From 8d485b447b556e18dda658227bc287e1bc831f08 Mon Sep 17 00:00:00 2001
From: Fox Snowpatch <fox@fox.ozlabs.org>
Date: Thu, 22 Aug 2024 07:20:34 +0000
Subject: [PATCH] From patchwork series 420424

https://patchwork.ozlabs.org//project/linuxppc-dev/list/?series=420424
---
 arch/powerpc/Kconfig                          |   1 +
 arch/powerpc/include/asm/asm-compat.h         |   8 +
 arch/powerpc/include/asm/mman.h               |   2 +-
 arch/powerpc/include/asm/vdso/getrandom.h     |  67 ++++
 arch/powerpc/include/asm/vdso/vsyscall.h      |   6 +
 arch/powerpc/include/asm/vdso_datapage.h      |   2 +
 arch/powerpc/kernel/asm-offsets.c             |   1 +
 arch/powerpc/kernel/vdso/Makefile             |  45 ++-
 arch/powerpc/kernel/vdso/getrandom.S          |  58 ++++
 arch/powerpc/kernel/vdso/gettimeofday.S       |  13 -
 arch/powerpc/kernel/vdso/vdso32.lds.S         |   1 +
 arch/powerpc/kernel/vdso/vdso64.lds.S         |   1 +
 arch/powerpc/kernel/vdso/vgetrandom-chacha.S  | 297 ++++++++++++++++++
 arch/powerpc/kernel/vdso/vgetrandom.c         |  14 +
 arch/x86/entry/vdso/vma.c                     |   3 +
 arch/x86/include/asm/pvclock.h                |   1 +
 arch/x86/include/asm/vdso/vsyscall.h          |  10 +-
 drivers/char/random.c                         |   5 +-
 fs/proc/task_mmu.c                            |   4 +-
 include/asm-generic/unaligned.h               |  11 +-
 include/linux/mm.h                            |   4 +-
 include/trace/events/mmflags.h                |   4 +-
 include/vdso/datapage.h                       |   2 +-
 include/vdso/getrandom.h                      |   2 +-
 include/vdso/helpers.h                        |   1 +
 include/vdso/unaligned.h                      |  15 +
 lib/vdso/Makefile                             |   1 +
 lib/vdso/getrandom.c                          |  30 +-
 tools/arch/powerpc/vdso                       |   1 +
 tools/arch/x86/vdso                           |   1 +
 tools/include/linux/linkage.h                 |   4 +
 tools/testing/selftests/vDSO/Makefile         |  12 +-
 tools/testing/selftests/vDSO/vdso_call.h      |  52 +++
 tools/testing/selftests/vDSO/vdso_config.h    |  14 +-
 .../selftests/vDSO/vdso_test_getrandom.c      |  11 +-
 35 files changed, 628 insertions(+), 76 deletions(-)
 create mode 100644 arch/powerpc/include/asm/vdso/getrandom.h
 create mode 100644 arch/powerpc/kernel/vdso/getrandom.S
 create mode 100644 arch/powerpc/kernel/vdso/vgetrandom-chacha.S
 create mode 100644 arch/powerpc/kernel/vdso/vgetrandom.c
 create mode 100644 include/vdso/unaligned.h
 create mode 120000 tools/arch/powerpc/vdso
 create mode 120000 tools/arch/x86/vdso
 create mode 100644 tools/testing/selftests/vDSO/vdso_call.h

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index d7b09b064a8ac..b45452ac4a73b 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -311,6 +311,7 @@ config PPC
 	select SYSCTL_EXCEPTION_TRACE
 	select THREAD_INFO_IN_TASK
 	select TRACE_IRQFLAGS_SUPPORT
+	select VDSO_GETRANDOM
 	#
 	# Please keep this list sorted alphabetically.
 	#
diff --git a/arch/powerpc/include/asm/asm-compat.h b/arch/powerpc/include/asm/asm-compat.h
index 2bc53c646ccd7..6e53a80917ef6 100644
--- a/arch/powerpc/include/asm/asm-compat.h
+++ b/arch/powerpc/include/asm/asm-compat.h
@@ -61,4 +61,12 @@
 
 #endif
 
+#ifdef __BIG_ENDIAN__
+#define LWZX_LE	stringify_in_c(lwbrx)
+#define STWX_LE	stringify_in_c(stwbrx)
+#else
+#define LWZX_LE	stringify_in_c(lwzx)
+#define STWX_LE	stringify_in_c(stwx)
+#endif
+
 #endif /* _ASM_POWERPC_ASM_COMPAT_H */
diff --git a/arch/powerpc/include/asm/mman.h b/arch/powerpc/include/asm/mman.h
index 17a77d47ed6d6..42a51a993d942 100644
--- a/arch/powerpc/include/asm/mman.h
+++ b/arch/powerpc/include/asm/mman.h
@@ -6,7 +6,7 @@
 
 #include <uapi/asm/mman.h>
 
-#ifdef CONFIG_PPC64
+#if defined(CONFIG_PPC64) && !defined(BUILD_VDSO)
 
 #include <asm/cputable.h>
 #include <linux/mm.h>
diff --git a/arch/powerpc/include/asm/vdso/getrandom.h b/arch/powerpc/include/asm/vdso/getrandom.h
new file mode 100644
index 0000000000000..b37e581b02cbb
--- /dev/null
+++ b/arch/powerpc/include/asm/vdso/getrandom.h
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2024 Christophe Leroy <christophe.leroy@csgroup.eu>, CS GROUP France
+ */
+#ifndef _ASM_POWERPC_VDSO_GETRANDOM_H
+#define _ASM_POWERPC_VDSO_GETRANDOM_H
+
+#ifndef __ASSEMBLY__
+
+static __always_inline int do_syscall_3(const unsigned long _r0, const unsigned long _r3,
+					const unsigned long _r4, const unsigned long _r5)
+{
+	register long r0 asm("r0") = _r0;
+	register unsigned long r3 asm("r3") = _r3;
+	register unsigned long r4 asm("r4") = _r4;
+	register unsigned long r5 asm("r5") = _r5;
+	register int ret asm ("r3");
+
+	asm volatile(
+		"       sc\n"
+		"	bns+	1f\n"
+		"	neg	%0, %0\n"
+		"1:\n"
+	: "=r" (ret), "+r" (r4), "+r" (r5), "+r" (r0)
+	: "r" (r3)
+	: "memory", "r6", "r7", "r8", "r9", "r10", "r11", "r12", "cr0", "ctr");
+
+	return ret;
+}
+
+/**
+ * getrandom_syscall - Invoke the getrandom() syscall.
+ * @buffer:	Destination buffer to fill with random bytes.
+ * @len:	Size of @buffer in bytes.
+ * @flags:	Zero or more GRND_* flags.
+ * Returns:	The number of bytes written to @buffer, or a negative value indicating an error.
+ */
+static __always_inline ssize_t getrandom_syscall(void *buffer, size_t len, unsigned int flags)
+{
+	return do_syscall_3(__NR_getrandom, (unsigned long)buffer,
+			    (unsigned long)len, (unsigned long)flags);
+}
+
+static __always_inline struct vdso_rng_data *__arch_get_vdso_rng_data(void)
+{
+	BUILD_BUG();
+}
+
+ssize_t __c_kernel_getrandom(void *buffer, size_t len, unsigned int flags, void *opaque_state,
+			     size_t opaque_len, const struct vdso_rng_data *vd);
+
+/**
+ * __arch_chacha20_blocks_nostack - Generate ChaCha20 stream without using the stack.
+ * @dst_bytes:	Destination buffer to hold @nblocks * 64 bytes of output.
+ * @key:	32-byte input key.
+ * @counter:	8-byte counter, read on input and updated on return.
+ * @nblocks:	Number of blocks to generate.
+ *
+ * Generates a given positive number of blocks of ChaCha20 output with nonce=0, and does not write
+ * to any stack or memory outside of the parameters passed to it, in order to mitigate stack data
+ * leaking into forked child processes.
+ */
+void __arch_chacha20_blocks_nostack(u8 *dst_bytes, const u32 *key, u32 *counter, size_t nblocks);
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* _ASM_POWERPC_VDSO_GETRANDOM_H */
diff --git a/arch/powerpc/include/asm/vdso/vsyscall.h b/arch/powerpc/include/asm/vdso/vsyscall.h
index 48cf23f1e2736..92f480d8cc6dc 100644
--- a/arch/powerpc/include/asm/vdso/vsyscall.h
+++ b/arch/powerpc/include/asm/vdso/vsyscall.h
@@ -17,6 +17,12 @@ struct vdso_data *__arch_get_k_vdso_data(void)
 }
 #define __arch_get_k_vdso_data __arch_get_k_vdso_data
 
