gen-sframe.c +++ b/gas/gen-sframe.c @@ -1536,7 +1536,8 @@ sframe_xlate_do_register (struct sframe_xlate_ctx *xlate_ctx, if (cfi_insn->u.rr.reg1 == SFRAME_CFA_RA_REG /* SFrame does not track SP explicitly. */ - || cfi_insn->u.rr.reg1 == SFRAME_CFA_SP_REG + || (cfi_insn->u.rr.reg1 == SFRAME_CFA_SP_REG + && sframe_get_abi_arch () != SFRAME_ABI_S390X_ENDIAN_BIG) || cfi_insn->u.rr.reg1 == SFRAME_CFA_FP_REG) { as_warn (_("no SFrame FDE emitted; %s register %u in .cfi_register"), diff --git a/gas/testsuite/gas/cfi-sframe/cfi-sframe-s390x-err-4.s b/gas/testsuite/gas/cfi-sframe/cfi-sframe-s390x-err-4.s deleted file mode 100644 index 7c0bedab9f2..00000000000 --- a/gas/testsuite/gas/cfi-sframe/cfi-sframe-s390x-err-4.s +++ /dev/null @@ -1,5 +0,0 @@ - .cfi_sections .sframe - .cfi_startproc - .cfi_register r15, r5 - br %r7 - .cfi_endproc diff --git a/gas/testsuite/gas/cfi-sframe/cfi-sframe-s390x-err-4.d b/gas/testsuite/gas/cfi-sframe/cfi-sframe-s390x-sp-register.d similarity index 53% rename from gas/testsuite/gas/cfi-sframe/cfi-sframe-s390x-err-4.d rename to gas/testsuite/gas/cfi-sframe/cfi-sframe-s390x-sp-register.d index 1703d817ea9..5203f6dc653 100644 --- a/gas/testsuite/gas/cfi-sframe/cfi-sframe-s390x-err-4.d +++ b/gas/testsuite/gas/cfi-sframe/cfi-sframe-s390x-sp-register.d @@ -1,6 +1,5 @@ #name: SFrame generation on s390x - .cfi_register with SP #as: --gsframe -#warning: SP register 15 in \.cfi\_register #objdump: --sframe=.sframe #... Contents of the SFrame section .sframe: @@ -9,7 +8,14 @@ Contents of the SFrame section .sframe: Version: SFRAME_VERSION_3 Flags: SFRAME_F_FDE_FUNC_START_PCREL - Num FDEs: 0 - Num FREs: 0 + Num FDEs: 1 + Num FREs: 3 + Function Index : + + func idx \[0\]: pc = 0x0, size = 16 bytes + STARTPC +CFA +FP +RA + + 0+0000 +sp\+160 +u +u + + 0+000a +sp\+320 +u +u + + 0+000e +sp\+160 +u +u + #pass diff --git a/gas/testsuite/gas/cfi-sframe/cfi-sframe-s390x-sp-register.s b/gas/testsuite/gas/cfi-sframe/cfi-sframe-s390x-sp-register.s new file mode 100644 index 00000000000..223588faca7 --- /dev/null +++ b/gas/testsuite/gas/cfi-sframe/cfi-sframe-s390x-sp-register.s @@ -0,0 +1,11 @@ + .cfi_sections .sframe + .cfi_startproc + ldgr %f1,%r15 + .cfi_register r15, f1 + lay %r15,-160(%r15) + .cfi_adjust_cfa_offset 160 + lgdr %r15,%f1 + .cfi_restore r15 + .cfi_adjust_cfa_offset -160 + br %r14 + .cfi_endproc diff --git a/gas/testsuite/gas/cfi-sframe/cfi-sframe.exp b/gas/testsuite/gas/cfi-sframe/cfi-sframe.exp index 3f246d2da24..2e0942657ae 100644 --- a/gas/testsuite/gas/cfi-sframe/cfi-sframe.exp +++ b/gas/testsuite/gas/cfi-sframe/cfi-sframe.exp @@ -100,11 +100,11 @@ if { [istarget "s390x*-*-*"] && [gas_sframe_check] } then { run_dump_test "cfi-sframe-s390x-2" run_dump_test "cfi-sframe-s390x-3" run_dump_test "cfi-sframe-s390x-err-3" - run_dump_test "cfi-sframe-s390x-err-4" run_dump_test "cfi-sframe-s390x-fpra-offset-1" run_dump_test "cfi-sframe-s390x-fpra-offset-2" run_dump_test "cfi-sframe-s390x-fpra-register-1" run_dump_test "cfi-sframe-s390x-fpra-register-2" + run_dump_test "cfi-sframe-s390x-sp-register" run_dump_test "cfi-sframe-s390x-ra-undefined-1" run_dump_test "cfi-sframe-s390x-pr33756" run_dump_test "cfi-sframe-s390x-non-spfp-cfa-1"