[PATCH] Revert "RISC-V: vDSO: Wire up getrandom() vDSO implementation"
Palmer Dabbelt
palmer at dabbelt.com
Mon Jun 2 10:33:15 PDT 2025
This has been on -next for a bit, but it's broken and there's already a
v2. So I'm reverting it to avoid more rebasing.
This reverts commit 89079520cef65d6da1e864eab4464effe5396e23.
Signed-off-by: Palmer Dabbelt <palmer at dabbelt.com>
---
arch/riscv/Kconfig | 1 -
arch/riscv/include/asm/vdso/getrandom.h | 30 ---
arch/riscv/kernel/vdso/Makefile | 12 -
arch/riscv/kernel/vdso/getrandom.c | 10 -
arch/riscv/kernel/vdso/vdso.lds.S | 1 -
arch/riscv/kernel/vdso/vgetrandom-chacha.S | 244 ------------------
.../selftests/vDSO/vgetrandom-chacha.S | 2 -
7 files changed, 300 deletions(-)
delete mode 100644 arch/riscv/include/asm/vdso/getrandom.h
delete mode 100644 arch/riscv/kernel/vdso/getrandom.c
delete mode 100644 arch/riscv/kernel/vdso/vgetrandom-chacha.S
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index fbca724302ab..bbec87b79309 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -218,7 +218,6 @@ config RISCV
select THREAD_INFO_IN_TASK
select TRACE_IRQFLAGS_SUPPORT
select UACCESS_MEMCPY if !MMU
- select VDSO_GETRANDOM if HAVE_GENERIC_VDSO
select USER_STACKTRACE_SUPPORT
select ZONE_DMA32 if 64BIT
diff --git a/arch/riscv/include/asm/vdso/getrandom.h b/arch/riscv/include/asm/vdso/getrandom.h
deleted file mode 100644
index 8dc92441702a..000000000000
--- a/arch/riscv/include/asm/vdso/getrandom.h
+++ /dev/null
@@ -1,30 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Copyright (C) 2025 Xi Ruoyao <xry111 at xry111.site>. All Rights Reserved.
- */
-#ifndef __ASM_VDSO_GETRANDOM_H
-#define __ASM_VDSO_GETRANDOM_H
-
-#ifndef __ASSEMBLY__
-
-#include <asm/unistd.h>
-
-static __always_inline ssize_t getrandom_syscall(void *_buffer, size_t _len, unsigned int _flags)
-{
- register long ret asm("a0");
- register long nr asm("a7") = __NR_getrandom;
- register void *buffer asm("a0") = _buffer;
- register size_t len asm("a1") = _len;
- register unsigned int flags asm("a2") = _flags;
-
- asm volatile ("ecall\n"
- : "+r" (ret)
- : "r" (nr), "r" (buffer), "r" (len), "r" (flags)
- : "memory");
-
- return ret;
-}
-
-#endif /* !__ASSEMBLY__ */
-
-#endif /* __ASM_VDSO_GETRANDOM_H */
diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile
index 8d12f5646eb5..4a5d131506fc 100644
--- a/arch/riscv/kernel/vdso/Makefile
+++ b/arch/riscv/kernel/vdso/Makefile
@@ -13,17 +13,9 @@ vdso-syms += flush_icache
vdso-syms += hwprobe
vdso-syms += sys_hwprobe
-ifdef CONFIG_VDSO_GETRANDOM
-vdso-syms += getrandom
-endif
-
# Files to link into the vdso
obj-vdso = $(patsubst %, %.o, $(vdso-syms)) note.o
-ifdef CONFIG_VDSO_GETRANDOM
-obj-vdso += vgetrandom-chacha.o
-endif
-
ccflags-y := -fno-stack-protector
ccflags-y += -DDISABLE_BRANCH_PROFILING
ccflags-y += -fno-builtin
@@ -32,10 +24,6 @@ ifneq ($(c-gettimeofday-y),)
CFLAGS_vgettimeofday.o += -fPIC -include $(c-gettimeofday-y)
endif
-ifneq ($(c-getrandom-y),)
- CFLAGS_getrandom.o += -fPIC -include $(c-getrandom-y)
-endif
-
CFLAGS_hwprobe.o += -fPIC
# Build rules
diff --git a/arch/riscv/kernel/vdso/getrandom.c b/arch/riscv/kernel/vdso/getrandom.c
deleted file mode 100644
index f21922e8cebd..000000000000
--- a/arch/riscv/kernel/vdso/getrandom.c
+++ /dev/null
@@ -1,10 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Copyright (C) 2025 Xi Ruoyao <xry111 at xry111.site>. All Rights Reserved.