+static __always_inline
+struct vdso_rng_data *__arch_get_k_vdso_rng_data(void)
+{
+	return &vdso_data->rng_data;
+}
+
 /* The asm-generic header needs to be included after the definitions above */
 #include <asm-generic/vdso/vsyscall.h>
 
diff --git a/arch/powerpc/include/asm/vdso_datapage.h b/arch/powerpc/include/asm/vdso_datapage.h
index a585c8e538ff0..e17500c5237e9 100644
--- a/arch/powerpc/include/asm/vdso_datapage.h
+++ b/arch/powerpc/include/asm/vdso_datapage.h
@@ -83,6 +83,7 @@ struct vdso_arch_data {
 	__u32 compat_syscall_map[SYSCALL_MAP_SIZE];	/* Map of compat syscalls */
 
 	struct vdso_data data[CS_BASES];
+	struct vdso_rng_data rng_data;
 };
 
 #else /* CONFIG_PPC64 */
@@ -95,6 +96,7 @@ struct vdso_arch_data {
 	__u32 syscall_map[SYSCALL_MAP_SIZE]; /* Map of syscalls */
 	__u32 compat_syscall_map[0];	/* No compat syscalls on PPC32 */
 	struct vdso_data data[CS_BASES];
+	struct vdso_rng_data rng_data;
 };
 
 #endif /* CONFIG_PPC64 */
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 23733282de4d9..eedb2e04c7852 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -335,6 +335,7 @@ int main(void)
 
 	/* datapage offsets for use by vdso */
 	OFFSET(VDSO_DATA_OFFSET, vdso_arch_data, data);
+	OFFSET(VDSO_RNG_DATA_OFFSET, vdso_arch_data, rng_data);
 	OFFSET(CFG_TB_TICKS_PER_SEC, vdso_arch_data, tb_ticks_per_sec);
 #ifdef CONFIG_PPC64
 	OFFSET(CFG_ICACHE_BLOCKSZ, vdso_arch_data, icache_block_size);
diff --git a/arch/powerpc/kernel/vdso/Makefile b/arch/powerpc/kernel/vdso/Makefile
index 1425b6edc66b2..9109677b2f39f 100644
--- a/arch/powerpc/kernel/vdso/Makefile
+++ b/arch/powerpc/kernel/vdso/Makefile
@@ -8,13 +8,11 @@ include $(srctree)/lib/vdso/Makefile
 obj-vdso32 = sigtramp32-32.o gettimeofday-32.o datapage-32.o cacheflush-32.o note-32.o getcpu-32.o
 obj-vdso64 = sigtramp64-64.o gettimeofday-64.o datapage-64.o cacheflush-64.o note-64.o getcpu-64.o
 
+obj-vdso32 += getrandom-32.o vgetrandom-chacha-32.o
+obj-vdso64 += getrandom-64.o vgetrandom-chacha-64.o
+
 ifneq ($(c-gettimeofday-y),)
   CFLAGS_vgettimeofday-32.o += -include $(c-gettimeofday-y)
-  CFLAGS_vgettimeofday-32.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)
-  CFLAGS_vgettimeofday-32.o += $(call cc-option, -fno-stack-protector)
-  CFLAGS_vgettimeofday-32.o += -DDISABLE_BRANCH_PROFILING
-  CFLAGS_vgettimeofday-32.o += -ffreestanding -fasynchronous-unwind-tables
-  CFLAGS_REMOVE_vgettimeofday-32.o = $(CC_FLAGS_FTRACE)
   CFLAGS_REMOVE_vgettimeofday-32.o += -mcmodel=medium -mabi=elfv1 -mabi=elfv2 -mcall-aixdesc
   # This flag is supported by clang for 64-bit but not 32-bit so it will cause
   # an unused command line flag warning for this file.
@@ -22,11 +20,6 @@ ifneq ($(c-gettimeofday-y),)
   CFLAGS_REMOVE_vgettimeofday-32.o += -fno-stack-clash-protection
   endif
   CFLAGS_vgettimeofday-64.o += -include $(c-gettimeofday-y)
-  CFLAGS_vgettimeofday-64.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)
-  CFLAGS_vgettimeofday-64.o += $(call cc-option, -fno-stack-protector)
-  CFLAGS_vgettimeofday-64.o += -DDISABLE_BRANCH_PROFILING
-  CFLAGS_vgettimeofday-64.o += -ffreestanding -fasynchronous-unwind-tables
-  CFLAGS_REMOVE_vgettimeofday-64.o = $(CC_FLAGS_FTRACE)
 # Go prior to 1.16.x assumes r30 is not clobbered by any VDSO code. That used to be true
 # by accident when the VDSO was hand-written asm code, but may not be now that the VDSO is
 # compiler generated. To avoid breaking Go tell GCC not to use r30. Impact on code
@@ -34,6 +27,16 @@ ifneq ($(c-gettimeofday-y),)
   CFLAGS_vgettimeofday-64.o += $(call cc-option, -ffixed-r30)
 endif
 
+ifneq ($(c-getrandom-y),)
+  CFLAGS_vgetrandom-32.o += -include $(c-getrandom-y)
+  CFLAGS_REMOVE_vgetrandom-32.o += -mcmodel=medium -mabi=elfv1 -mabi=elfv2 -mcall-aixdesc
+  ifdef CONFIG_CC_IS_CLANG
+  CFLAGS_REMOVE_vgetrandom-32.o += -fno-stack-clash-protection
+  endif
+  CFLAGS_vgetrandom-64.o += -include $(c-getrandom-y)
+  CFLAGS_vgetrandom-64.o += $(call cc-option, -ffixed-r30)
+endif
+
 # Build rules
 
 ifdef CROSS32_COMPILE
@@ -42,13 +45,19 @@ else
     VDSOCC := $(CC)
 endif
 
-targets := $(obj-vdso32) vdso32.so.dbg vgettimeofday-32.o
+targets := $(obj-vdso32) vdso32.so.dbg vgettimeofday-32.o vgetrandom-32.o
+targets += crtsavres-32.o
 obj-vdso32 := $(addprefix $(obj)/, $(obj-vdso32))
-targets += $(obj-vdso64) vdso64.so.dbg vgettimeofday-64.o
+targets += $(obj-vdso64) vdso64.so.dbg vgettimeofday-64.o vgetrandom-64.o
 obj-vdso64 := $(addprefix $(obj)/, $(obj-vdso64))
 
