From: Richard Henderson <richard.henderson@linaro.org>
To: Vineet Gupta <vineetg@rivosinc.com>, qemu-devel@nongnu.org
Cc: "Alistair Francis" <alistair.francis@wdc.com>,
"Philippe Mathieu-Daudé" <philmd@linaro.org>,
"Edwin Lu" <ewlu@rivosinc.com>,
gnu-toolchain <gnu-toolchain@rivosinc.com>
Subject: Re: [PULL 15/21] linux-user/riscv: Add vdso
Date: Sat, 13 Jan 2024 08:35:39 +1100 [thread overview]
Message-ID: <119848b9-0cd7-4d33-bc43-385c86069388@linaro.org> (raw)
In-Reply-To: <d5265d3a-7df7-4f93-93c4-a5d3a6251372@rivosinc.com>
On 1/12/24 08:49, Vineet Gupta wrote:
> Hi Richard, Alistair
>
> On 10/30/23 14:17, Richard Henderson wrote:
>> diff --git a/linux-user/riscv/Makefile.vdso b/linux-user/riscv/Makefile.vdso
>> new file mode 100644
>> index 0000000000..2c257dbfda
>> --- /dev/null
>> +++ b/linux-user/riscv/Makefile.vdso
>> @@ -0,0 +1,15 @@
>> +include $(BUILD_DIR)/tests/tcg/riscv64-linux-user/config-target.mak
>> +
>> +SUBDIR = $(SRC_PATH)/linux-user/riscv
>> +VPATH += $(SUBDIR)
>> +
>> +all: $(SUBDIR)/vdso-32.so $(SUBDIR)/vdso-64.so
>> +
>> +LDFLAGS = -nostdlib -shared -fpic -Wl,-h,linux-vdso.so.1 -Wl,--build-id=sha1 \
>> + -Wl,--hash-style=both -Wl,-T,$(SUBDIR)/vdso.ld
>> +
>> +$(SUBDIR)/vdso-32.so: vdso.S vdso.ld vdso-asmoffset.h
>> + $(CC) -o $@ $(LDFLAGS) -mabi=ilp32d -march=rv32g $<
>> +
>> +$(SUBDIR)/vdso-64.so: vdso.S vdso.ld vdso-asmoffset.h
>> + $(CC) -o $@ $(LDFLAGS) -mabi=lp64d -march=rv64g $<
>
> So by default qemu ships the vdso binary. How can one rebuild it ?
>
> From skimming the build files it seems following ought to do it
> make update-linux-vdso
>
> with a prior configure cmd like below with PATH pointing to the cross
> compiler.
> ../configure --target-list=riscv64-linux-user
> --cross-cc-riscv64=riscv64-unknown-linux-gnu-gcc
Yes, that should do it.
> But it doesn't, I'm sure we are missing something basis here.
Do you get an error message?
Did $(BUILD_DIR)/tests/tcg/riscv64-linux-user/config-target.mak get created properly?
> For starters we saw something that seems like a thinko in
>
> diff --git a/linux-user/riscv/vdso.S b/linux-user/riscv/vdso.S
> -#define sizeof_reg (__riscv_xlen / 4)
> +#define sizeof_reg (__riscv_xlen / 8)
Oops.
> As as aside, we also see that rt_sigreturn in kernel vdso elides the
> explicit the call frame information. Again we naively don't know if that
> is required in qemu.
>
> .text
> ENTRY(__vdso_rt_sigreturn)
> .cfi_startproc
> .cfi_signal_frame
> li a7, __NR_rt_sigreturn
> ecall
> .cfi_endproc
> ENDPROC(__vdso_rt_sigreturn)
Perhaps it's not required, no. But I'd consider the lack of info from the kernel to be a
bug. Lack of it means places like gcc have to have special cases.
r~
next prev parent reply other threads:[~2024-01-12 21:36 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-30 21:17 [PULL 00/21] linux-user patch queue Richard Henderson
2023-10-30 21:17 ` [PULL 01/21] linux-user: Fix guest signal remapping after adjusting SIGABRT Richard Henderson
2023-10-30 21:17 ` [PULL 02/21] linux-user: Introduce imgsrc_read, imgsrc_read_alloc Richard Henderson
2023-10-30 21:17 ` [PULL 03/21] linux-user: Tidy loader_exec Richard Henderson
2023-10-30 21:17 ` [PULL 04/21] linux-user: Do not clobber bprm_buf swapping ehdr Richard Henderson
2023-10-30 21:17 ` [PULL 05/21] linux-user: Use ImageSource in load_elf_image Richard Henderson
2023-10-30 21:17 ` [PULL 06/21] linux-user: Use ImageSource in load_symbols Richard Henderson
2023-10-30 21:17 ` [PULL 07/21] linux-user: Replace bprm->fd with bprm->src.fd Richard Henderson
2023-10-30 21:17 ` [PULL 08/21] linux-user: Load vdso image if available Richard Henderson
2023-10-30 21:17 ` [PULL 09/21] linux-user: Add gen-vdso tool Richard Henderson
2023-11-02 12:49 ` Peter Maydell
2023-10-30 21:17 ` [PULL 10/21] linux-user/i386: Add vdso Richard Henderson
2023-10-30 21:17 ` [PULL 11/21] linux-user/x86_64: " Richard Henderson
2023-10-30 21:17 ` [PULL 12/21] linux-user/aarch64: " Richard Henderson
2023-10-30 21:17 ` [PULL 13/21] linux-user/arm: " Richard Henderson
2023-10-30 21:17 ` [PULL 14/21] linux-user/hppa: " Richard Henderson
2023-10-30 21:17 ` [PULL 15/21] linux-user/riscv: " Richard Henderson
2024-01-11 21:49 ` Vineet Gupta
2024-01-12 21:35 ` Richard Henderson [this message]
2024-01-12 23:04 ` Palmer Dabbelt
2024-01-12 23:37 ` Vineet Gupta
2024-01-12 23:58 ` Vineet Gupta
2024-01-13 0:05 ` Richard Henderson
2024-01-13 0:22 ` Vineet Gupta
2024-01-14 23:52 ` Richard Henderson
2023-10-30 21:17 ` [PULL 16/21] linux-user/loongarch64: " Richard Henderson
2023-10-30 21:17 ` [PULL 17/21] linux-user/ppc: " Richard Henderson
2023-10-30 21:17 ` [PULL 18/21] linux-user/s390x: Rename __SIGNAL_FRAMESIZE to STACK_FRAME_OVERHEAD Richard Henderson
2023-10-30 21:17 ` [PULL 19/21] linux-user/s390x: Add vdso Richard Henderson
2023-10-30 21:17 ` [PULL 20/21] linux-user: Show vdso address in /proc/pid/maps Richard Henderson
2023-10-30 21:17 ` [PULL 21/21] build: Add update-linux-vdso makefile rule Richard Henderson
2023-10-31 7:51 ` [PULL 00/21] linux-user patch queue Stefan Hajnoczi
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