- */
-#include <linux/types.h>
-
-ssize_t __vdso_getrandom(void *buffer, size_t len, unsigned int flags, void *opaque_state, size_t opaque_len)
-{
- return __cvdso_getrandom(buffer, len, flags, opaque_state, opaque_len);
-}
diff --git a/arch/riscv/kernel/vdso/vdso.lds.S b/arch/riscv/kernel/vdso/vdso.lds.S
index abc69cda0445..8e86965a8aae 100644
--- a/arch/riscv/kernel/vdso/vdso.lds.S
+++ b/arch/riscv/kernel/vdso/vdso.lds.S
@@ -80,7 +80,6 @@ VERSION
#ifndef COMPAT_VDSO
__vdso_riscv_hwprobe;
#endif
- __vdso_getrandom;
local: *;
};
}
diff --git a/arch/riscv/kernel/vdso/vgetrandom-chacha.S b/arch/riscv/kernel/vdso/vgetrandom-chacha.S
deleted file mode 100644
index d793cadc78a6..000000000000
--- a/arch/riscv/kernel/vdso/vgetrandom-chacha.S
+++ /dev/null
@@ -1,244 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * Copyright (C) 2025 Xi Ruoyao <xry111 at xry111.site>. All Rights Reserved.
- *
- * Based on arch/loongarch/vdso/vgetrandom-chacha.S.
- */
-
-#include <asm/asm.h>
-#include <linux/linkage.h>
-
-.text
-
-.macro ROTRI rd rs imm
- slliw t0, \rs, 32 - \imm
- srliw \rd, \rs, \imm
- or \rd, \rd, t0
-.endm
-
-.macro OP_4REG op d0 d1 d2 d3 s0 s1 s2 s3
- \op \d0, \d0, \s0
- \op \d1, \d1, \s1
- \op \d2, \d2, \s2
- \op \d3, \d3, \s3
-.endm
-
-/*
- * a0: output bytes
- * a1: 32-byte key input
- * a2: 8-byte counter input/output
- * a3: number of 64-byte blocks to write to output
- */
-SYM_FUNC_START(__arch_chacha20_blocks_nostack)
-
-#define output a0
-#define key a1
-#define counter a2
-#define nblocks a3
-#define i a4
-#define state0 s0
-#define state1 s1
-#define state2 s2
-#define state3 s3
-#define state4 s4
-#define state5 s5
-#define state6 s6
-#define state7 s7
-#define state8 s8
-#define state9 s9
-#define state10 s10
-#define state11 s11
-#define state12 a5
-#define state13 a6
-#define state14 a7
-#define state15 t1
-#define cnt t2
-#define copy0 t3
-#define copy1 t4
-#define copy2 t5
-#define copy3 t6
-
-/* Packs to be used with OP_4REG */
-#define line0 state0, state1, state2, state3
-#define line1 state4, state5, state6, state7
-#define line2 state8, state9, state10, state11
-#define line3 state12, state13, state14, state15
-
-#define line1_perm state5, state6, state7, state4
-#define line2_perm state10, state11, state8, state9
-#define line3_perm state15, state12, state13, state14
-
-#define copy copy0, copy1, copy2, copy3
-
-#define _16 16, 16, 16, 16
-#define _20 20, 20, 20, 20
-#define _24 24, 24, 24, 24
-#define _25 25, 25, 25, 25
-
- addi sp, sp, -12*SZREG
- REG_S s0, (sp)
- REG_S s1, SZREG(sp)
- REG_S s2, 2*SZREG(sp)
- REG_S s3, 3*SZREG(sp)
- REG_S s4, 4*SZREG(sp)
- REG_S s5, 5*SZREG(sp)
- REG_S s6, 6*SZREG(sp)
- REG_S s7, 7*SZREG(sp)
- REG_S s8, 8*SZREG(sp)
- REG_S s9, 9*SZREG(sp)
- REG_S s10, 10*SZREG(sp)
- REG_S s11, 11*SZREG(sp)
-
- ld cnt, (counter)
-
- li copy0, 0x61707865
- li copy1, 0x3320646e
- li copy2, 0x79622d32
- li copy3, 0x6b206574
-
-.Lblock:
- /* state[0,1,2,3] = "expand 32-byte k" */
- mv state0, copy0
- mv state1, copy1
- mv state2, copy2
- mv state3, copy3
-
- /* state[4,5,..,11] = key */
- lw state4, (key)
- lw state5, 4(key)
- lw state6, 8(key)
- lw state7, 12(key)
- lw state8, 16(key)
- lw state9, 20(key)
- lw state10, 24(key)
- lw state11, 28(key)
-
- /* state[12,13] = counter */
- mv state12, cnt
- srli state13, cnt, 32
-
- /* state[14,15] = 0 */
- mv state14, zero
- mv state15, zero
-
- li i, 10
-.Lpermute:
- /* odd round */
- OP_4REG addw line0, line1
- OP_4REG xor line3, line0
- OP_4REG ROTRI line3, _16
-