-ccflags-y := -fno-common -fno-builtin
+ccflags-y := -fno-common -fno-builtin -DBUILD_VDSO
+ccflags-y += $(DISABLE_LATENT_ENTROPY_PLUGIN)
+ccflags-y += $(call cc-option, -fno-stack-protector)
+ccflags-y += -DDISABLE_BRANCH_PROFILING
+ccflags-y += -ffreestanding -fasynchronous-unwind-tables
 ldflags-y := -Wl,--hash-style=both -nostdlib -shared -z noexecstack $(CLANG_FLAGS)
+ccflags-remove-y := $(CC_FLAGS_FTRACE)
 ldflags-$(CONFIG_LD_IS_LLD) += $(call cc-option,--ld-path=$(LD),-fuse-ld=lld)
 ldflags-$(CONFIG_LD_ORPHAN_WARN) += -Wl,--orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
 
@@ -68,20 +77,26 @@ targets += vdso64.lds
 CPPFLAGS_vdso64.lds += -P -C
 
 # link rule for the .so file, .lds has to be first
-$(obj)/vdso32.so.dbg: $(obj)/vdso32.lds $(obj-vdso32) $(obj)/vgettimeofday-32.o FORCE
+$(obj)/vdso32.so.dbg: $(obj)/vdso32.lds $(obj-vdso32) $(obj)/vgettimeofday-32.o $(obj)/vgetrandom-32.o $(obj)/crtsavres-32.o FORCE
 	$(call if_changed,vdso32ld_and_check)
-$(obj)/vdso64.so.dbg: $(obj)/vdso64.lds $(obj-vdso64) $(obj)/vgettimeofday-64.o FORCE
+$(obj)/vdso64.so.dbg: $(obj)/vdso64.lds $(obj-vdso64) $(obj)/vgettimeofday-64.o $(obj)/vgetrandom-64.o FORCE
 	$(call if_changed,vdso64ld_and_check)
 
 # assembly rules for the .S files
 $(obj-vdso32): %-32.o: %.S FORCE
 	$(call if_changed_dep,vdso32as)
+$(obj)/crtsavres-32.o: %-32.o: $(srctree)/arch/powerpc/lib/crtsavres.S FORCE
+	$(call if_changed_dep,vdso32as)
 $(obj)/vgettimeofday-32.o: %-32.o: %.c FORCE
 	$(call if_changed_dep,vdso32cc)
+$(obj)/vgetrandom-32.o: %-32.o: %.c FORCE
+	$(call if_changed_dep,vdso32cc)
 $(obj-vdso64): %-64.o: %.S FORCE
 	$(call if_changed_dep,vdso64as)
 $(obj)/vgettimeofday-64.o: %-64.o: %.c FORCE
 	$(call if_changed_dep,cc_o_c)
+$(obj)/vgetrandom-64.o: %-64.o: %.c FORCE
+	$(call if_changed_dep,cc_o_c)
 
 # Generate VDSO offsets using helper script
 gen-vdso32sym := $(src)/gen_vdso32_offsets.sh
diff --git a/arch/powerpc/kernel/vdso/getrandom.S b/arch/powerpc/kernel/vdso/getrandom.S
new file mode 100644
index 0000000000000..a957cd2b2b036
--- /dev/null
+++ b/arch/powerpc/kernel/vdso/getrandom.S
@@ -0,0 +1,58 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Userland implementation of getrandom() for processes
+ * for use in the vDSO
+ *
+ * Copyright (C) 2024 Christophe Leroy <christophe.leroy@csgroup.eu>, CS GROUP France
+ */
+#include <asm/processor.h>
+#include <asm/ppc_asm.h>
+#include <asm/vdso.h>
+#include <asm/vdso_datapage.h>
+#include <asm/asm-offsets.h>
+#include <asm/unistd.h>
+
+/*
+ * The macro sets two stack frames, one for the caller and one for the callee
+ * because there are no requirement for the caller to set a stack frame when
+ * calling VDSO so it may have omitted to set one, especially on PPC64
+ */
+
+.macro cvdso_call funct
+  .cfi_startproc
+	PPC_STLU	r1, -PPC_MIN_STKFRM(r1)
+  .cfi_adjust_cfa_offset PPC_MIN_STKFRM
+	mflr		r0
+	PPC_STLU	r1, -PPC_MIN_STKFRM(r1)
+  .cfi_adjust_cfa_offset PPC_MIN_STKFRM
+	PPC_STL		r0, PPC_MIN_STKFRM + PPC_LR_STKOFF(r1)
+  .cfi_rel_offset lr, PPC_MIN_STKFRM + PPC_LR_STKOFF
+#ifdef __powerpc64__
+	PPC_STL		r2, PPC_MIN_STKFRM + STK_GOT(r1)
+  .cfi_rel_offset r2, PPC_MIN_STKFRM + STK_GOT
+#endif
+	get_datapage	r8
+	addi		r8, r8, VDSO_RNG_DATA_OFFSET
+	bl		CFUNC(DOTSYM(\funct))
+	PPC_LL		r0, PPC_MIN_STKFRM + PPC_LR_STKOFF(r1)
+#ifdef __powerpc64__
+	PPC_LL		r2, PPC_MIN_STKFRM + STK_GOT(r1)
+  .cfi_restore r2
+#endif
+	cmpwi		r3, 0
+	mtlr		r0
+	addi		r1, r1, 2 * PPC_MIN_STKFRM
+  .cfi_restore lr
+  .cfi_def_cfa_offset 0
+	crclr		so
+	bgelr+
+	crset		so
+	neg		r3, r3
+	blr
+  .cfi_endproc
+.endm
+
+	.text
+V_FUNCTION_BEGIN(__kernel_getrandom)
+	cvdso_call __c_kernel_getrandom
+V_FUNCTION_END(__kernel_getrandom)
diff --git a/arch/powerpc/kernel/vdso/gettimeofday.S b/arch/powerpc/kernel/vdso/gettimeofday.S
index 48fc6658053aa..67254ac9c8bb4 100644
--- a/arch/powerpc/kernel/vdso/gettimeofday.S
+++ b/arch/powerpc/kernel/vdso/gettimeofday.S
@@ -118,16 +118,3 @@ V_FUNCTION_END(__kernel_clock_getres)
 V_FUNCTION_BEGIN(__kernel_time)
 	cvdso_call __c_kernel_time call_time=1
 V_FUNCTION_END(__kernel_time)
-
-/* Routines for restoring integer registers, called by the compiler.  */
-/* Called with r11 pointing to the stack header word of the caller of the */
-/* function, just beyond the end of the integer restore area.  */
-#ifndef __powerpc64__
-_GLOBAL(_restgpr_31_x)
-_GLOBAL(_rest32gpr_31_x)
-	lwz	r0,4(r11)
-	lwz	r31,-4(r11)
-	mtlr	r0
-	mr	r1,r11
-	blr
-#endif
diff --git a/arch/powerpc/kernel/vdso/vdso32.lds.S b/arch/powerpc/kernel/vdso/vdso32.lds.S
index 426e1ccc6971a..71f086a015df0 100644
--- a/arch/powerpc/kernel/vdso/vdso32.lds.S
+++ b/arch/powerpc/kernel/vdso/vdso32.lds.S
@@ -128,6 +128,7 @@ VERSION
 #if defined(CONFIG_PPC64) || !defined(CONFIG_SMP)
 		__kernel_getcpu;
 #endif
+		__kernel_getrandom;
 
