Commit 18efd0b1 authored by Xi Ruoyao's avatar Xi Ruoyao Committed by Jason A. Donenfeld
Browse files

LoongArch: vDSO: Wire up getrandom() vDSO implementation 



Hook up the generic vDSO implementation to the LoongArch vDSO data page
by providing the required __arch_chacha20_blocks_nostack,
__arch_get_k_vdso_rng_data, and getrandom_syscall implementations. Also
wire up the selftests.

Signed-off-by: default avatarXi Ruoyao <xry111@xry111.site>
Acked-by: default avatarHuacai Chen <chenhuacai@kernel.org>
Signed-off-by: default avatarJason A. Donenfeld <Jason@zx2c4.com>
parent 4d456f0c

arch/loongarch/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -190,6 +190,7 @@ config LOONGARCH 
	select TRACE_IRQFLAGS_SUPPORT

	select USE_PERCPU_NUMA_NODE_ID

	select USER_STACKTRACE_SUPPORT

	select VDSO_GETRANDOM

	select ZONE_DMA32



config 32BIT

arch/loongarch/include/asm/vdso/getrandom.h

0 → 100644
+39 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

/*

 * Copyright (C) 2024 Xi Ruoyao <xry111@xry111.site>. All Rights Reserved.

 */

#ifndef __ASM_VDSO_GETRANDOM_H

#define __ASM_VDSO_GETRANDOM_H



#ifndef __ASSEMBLY__



#include <asm/unistd.h>

#include <asm/vdso/vdso.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(

	"      syscall 0\n"

	: "+r" (ret)

	: "r" (nr), "r" (buffer), "r" (len), "r" (flags)

	: "$t0", "$t1", "$t2", "$t3", "$t4", "$t5", "$t6", "$t7", "$t8",

	  "memory");



	return ret;

}



static __always_inline const struct vdso_rng_data *__arch_get_vdso_rng_data(void)

{

	return (const struct vdso_rng_data *)(get_vdso_data() + VVAR_LOONGARCH_PAGES_START *

	       PAGE_SIZE + offsetof(struct loongarch_vdso_data, rng_data));

}



#endif /* !__ASSEMBLY__ */



#endif /* __ASM_VDSO_GETRANDOM_H */

arch/loongarch/include/asm/vdso/vdso.h

+6 −0
Original line number Diff line number Diff line
@@ -4,6 +4,9 @@ 
 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited

 */



#ifndef _ASM_VDSO_VDSO_H

#define _ASM_VDSO_VDSO_H



#ifndef __ASSEMBLY__



#include <asm/asm.h>
@@ -16,6 +19,7 @@ struct vdso_pcpu_data { 


struct loongarch_vdso_data {

	struct vdso_pcpu_data pdata[NR_CPUS];

	struct vdso_rng_data rng_data;

};



/*
@@ -63,3 +67,5 @@ static inline unsigned long get_vdso_data(void) 
}



#endif /* __ASSEMBLY__ */



#endif

arch/loongarch/include/asm/vdso/vsyscall.h

+8 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
#include <vdso/datapage.h>



extern struct vdso_data *vdso_data;

extern struct vdso_rng_data *vdso_rng_data;



/*

 * Update the vDSO data page to keep in sync with kernel timekeeping.
@@ -19,6 +20,13 @@ struct vdso_data *__loongarch_get_k_vdso_data(void) 
}

#define __arch_get_k_vdso_data __loongarch_get_k_vdso_data



static __always_inline

struct vdso_rng_data *__loongarch_get_k_vdso_rng_data(void)

{

	return vdso_rng_data;

}

#define __arch_get_k_vdso_rng_data __loongarch_get_k_vdso_rng_data



/* The asm-generic header needs to be included after the definitions above */

#include <asm-generic/vdso/vsyscall.h>

arch/loongarch/kernel/vdso.c

+1 −0
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ static union { 
static struct page *vdso_pages[] = { NULL };

struct vdso_data *vdso_data = generic_vdso_data.data;

struct vdso_pcpu_data *vdso_pdata = loongarch_vdso_data.vdata.pdata;

struct vdso_rng_data *vdso_rng_data = &loongarch_vdso_data.vdata.rng_data;



static int vdso_mremap(const struct vm_special_mapping *sm, struct vm_area_struct *new_vma)

{