From: Ben Dooks <ben.dooks@codethink.co.uk> To: linux-kernel@lists.codethink.co.uk, linux-riscv@lists.infradead.org Cc: palmer@dabbelt.com, aou@eecs.berkeley.edu, linux-kernel@vger.kernel.org, Ben Dooks <ben.dooks@codethink.co.uk>, Bin Meng <bmeng.cn@gmail.com> Subject: [PATCH] [PATCH v2] riscv: add as-options for modules with assembly compontents Date: Sun, 29 May 2022 16:22:00 +0100 [thread overview] Message-ID: <20220529152200.609809-1-ben.dooks@codethink.co.uk> (raw) When trying to load modules built for RISC-V which include assembly files the kernel loader errors with "unexpected relocation type 'R_RISCV_ALIGN'" due to R_RISCV_ALIGN relocations being generated by the assembler. The R_RISCV_ALIGN relocations can be removed at the expense of code space by adding -mno-relax to gcc and as. In commit 7a8e7da42250138 ("RISC-V: Fixes to module loading") -mno-relax is added to the build variable KBUILD_CFLAGS_MODULE. See [1] for more info. The issue is that when kbuild builds a .S file, it invokes gcc with the -mno-relax flag, but this is not being passed through to the assembler. Adding -Wa,-mno-relax to KBUILD_AFLAGS_MODULE ensures that the assembler is invoked correctly. This may have now been fixed in gcc[2] and this addition should not stop newer gcc and as from working. [1] https://github.com/riscv/riscv-elf-psabi-doc/issues/183 [2] https://github.com/gcc-mirror/gcc/commit/3b0a7d624e64eeb81e4d5e8c62c46d86ef521857 Notes: Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> --- arch/riscv/Makefile | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile index 1f5c03082976..fca40511a8c6 100644 --- a/arch/riscv/Makefile +++ b/arch/riscv/Makefile @@ -60,6 +60,7 @@ ifeq ($(CONFIG_PERF_EVENTS),y) endif KBUILD_CFLAGS_MODULE += $(call cc-option,-mno-relax) +KBUILD_AFLAGS_MODULE += $(call as-option,-Wa$(comma)-mno-relax) # GCC versions that support the "-mstrict-align" option default to allowing # unaligned accesses. While unaligned accesses are explicitly allowed in the -- 2.35.1 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv
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From: Ben Dooks <ben.dooks@codethink.co.uk> To: linux-kernel@lists.codethink.co.uk, linux-riscv@lists.infradead.org Cc: palmer@dabbelt.com, aou@eecs.berkeley.edu, linux-kernel@vger.kernel.org, Ben Dooks <ben.dooks@codethink.co.uk>, Bin Meng <bmeng.cn@gmail.com> Subject: [PATCH] [PATCH v2] riscv: add as-options for modules with assembly compontents Date: Sun, 29 May 2022 16:22:00 +0100 [thread overview] Message-ID: <20220529152200.609809-1-ben.dooks@codethink.co.uk> (raw) When trying to load modules built for RISC-V which include assembly files the kernel loader errors with "unexpected relocation type 'R_RISCV_ALIGN'" due to R_RISCV_ALIGN relocations being generated by the assembler. The R_RISCV_ALIGN relocations can be removed at the expense of code space by adding -mno-relax to gcc and as. In commit 7a8e7da42250138 ("RISC-V: Fixes to module loading") -mno-relax is added to the build variable KBUILD_CFLAGS_MODULE. See [1] for more info. The issue is that when kbuild builds a .S file, it invokes gcc with the -mno-relax flag, but this is not being passed through to the assembler. Adding -Wa,-mno-relax to KBUILD_AFLAGS_MODULE ensures that the assembler is invoked correctly. This may have now been fixed in gcc[2] and this addition should not stop newer gcc and as from working. [1] https://github.com/riscv/riscv-elf-psabi-doc/issues/183 [2] https://github.com/gcc-mirror/gcc/commit/3b0a7d624e64eeb81e4d5e8c62c46d86ef521857 Notes: Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> --- arch/riscv/Makefile | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile index 1f5c03082976..fca40511a8c6 100644 --- a/arch/riscv/Makefile +++ b/arch/riscv/Makefile @@ -60,6 +60,7 @@ ifeq ($(CONFIG_PERF_EVENTS),y) endif KBUILD_CFLAGS_MODULE += $(call cc-option,-mno-relax) +KBUILD_AFLAGS_MODULE += $(call as-option,-Wa$(comma)-mno-relax) # GCC versions that support the "-mstrict-align" option default to allowing # unaligned accesses. While unaligned accesses are explicitly allowed in the -- 2.35.1
next reply other threads:[~2022-05-29 15:22 UTC|newest] Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-05-29 15:22 Ben Dooks [this message] 2022-05-29 15:22 ` Ben Dooks 2022-07-21 19:53 ` Palmer Dabbelt 2022-07-21 19:53 ` Palmer Dabbelt 2022-07-25 11:38 ` Ben Dooks 2022-07-25 11:42 ` Conor.Dooley -- strict thread matches above, loose matches on Subject: below -- 2021-07-20 14:44 Ben Dooks 2021-07-20 14:44 ` Ben Dooks 2021-08-10 8:49 ` Ben Dooks 2021-08-10 8:49 ` Ben Dooks
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