 	local: *;
 	};
diff --git a/arch/powerpc/kernel/vdso/vdso64.lds.S b/arch/powerpc/kernel/vdso/vdso64.lds.S
index bda6c8cdd459c..6f88d063aabe0 100644
--- a/arch/powerpc/kernel/vdso/vdso64.lds.S
+++ b/arch/powerpc/kernel/vdso/vdso64.lds.S
@@ -123,6 +123,7 @@ VERSION
 		__kernel_sigtramp_rt64;
 		__kernel_getcpu;
 		__kernel_time;
+		__kernel_getrandom;
 
 	local: *;
 	};
diff --git a/arch/powerpc/kernel/vdso/vgetrandom-chacha.S b/arch/powerpc/kernel/vdso/vgetrandom-chacha.S
new file mode 100644
index 0000000000000..5375bc5807e14
--- /dev/null
+++ b/arch/powerpc/kernel/vdso/vgetrandom-chacha.S
@@ -0,0 +1,297 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2024 Christophe Leroy <christophe.leroy@csgroup.eu>, CS GROUP France
+ */
+
+#include <linux/linkage.h>
+
+#include <asm/ppc_asm.h>
+
+.macro quarterround4 a1 b1 c1 d1 a2 b2 c2 d2 a3 b3 c3 d3 a4 b4 c4 d4
+	add	\a1, \a1, \b1
+	add	\a2, \a2, \b2
+	add	\a3, \a3, \b3
+	add	\a4, \a4, \b4
+	xor	\d1, \d1, \a1
+	xor	\d2, \d2, \a2
+	xor	\d3, \d3, \a3
+	xor	\d4, \d4, \a4
+	rotlwi	\d1, \d1, 16
+	rotlwi	\d2, \d2, 16
+	rotlwi	\d3, \d3, 16
+	rotlwi	\d4, \d4, 16
+	add	\c1, \c1, \d1
+	add	\c2, \c2, \d2
+	add	\c3, \c3, \d3
+	add	\c4, \c4, \d4
+	xor	\b1, \b1, \c1
+	xor	\b2, \b2, \c2
+	xor	\b3, \b3, \c3
+	xor	\b4, \b4, \c4
+	rotlwi	\b1, \b1, 12
+	rotlwi	\b2, \b2, 12
+	rotlwi	\b3, \b3, 12
+	rotlwi	\b4, \b4, 12
+	add	\a1, \a1, \b1
+	add	\a2, \a2, \b2
+	add	\a3, \a3, \b3
+	add	\a4, \a4, \b4
+	xor	\d1, \d1, \a1
+	xor	\d2, \d2, \a2
+	xor	\d3, \d3, \a3
+	xor	\d4, \d4, \a4
+	rotlwi	\d1, \d1, 8
+	rotlwi	\d2, \d2, 8
+	rotlwi	\d3, \d3, 8
+	rotlwi	\d4, \d4, 8
+	add	\c1, \c1, \d1
+	add	\c2, \c2, \d2
+	add	\c3, \c3, \d3
+	add	\c4, \c4, \d4
+	xor	\b1, \b1, \c1
+	xor	\b2, \b2, \c2
+	xor	\b3, \b3, \c3
+	xor	\b4, \b4, \c4
+	rotlwi	\b1, \b1, 7
+	rotlwi	\b2, \b2, 7
+	rotlwi	\b3, \b3, 7
+	rotlwi	\b4, \b4, 7
+.endm
+
+#define QUARTERROUND4(a1,b1,c1,d1,a2,b2,c2,d2,a3,b3,c3,d3,a4,b4,c4,d4) \
+	quarterround4 16+a1 16+b1 16+c1 16+d1 16+a2 16+b2 16+c2 16+d2 \
+		      16+a3 16+b3 16+c3 16+d3 16+a4 16+b4 16+c4 16+d4
+
+/*
+ * Very basic 32 bits implementation of ChaCha20. Produces a given positive number
+ * of blocks of output with a nonce of 0, taking an input key and 8-byte
+ * counter. Importantly does not spill to the stack. Its arguments are:
+ *
+ *	r3: output bytes
+ *	r4: 32-byte key input
+ *	r5: 8-byte counter input/output
+ *	r6: number of 64-byte blocks to write to output
+ *
+ *	r0: counter of blocks (initialised with r6)
+ *	r4: Value '4' after key has been read.
+ *	r6-r13: key
+ *	r14-r15 : counter
+ *	r16-r31 : state
+ */
+SYM_FUNC_START(__arch_chacha20_blocks_nostack)
+#ifdef __powerpc64__
+	std	r14,-144(r1)
+	std	r15,-136(r1)
+	std	r16,-128(r1)
+	std	r17,-120(r1)
+	std	r18,-112(r1)
+	std	r19,-104(r1)
+	std	r20,-96(r1)
+	std	r21,-88(r1)
+	std	r22,-80(r1)
+	std	r23,-72(r1)
+	std	r24,-64(r1)
+	std	r25,-56(r1)
+	std	r26,-48(r1)
+	std	r27,-40(r1)
+	std	r28,-32(r1)
+	std	r29,-24(r1)
+	std	r30,-16(r1)
+	std	r31,-8(r1)
+#else
+	stwu	r1, -96(r1)
+#if defined(CONFIG_CPU_LITTLE_ENDIAN)
+	stw	r14,24(r1)
+	stw	r15,28(r1)
+	stw	r16,32(r1)
+	stw	r17,36(r1)
+	stw	r18,40(r1)
+	stw	r19,44(r1)
+	stw	r20,48(r1)
+	stw	r21,52(r1)
+	stw	r22,56(r1)
+	stw	r23,60(r1)
+	stw	r24,64(r1)
+	stw	r25,68(r1)
+	stw	r26,72(r1)
+	stw	r27,76(r1)
+	stw	r28,80(r1)
+	stw	r29,84(r1)
+	stw	r30,88(r1)
+	stw	r31,92(r1)
+#else
+	stmw	r14, 24(r1)
+#endif
+#endif
+	mr	r0, r6
+
+	li	r31, 4
+
+	LWZX_LE	r6, 0, r4
+	LWZX_LE	r7, r31, r4
+	addi	r4, r4, 8
+	LWZX_LE	r8, 0, r4
+	LWZX_LE	r9, r31, r4
+	addi	r4, r4, 8
+	LWZX_LE	r10, 0, r4
+	LWZX_LE	r11, r31, r4
+	addi	r4, r4, 8
+	LWZX_LE	r12, 0, r4
+	LWZX_LE	r13, r31, r4
+
+	li	r4, 4
+
+	LWZX_LE	r14, 0, r5
+	LWZX_LE	r15, r4, r5
+#ifdef __powerpc64__
+	rldimi	r14, r15, 32, 0
+#endif
+.Lblock:
+	li	r31, 10
+
+	lis	r16, 0x6170
+	lis	r17, 0x3320
+	lis	r18, 0x7962
+	lis	r19, 0x6b20
+	addi	r16, r16, 0x7865
+	addi	r17, r17, 0x646e
+	addi	r18, r18, 0x2d32
+	addi	r19, r19, 0x6574
+
+	mtctr	r31
+
+	mr	r20, r6
+	mr	r21, r7
+	mr	r22, r8
+	mr	r23, r9
+	mr	r24, r10
+	mr	r25, r11
+	mr	r26, r12
+	mr	r27, r13
+
+	mr	r28, r14
+	mr	r29, r15
+	li	r30, 0
+	li	r31, 0
+
+.Lpermute:
+	QUARTERROUND4( 0, 4, 8,12, 1, 5, 9,13, 2, 6,10,14, 3, 7,11,15)
+	QUARTERROUND4( 0, 5,10,15, 1, 6,11,12, 2, 7, 8,13, 3, 4, 9,14)
+
+	bdnz	.Lpermute
+
+	addis	r16, r16, 0x6170
+	addis	r17, r17, 0x3320
+	addis	r18, r18, 0x7962
+	addis	r19, r19, 0x6b20
+	addi	r16, r16, 0x7865
+	addi	r17, r17, 0x646e
+	addi	r18, r18, 0x2d32
+	addi	r19, r19, 0x6574
+
+	add	r20, r20, r6
+	add	r21, r21, r7
+	add	r22, r22, r8
+	add	r23, r23, r9
+	add	r24, r24, r10
+	add	r25, r25, r11
+	add	r26, r26, r12
+	add	r27, r27, r13
+
+	add	r28, r28, r14
+	add	r29, r29, r15
+
+	STWX_LE	r16, 0, r3
+	STWX_LE	r17, r4, r3
+	addi	r3, r3, 8
+	STWX_LE	r18, 0, r3
+	STWX_LE	r19, r4, r3
+	addi	r3, r3, 8
+	STWX_LE	r20, 0, r3
+	STWX_LE	r21, r4, r3
+	addi	r3, r3, 8
+	STWX_LE	r22, 0, r3
+	STWX_LE	r23, r4, r3
+	addi	r3, r3, 8
+	STWX_LE	r24, 0, r3
+	STWX_LE	r25, r4, r3
+	addi	r3, r3, 8
+	STWX_LE	r26, 0, r3
+	STWX_LE	r27, r4, r3
+	addi	r3, r3, 8
+	STWX_LE	r28, 0, r3
+	STWX_LE	r29, r4, r3
+	addi	r3, r3, 8
+	STWX_LE	r30, 0, r3
+	STWX_LE	r31, r4, r3
+	addi	r3, r3, 8
+
+#ifdef __powerpc64__
+	addi	r14, r14, 1
+	srdi	r15, r14, 32
+#else
+	addic	r14, r14, 1
+	addze	r15, r15
+#endif
+
+	subic.	r0, r0, 1	/* subi. can't use r0 as source */
+	bne	.Lblock
+
+	STWX_LE	r14, 0, r5
+	STWX_LE	r15, r4, r5
+
+	li	r6, 0
+	li	r7, 0
+	li	r8, 0
+	li	r9, 0
+	li	r10, 0
+	li	r11, 0
+	li	r12, 0
+	li	r13, 0
+
+#ifdef __powerpc64__
+	ld	r14,-144(r1)
+	ld	r15,-136(r1)
+	ld	r16,-128(r1)
+	ld	r17,-120(r1)
+	ld	r18,-112(r1)
+	ld	r19,-104(r1)
+	ld	r20,-96(r1)
+	ld	r21,-88(r1)
+	ld	r22,-80(r1)
+	ld	r23,-72(r1)
+	ld	r24,-64(r1)
+	ld	r25,-56(r1)
+	ld	r26,-48(r1)
+	ld	r27,-40(r1)
+	ld	r28,-32(r1)
+	ld	r29,-24(r1)
+	ld	r30,-16(r1)
+	ld	r31,-8(r1)
+#else
+#if defined(CONFIG_CPU_LITTLE_ENDIAN)
+	lwz	r14,24(r1)
+	lwz	r15,28(r1)
+	lwz	r16,32(r1)
+	lwz	r17,36(r1)
+	lwz	r18,40(r1)
+	lwz	r19,44(r1)
+	lwz	r20,48(r1)
+	lwz	r21,52(r1)
+	lwz	r22,56(r1)
+	lwz	r23,60(r1)
+	lwz	r24,64(r1)
+	lwz	r25,68(r1)
+	lwz	r26,72(r1)
+	lwz	r27,76(r1)
+	lwz	r28,80(r1)
+	lwz	r29,84(r1)
+	lwz	r30,88(r1)
+	lwz	r31,92(r1)
+#else
+	lmw	r14, 24(r1)
+#endif
+	addi	r1, r1, 96
+#endif
+	blr
+SYM_FUNC_END(__arch_chacha20_blocks_nostack)
diff --git a/arch/powerpc/kernel/vdso/vgetrandom.c b/arch/powerpc/kernel/vdso/vgetrandom.c
new file mode 100644
index 0000000000000..5f855d45fb7bf
--- /dev/null
+++ b/arch/powerpc/kernel/vdso/vgetrandom.c
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Powerpc userspace implementation of getrandom()
+ *
+ * Copyright (C) 2024 Christophe Leroy <christophe.leroy@csgroup.eu>, CS GROUP France
+ */
+#include <linux/time.h>
+#include <linux/types.h>
+
+ssize_t __c_kernel_getrandom(void *buffer, size_t len, unsigned int flags, void *opaque_state,
+			     size_t opaque_len, const struct vdso_rng_data *vd)
+{
+	return __cvdso_getrandom_data(vd, buffer, len, flags, opaque_state, opaque_len);
+}
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index 6d83ceb7f1bad..b8fed8b8b9ccd 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -38,6 +38,9 @@ struct vdso_data *arch_get_vdso_data(void *vvar_page)
 }
 #undef EMIT_VVAR
 