- OP_4REG addw line2, line3
- OP_4REG xor line1, line2
- OP_4REG ROTRI line1, _20
-
- OP_4REG addw line0, line1
- OP_4REG xor line3, line0
- OP_4REG ROTRI line3, _24
-
- OP_4REG addw line2, line3
- OP_4REG xor line1, line2
- OP_4REG ROTRI line1, _25
-
- /* even round */
- OP_4REG addw line0, line1_perm
- OP_4REG xor line3_perm, line0
- OP_4REG ROTRI line3_perm, _16
-
- OP_4REG addw line2_perm, line3_perm
- OP_4REG xor line1_perm, line2_perm
- OP_4REG ROTRI line1_perm, _20
-
- OP_4REG addw line0, line1_perm
- OP_4REG xor line3_perm, line0
- OP_4REG ROTRI line3_perm, _24
-
- OP_4REG addw line2_perm, line3_perm
- OP_4REG xor line1_perm, line2_perm
- OP_4REG ROTRI line1_perm, _25
-
- addi i, i, -1
- bnez i, .Lpermute
-
- /* output[0,1,2,3] = copy[0,1,2,3] + state[0,1,2,3] */
- OP_4REG addw line0, copy
- sw state0, (output)
- sw state1, 4(output)
- sw state2, 8(output)
- sw state3, 12(output)
-
- /* from now on state[0,1,2,3] are scratch registers */
-
- /* state[0,1,2,3] = lo(key) */
- lw state0, (key)
- lw state1, 4(key)
- lw state2, 8(key)
- lw state3, 12(key)
-
- /* output[4,5,6,7] = state[0,1,2,3] + state[4,5,6,7] */
- OP_4REG addw line1, line0
- sw state4, 16(output)
- sw state5, 20(output)
- sw state6, 24(output)
- sw state7, 28(output)
-
- /* state[0,1,2,3] = hi(key) */
- lw state0, 16(key)
- lw state1, 20(key)
- lw state2, 24(key)
- lw state3, 28(key)
-
- /* output[8,9,10,11] = tmp[0,1,2,3] + state[8,9,10,11] */
- OP_4REG addw line2, line0
- sw state8, 32(output)
- sw state9, 36(output)
- sw state10, 40(output)
- sw state11, 44(output)
-
- /* output[12,13,14,15] = state[12,13,14,15] + [cnt_lo, cnt_hi, 0, 0] */
- addw state12, state12, cnt
- srli state0, cnt, 32
- addw state13, state13, state0
- sw state12, 48(output)
- sw state13, 52(output)
- sw state14, 56(output)
- sw state15, 60(output)
-
- /* ++counter */
- addi cnt, cnt, 1
-
- /* output += 64 */
- addi output, output, 64
- /* --nblocks */
- addi nblocks, nblocks, -1
- bnez nblocks, .Lblock
-
- /* counter = [cnt_lo, cnt_hi] */
- sd cnt, (counter)
-
- /* Zero out the potentially sensitive regs, in case nothing uses these
- * again. As at now copy[0,1,2,3] just contains "expand 32-byte k" and
- * state[0,...,11] are s0-s11 those we'll restore in the epilogue, we
- * only need to zero state[12,...,15].
- */
- mv state12, zero
- mv state13, zero
- mv state14, zero
- mv state15, zero
-
- REG_L s0, (sp)
- REG_L s1, SZREG(sp)
- REG_L s2, 2*SZREG(sp)
- REG_L s3, 3*SZREG(sp)
- REG_L s4, 4*SZREG(sp)
- REG_L s5, 5*SZREG(sp)
- REG_L s6, 6*SZREG(sp)
- REG_L s7, 7*SZREG(sp)
- REG_L s8, 8*SZREG(sp)
- REG_L s9, 9*SZREG(sp)
- REG_L s10, 10*SZREG(sp)
- REG_L s11, 11*SZREG(sp)
- addi sp, sp, 12*SZREG
-
- ret
-SYM_FUNC_END(__arch_chacha20_blocks_nostack)
diff --git a/tools/testing/selftests/vDSO/vgetrandom-chacha.S b/tools/testing/selftests/vDSO/vgetrandom-chacha.S
index a4a82e1c28a9..d6e09af7c0a9 100644
--- a/tools/testing/selftests/vDSO/vgetrandom-chacha.S
+++ b/tools/testing/selftests/vDSO/vgetrandom-chacha.S
@@ -11,8 +11,6 @@
#include "../../../../arch/loongarch/vdso/vgetrandom-chacha.S"
#elif defined(__powerpc__) || defined(__powerpc64__)
#include "../../../../arch/powerpc/kernel/vdso/vgetrandom-chacha.S"
-#elif defined(__riscv) && __riscv_xlen == 64
-#include "../../../../arch/riscv/kernel/vdso/vgetrandom-chacha.S"
#elif defined(__s390x__)
#include "../../../../arch/s390/kernel/vdso64/vgetrandom-chacha.S"
#elif defined(__x86_64__)
--
2.39.5 (Apple Git-154)
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