linux/arch/riscv/kernel/vdso
Guo Ren 0715372a06
riscv: compat: vdso: Add COMPAT_VDSO base code implementation
There is no vgettimeofday supported in rv32 that makes simple to
generate rv32 vdso code which only needs riscv64 compiler. Other
architectures need change compiler or -m (machine parameter) to
support vdso32 compiling. If rv32 support vgettimeofday (which
cause C compile) in future, we would add CROSS_COMPILE to support
that makes more requirement on compiler enviornment.

linux-rv64/arch/riscv/kernel/compat_vdso/compat_vdso.so.dbg:
file format elf64-littleriscv

Disassembly of section .text:

0000000000000800 <__vdso_rt_sigreturn>:
 800:   08b00893                li      a7,139
 804:   00000073                ecall
 808:   0000                    unimp
        ...

000000000000080c <__vdso_getcpu>:
 80c:   0a800893                li      a7,168
 810:   00000073                ecall
 814:   8082                    ret
        ...

0000000000000818 <__vdso_flush_icache>:
 818:   10300893                li      a7,259
 81c:   00000073                ecall
 820:   8082                    ret

linux-rv32/arch/riscv/kernel/vdso/vdso.so.dbg:
file format elf32-littleriscv

Disassembly of section .text:

00000800 <__vdso_rt_sigreturn>:
 800:   08b00893                li      a7,139
 804:   00000073                ecall
 808:   0000                    unimp
        ...

0000080c <__vdso_getcpu>:
 80c:   0a800893                li      a7,168
 810:   00000073                ecall
 814:   8082                    ret
        ...

00000818 <__vdso_flush_icache>:
 818:   10300893                li      a7,259
 81c:   00000073                ecall
 820:   8082                    ret

Finally, reuse all *.S from vdso in compat_vdso that makes
implementation clear and readable.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20220405071314.3225832-17-guoren@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-04-26 13:36:53 -07:00
..
.gitignore RISC-V: Fix the VDSO symbol generaton for binutils-2.35+ 2020-11-06 00:03:48 -08:00
flush_icache.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 286 2019-06-05 17:36:37 +02:00
gen_vdso_offsets.sh riscv: explicitly use symbol offsets for VDSO 2021-08-24 21:45:47 -07:00
getcpu.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 286 2019-06-05 17:36:37 +02:00
Makefile riscv: explicitly use symbol offsets for VDSO 2021-08-24 21:45:47 -07:00
note.S riscv: add Linux note to vdso 2020-05-04 14:22:34 -07:00
rt_sigreturn.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 286 2019-06-05 17:36:37 +02:00
vdso.lds.S riscv/vdso: Add support for time namespaces 2021-10-04 14:16:43 -07:00
vdso.S riscv: compat: vdso: Add COMPAT_VDSO base code implementation 2022-04-26 13:36:53 -07:00
vgettimeofday.c riscv: Add extern declarations for vDSO time-related functions 2020-06-25 15:15:51 -07:00