+DEFINE_VVAR(struct vdso_data, _vdso_data);
+DEFINE_VVAR_SINGLE(struct vdso_rng_data, _vdso_rng_data);
+
 unsigned int vclocks_used __read_mostly;
 
 #if defined(CONFIG_X86_64)
diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h
index 0c92db84469db..6e4f8fae3ce9e 100644
--- a/arch/x86/include/asm/pvclock.h
+++ b/arch/x86/include/asm/pvclock.h
@@ -5,6 +5,7 @@
 #include <asm/clocksource.h>
 #include <asm/pvclock-abi.h>
 
+struct timespec64;
 /* some helper functions for xen and kvm pv clock sources */
 u64 pvclock_clocksource_read(struct pvclock_vcpu_time_info *src);
 u64 pvclock_clocksource_read_nowd(struct pvclock_vcpu_time_info *src);
diff --git a/arch/x86/include/asm/vdso/vsyscall.h b/arch/x86/include/asm/vdso/vsyscall.h
index 972415a8be319..67fedf1698b5e 100644
--- a/arch/x86/include/asm/vdso/vsyscall.h
+++ b/arch/x86/include/asm/vdso/vsyscall.h
@@ -9,9 +9,6 @@
 #include <asm/vgtod.h>
 #include <asm/vvar.h>
 
-DEFINE_VVAR(struct vdso_data, _vdso_data);
-DEFINE_VVAR_SINGLE(struct vdso_rng_data, _vdso_rng_data);
-
 /*
  * Update the vDSO data page to keep in sync with kernel timekeeping.
  */
@@ -22,6 +19,13 @@ struct vdso_data *__x86_get_k_vdso_data(void)
 }
 #define __arch_get_k_vdso_data __x86_get_k_vdso_data
 
+static __always_inline
+struct vdso_rng_data *__x86_get_k_vdso_rng_data(void)
+{
+	return &_vdso_rng_data;
+}
+#define __arch_get_k_vdso_rng_data __x86_get_k_vdso_rng_data
+
 /* The asm-generic header needs to be included after the definitions above */
 #include <asm-generic/vdso/vsyscall.h>
 
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 87fe61295ea1f..77968309e2c2a 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -59,6 +59,7 @@
 #ifdef CONFIG_VDSO_GETRANDOM
 #include <vdso/getrandom.h>
 #include <vdso/datapage.h>
+#include <vdso/vsyscall.h>
 #endif
 #include <asm/archrandom.h>
 #include <asm/processor.h>
@@ -282,7 +283,7 @@ static void crng_reseed(struct work_struct *work)
 	 * is ordered with the write above to base_crng.generation. Pairs with
 	 * the smp_rmb() before the syscall in the vDSO code.
 	 */
-	smp_store_release(&_vdso_rng_data.generation, next_gen + 1);
+	smp_store_release(&__arch_get_k_vdso_rng_data()->generation, next_gen + 1);
 #endif
 	if (!static_branch_likely(&crng_is_ready))
 		crng_init = CRNG_READY;
@@ -735,7 +736,7 @@ static void __cold _credit_init_bits(size_t bits)
 			queue_work(system_unbound_wq, &set_ready);
 		atomic_notifier_call_chain(&random_ready_notifier, 0, NULL);
 #ifdef CONFIG_VDSO_GETRANDOM
-		WRITE_ONCE(_vdso_rng_data.is_ready, true);
+		WRITE_ONCE(__arch_get_k_vdso_rng_data()->is_ready, true);
 #endif
 		wake_up_interruptible(&crng_init_wait);
 		kill_fasync(&fasync, SIGIO, POLL_IN);
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 5f171ad7b436b..4a3fe961cbf65 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -987,8 +987,10 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
 #ifdef CONFIG_X86_USER_SHADOW_STACK
 		[ilog2(VM_SHADOW_STACK)] = "ss",
 #endif
-#ifdef CONFIG_64BIT
+#if VM_DROPPABLE != VM_NONE
 		[ilog2(VM_DROPPABLE)] = "dp",
+#endif
+#ifdef CONFIG_64BIT
 		[ilog2(VM_SEALED)] = "sl",
 #endif
 	};
diff --git a/include/asm-generic/unaligned.h b/include/asm-generic/unaligned.h
index a84c64e5f11ec..95acdd70b3b21 100644
--- a/include/asm-generic/unaligned.h
+++ b/include/asm-generic/unaligned.h
@@ -8,16 +8,7 @@
  */
 #include <linux/unaligned/packed_struct.h>
 #include <asm/byteorder.h>
-
-#define __get_unaligned_t(type, ptr) ({						\
-	const struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr);	\
-	__pptr->x;								\
-})
-
-#define __put_unaligned_t(type, val, ptr) do {					\
-	struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr);		\
-	__pptr->x = (val);							\
-} while (0)
+#include <vdso/unaligned.h>
 
 #define get_unaligned(ptr)	__get_unaligned_t(typeof(*(ptr)), (ptr))
 #define put_unaligned(val, ptr) __put_unaligned_t(typeof(*(ptr)), (val), (ptr))
diff --git a/include/linux/mm.h b/include/linux/mm.h
index c4b238a20b76e..865d3e21ee5ef 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -359,7 +359,7 @@ extern unsigned int kobjsize(const void *objp);
 
 #if defined(CONFIG_X86)
 # define VM_PAT		VM_ARCH_1	/* PAT reserves whole VMA at once (x86) */
-#elif defined(CONFIG_PPC)
+#elif defined(CONFIG_PPC64)
 # define VM_SAO		VM_ARCH_1	/* Strong Access Ordering (powerpc) */
 #elif defined(CONFIG_PARISC)
 # define VM_GROWSUP	VM_ARCH_1
@@ -409,6 +409,8 @@ extern unsigned int kobjsize(const void *objp);
 #ifdef CONFIG_64BIT
 #define VM_DROPPABLE_BIT	40
 #define VM_DROPPABLE		BIT(VM_DROPPABLE_BIT)
+#elif defined(CONFIG_PPC32)
+#define VM_DROPPABLE		VM_ARCH_1
 #else
 #define VM_DROPPABLE		VM_NONE
 #endif
diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h
index b63d211bd1415..9820cbfbcb141 100644
--- a/include/trace/events/mmflags.h
+++ b/include/trace/events/mmflags.h
@@ -143,7 +143,7 @@ IF_HAVE_PG_ARCH_X(arch_3)
 
 #if defined(CONFIG_X86)
 #define __VM_ARCH_SPECIFIC_1 {VM_PAT,     "pat"           }
-#elif defined(CONFIG_PPC)
+#elif defined(CONFIG_PPC64)
 #define __VM_ARCH_SPECIFIC_1 {VM_SAO,     "sao"           }
 #elif defined(CONFIG_PARISC)
 #define __VM_ARCH_SPECIFIC_1 {VM_GROWSUP,	"growsup"	}
@@ -165,7 +165,7 @@ IF_HAVE_PG_ARCH_X(arch_3)
 # define IF_HAVE_UFFD_MINOR(flag, name)
 #endif
 
-#ifdef CONFIG_64BIT
+#if VM_DROPPABLE != VM_NONE
 # define IF_HAVE_VM_DROPPABLE(flag, name) {flag, name},
 #else
 # define IF_HAVE_VM_DROPPABLE(flag, name)
diff --git a/include/vdso/datapage.h b/include/vdso/datapage.h
index b85f24cac3f56..00b66a9b57786 100644
--- a/include/vdso/datapage.h
+++ b/include/vdso/datapage.h
@@ -123,7 +123,7 @@ struct vdso_data {
  * @is_ready:	boolean signaling whether the RNG is initialized
  */
 struct vdso_rng_data {
-	u64	generation;
+	unsigned long	generation;
 	u8	is_ready;
 };
 
diff --git a/include/vdso/getrandom.h b/include/vdso/getrandom.h
index a8b7c14b0ae0a..36fd166bf3306 100644
--- a/include/vdso/getrandom.h
+++ b/include/vdso/getrandom.h
@@ -38,7 +38,7 @@ struct vgetrandom_state {
 		};
 		u8		batch_key[CHACHA_BLOCK_SIZE * 2];
 	};
-	u64			generation;
+	unsigned long		generation;
 	u8			pos;
 	bool 			in_use;
 };
diff --git a/include/vdso/helpers.h b/include/vdso/helpers.h
index 73501149439dd..3ddb03bb05cbe 100644
--- a/include/vdso/helpers.h
+++ b/include/vdso/helpers.h
@@ -4,6 +4,7 @@
 
 #ifndef __ASSEMBLY__
 
+#include <asm/barrier.h>
 #include <vdso/datapage.h>
 
 static __always_inline u32 vdso_read_begin(const struct vdso_data *vd)
diff --git a/include/vdso/unaligned.h b/include/vdso/unaligned.h
new file mode 100644
index 0000000000000..eee3d2a4dbe4d
--- /dev/null
+++ b/include/vdso/unaligned.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __VDSO_UNALIGNED_H
+#define __VDSO_UNALIGNED_H
+
+#define __get_unaligned_t(type, ptr) ({						\
+	const struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr);	\
+	__pptr->x;								\
+})
+
+#define __put_unaligned_t(type, val, ptr) do {					\
+	struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr);		\
+	__pptr->x = (val);							\
+} while (0)
+
+#endif /* __VDSO_UNALIGNED_H */
diff --git a/lib/vdso/Makefile b/lib/vdso/Makefile
index 9f031eafc4651..cedbf15f80874 100644
--- a/lib/vdso/Makefile
+++ b/lib/vdso/Makefile
@@ -4,6 +4,7 @@ GENERIC_VDSO_MK_PATH := $(abspath $(lastword $(MAKEFILE_LIST)))
 GENERIC_VDSO_DIR := $(dir $(GENERIC_VDSO_MK_PATH))
 
 c-gettimeofday-$(CONFIG_GENERIC_GETTIMEOFDAY) := $(addprefix $(GENERIC_VDSO_DIR), gettimeofday.c)
+c-getrandom-$(CONFIG_VDSO_GETRANDOM) := $(addprefix $(GENERIC_VDSO_DIR), getrandom.c)
 
 # This cmd checks that the vdso library does not contain dynamic relocations.
 # It has to be called after the linking of the vdso library and requires it
diff --git a/lib/vdso/getrandom.c b/lib/vdso/getrandom.c
index b230f0b10832f..4a56f45141b49 100644
--- a/lib/vdso/getrandom.c
+++ b/lib/vdso/getrandom.c
@@ -3,15 +3,14 @@
  * Copyright (C) 2022-2024 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
  */
 
-#include <linux/cache.h>
-#include <linux/kernel.h>
-#include <linux/time64.h>
+#include <linux/minmax.h>
+#include <linux/array_size.h>
 #include <vdso/datapage.h>
 #include <vdso/getrandom.h>
+#include <vdso/unaligned.h>
 #include <asm/vdso/getrandom.h>
-#include <asm/vdso/vsyscall.h>
-#include <asm/unaligned.h>
 #include <uapi/linux/mman.h>
+#include <uapi/linux/random.h>
 
 #define MEMCPY_AND_ZERO_SRC(type, dst, src, len) do {				\
 	while (len >= sizeof(type)) {						\
@@ -23,6 +22,9 @@
 	}									\
 } while (0)
 
+#define _PAGE_SIZE (1UL << CONFIG_PAGE_SHIFT)
+#define _PAGE_MASK (~(_PAGE_SIZE - 1))
+
 static void memcpy_and_zero_src(void *dst, void *src, size_t len)
 {
 	if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) {
@@ -64,7 +66,7 @@ static __always_inline ssize_t
 __cvdso_getrandom_data(const struct vdso_rng_data *rng_info, void *buffer, size_t len,
 		       unsigned int flags, void *opaque_state, size_t opaque_len)
 {
-	ssize_t ret = min_t(size_t, INT_MAX & PAGE_MASK /* = MAX_RW_COUNT */, len);
+	ssize_t ret = min_t(size_t, INT_MAX & _PAGE_MASK /* = MAX_RW_COUNT */, len);
 	struct vgetrandom_state *state = opaque_state;
 	size_t batch_len, nblocks, orig_len = len;
 	bool in_use, have_retried = false;
@@ -73,16 +75,20 @@ __cvdso_getrandom_data(const struct vdso_rng_data *rng_info, void *buffer, size_
 	u32 counter[2] = { 0 };
 
 	if (unlikely(opaque_len == ~0UL && !buffer && !len && !flags)) {
-		*(struct vgetrandom_opaque_params *)opaque_state = (struct vgetrandom_opaque_params) {
-			.size_of_opaque_state = sizeof(*state),
-			.mmap_prot = PROT_READ | PROT_WRITE,
-			.mmap_flags = MAP_DROPPABLE | MAP_ANONYMOUS
-		};
+		struct vgetrandom_opaque_params *params = opaque_state;
+		int i;
+
+		params->size_of_opaque_state = sizeof(*state);
+		params->mmap_prot = PROT_READ | PROT_WRITE;
+		params->mmap_flags = MAP_DROPPABLE | MAP_ANONYMOUS;
+		for (i = 0; i < ARRAY_SIZE(params->reserved); i++)
+			params->reserved[i] = 0;
+
 		return 0;
 	}
 
 	/* The state must not straddle a page, since pages can be zeroed at any time. */
-	if (unlikely(((unsigned long)opaque_state & ~PAGE_MASK) + sizeof(*state) > PAGE_SIZE))
+	if (unlikely(((unsigned long)opaque_state & ~_PAGE_MASK) + sizeof(*state) > _PAGE_SIZE))
 		return -EFAULT;
 
 	/* If the caller passes the wrong size, which might happen due to CRIU, fallback. */
diff --git a/tools/arch/powerpc/vdso b/tools/arch/powerpc/vdso
new file mode 120000
index 0000000000000..d31004bf8f555
--- /dev/null
+++ b/tools/arch/powerpc/vdso
@@ -0,0 +1 @@
+../../../arch/powerpc/kernel/vdso/
\ No newline at end of file
diff --git a/tools/arch/x86/vdso b/tools/arch/x86/vdso
new file mode 120000
index 0000000000000..7eb962fd3454c
--- /dev/null
+++ b/tools/arch/x86/vdso
@@ -0,0 +1 @@
+../../../arch/x86/entry/vdso/
\ No newline at end of file
diff --git a/tools/include/linux/linkage.h b/tools/include/linux/linkage.h
index bc763d5002626..a48ff086899cd 100644
--- a/tools/include/linux/linkage.h
+++ b/tools/include/linux/linkage.h
@@ -1,4 +1,8 @@
 #ifndef _TOOLS_INCLUDE_LINUX_LINKAGE_H
 #define _TOOLS_INCLUDE_LINUX_LINKAGE_H
 
+#define SYM_FUNC_START(x) .globl x; x:
+
+#define SYM_FUNC_END(x)
+
 #endif /* _TOOLS_INCLUDE_LINUX_LINKAGE_H */
diff --git a/tools/testing/selftests/vDSO/Makefile b/tools/testing/selftests/vDSO/Makefile
index 3de8e7e052ae2..7e7c9fd200d3c 100644
--- a/tools/testing/selftests/vDSO/Makefile
+++ b/tools/testing/selftests/vDSO/Makefile
@@ -17,6 +17,12 @@ ifneq ($(SODIUM),)
 TEST_GEN_PROGS += vdso_test_chacha
 endif
 endif
+ifeq ($(ARCH),powerpc)
+TEST_GEN_PROGS += vdso_test_getrandom
+ifneq ($(SODIUM),)
+TEST_GEN_PROGS += vdso_test_chacha
+endif
+endif
 
 CFLAGS := -std=gnu99
 
@@ -40,9 +46,9 @@ $(OUTPUT)/vdso_test_getrandom: parse_vdso.c
 $(OUTPUT)/vdso_test_getrandom: CFLAGS += -isystem $(top_srcdir)/tools/include \
                                          -isystem $(top_srcdir)/include/uapi
 
-$(OUTPUT)/vdso_test_chacha: $(top_srcdir)/arch/$(ARCH)/entry/vdso/vgetrandom-chacha.S
+$(OUTPUT)/vdso_test_chacha: $(top_srcdir)/tools/arch/$(ARCH)/vdso/vgetrandom-chacha.S
 $(OUTPUT)/vdso_test_chacha: CFLAGS += -idirafter $(top_srcdir)/tools/include \
-                                      -isystem $(top_srcdir)/arch/$(ARCH)/include \
-                                      -isystem $(top_srcdir)/include \
+                                      -idirafter $(top_srcdir)/arch/$(ARCH)/include \
+                                      -idirafter $(top_srcdir)/include \
                                       -D__ASSEMBLY__ -DBULID_VDSO -DCONFIG_FUNCTION_ALIGNMENT=0 \
                                       -Wa,--noexecstack $(SODIUM)
diff --git a/tools/testing/selftests/vDSO/vdso_call.h b/tools/testing/selftests/vDSO/vdso_call.h
new file mode 100644
index 0000000000000..2a33c25756dc5
--- /dev/null
+++ b/tools/testing/selftests/vDSO/vdso_call.h
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Macro to call vDSO functions
+ *
+ * Copyright (C) 2024 Christophe Leroy <christophe.leroy@csgroup.eu>, CS GROUP France
+ */
+#ifndef __VDSO_CALL_H__
+#define __VDSO_CALL_H__
+
+#ifdef __powerpc__
+
+#define LOADARGS_5(fn, __arg1, __arg2, __arg3, __arg4, __arg5) do { 	\
+	_r0 = fn;							\
+	_r3 = (long)__arg1;						\
+	_r4 = (long)__arg2;						\
+	_r5 = (long)__arg3;						\
+	_r6 = (long)__arg4;						\
+	_r7 = (long)__arg5;						\
+} while (0)
+
+#define VDSO_CALL(fn, nr, args...) ({					\
+	register void *_r0 asm ("r0");					\
+	register long _r3 asm ("r3");					\
+	register long _r4 asm ("r4");					\
+	register long _r5 asm ("r5");					\
+	register long _r6 asm ("r6");					\
+	register long _r7 asm ("r7");					\
+	register long _r8 asm ("r8");					\
+	register long _rval asm ("r3");					\
+									\
+	LOADARGS_##nr(fn, args);					\
+									\
+	asm volatile(							\
+		"	mtctr %0\n"					\
+		"	bctrl\n"					\
+		"	bns+	1f\n"					\
+		"	neg	3, 3\n"					\
+		"1:"							\
+		: "+r" (_r0), "=r" (_r3), "+r" (_r4), "+r" (_r5),	\
+		  "+r" (_r6), "+r" (_r7), "+r" (_r8)			\
+		: "r" (_rval)						\
+		: "r9", "r10", "r11", "r12", "cr0", "cr1", "cr5",	\
+		  "cr6", "cr7", "xer", "lr", "ctr", "memory"		\
+	);								\
+	_rval;								\
+})
+
+#else
+#define VDSO_CALL(fn, nr, args...)	fn(args)
+#endif
+
+#endif
diff --git a/tools/testing/selftests/vDSO/vdso_config.h b/tools/testing/selftests/vDSO/vdso_config.h
index 7b543e7f04d7b..740ce8c98d2e7 100644
--- a/tools/testing/selftests/vDSO/vdso_config.h
+++ b/tools/testing/selftests/vDSO/vdso_config.h
@@ -18,13 +18,13 @@
 #elif defined(__aarch64__)
 #define VDSO_VERSION		3
 #define VDSO_NAMES		0
-#elif defined(__powerpc__)
+#elif defined(__powerpc64__)
 #define VDSO_VERSION		1
 #define VDSO_NAMES		0
-#define VDSO_32BIT		1
-#elif defined(__powerpc64__)
+#elif defined(__powerpc__)
 #define VDSO_VERSION		1
 #define VDSO_NAMES		0
+#define VDSO_32BIT		1
 #elif defined (__s390__)
 #define VDSO_VERSION		2
 #define VDSO_NAMES		0
@@ -68,16 +68,15 @@ static const char *versions[7] = {
 	"LINUX_5.10"
 };
 
-static const char *names[2][6] = {
+static const char *names[2][7] = {
 	{
 		"__kernel_gettimeofday",
 		"__kernel_clock_gettime",
 		"__kernel_time",
 		"__kernel_clock_getres",
 		"__kernel_getcpu",
-#if defined(VDSO_32BIT)
 		"__kernel_clock_gettime64",
-#endif
+		"__kernel_getrandom",
 	},
 	{
 		"__vdso_gettimeofday",
@@ -85,9 +84,8 @@ static const char *names[2][6] = {
 		"__vdso_time",
 		"__vdso_clock_getres",
 		"__vdso_getcpu",
-#if defined(VDSO_32BIT)
 		"__vdso_clock_gettime64",
-#endif
+		"__vdso_getrandom",
 	},
 };
 
diff --git a/tools/testing/selftests/vDSO/vdso_test_getrandom.c b/tools/testing/selftests/vDSO/vdso_test_getrandom.c
index 05122425a873f..16ad400721c39 100644
--- a/tools/testing/selftests/vDSO/vdso_test_getrandom.c
+++ b/tools/testing/selftests/vDSO/vdso_test_getrandom.c
@@ -21,6 +21,8 @@
 
 #include "../kselftest.h"
 #include "parse_vdso.h"
+#include "vdso_config.h"
+#include "vdso_call.h"
 
 #ifndef timespecsub
 #define	timespecsub(tsp, usp, vsp)					\
@@ -107,6 +109,9 @@ static void vgetrandom_put_state(void *state)
 
 static void vgetrandom_init(void)
 {
+	const char *version = versions[VDSO_VERSION];
+	const char **name = (const char **)&names[VDSO_NAMES];
+
 	if (pthread_key_create(&grnd_ctx.key, vgetrandom_put_state) != 0)
 		return;
 	unsigned long sysinfo_ehdr = getauxval(AT_SYSINFO_EHDR);
@@ -115,9 +120,9 @@ static void vgetrandom_init(void)
 		exit(KSFT_SKIP);
 	}
 	vdso_init_from_sysinfo_ehdr(sysinfo_ehdr);
-	grnd_ctx.fn = (__typeof__(grnd_ctx.fn))vdso_sym("LINUX_2.6", "__vdso_getrandom");
+	grnd_ctx.fn = (__typeof__(grnd_ctx.fn))vdso_sym(version, name[6]);
 	if (!grnd_ctx.fn) {
-		printf("__vdso_getrandom is missing!\n");
+		printf("%s is missing!\n", name[6]);
 		exit(KSFT_FAIL);
 	}
 	if (grnd_ctx.fn(NULL, 0, 0, &grnd_ctx.params, ~0UL) != 0) {
@@ -143,7 +148,7 @@ static ssize_t vgetrandom(void *buf, size_t len, unsigned long flags)
 			exit(KSFT_FAIL);
 		}
 	}
-	return grnd_ctx.fn(buf, len, flags, state, grnd_ctx.params.size_of_opaque_state);
+	return VDSO_CALL(grnd_ctx.fn, 5, buf, len, flags, state, grnd_ctx.params.size_of_opaque_state);
 }
 
 enum { TRIALS = 25000000, THREADS = 256 };