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Fox Snowpatch
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From patchwork series 419688
https://patchwork.ozlabs.org//project/linuxppc-dev/list/?series=419688
1 parent ddf9a4c commit d65b372

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21 files changed

+553
-47
lines changed

21 files changed

+553
-47
lines changed

‎arch/powerpc/Kconfig

+1
Original file line numberDiff line numberDiff line change
@@ -311,6 +311,7 @@ config PPC
311311
select SYSCTL_EXCEPTION_TRACE
312312
select THREAD_INFO_IN_TASK
313313
select TRACE_IRQFLAGS_SUPPORT
314+
select VDSO_GETRANDOM if !COMPAT
314315
#
315316
# Please keep this list sorted alphabetically.
316317
#

‎arch/powerpc/include/asm/asm-compat.h

+26-14
Original file line numberDiff line numberDiff line change
@@ -25,20 +25,6 @@
2525
#define PPC_LR_STKOFF 16
2626
#define PPC_MIN_STKFRM 112
2727

28-
#ifdef __BIG_ENDIAN__
29-
#define LHZX_BE stringify_in_c(lhzx)
30-
#define LWZX_BE stringify_in_c(lwzx)
31-
#define LDX_BE stringify_in_c(ldx)
32-
#define STWX_BE stringify_in_c(stwx)
33-
#define STDX_BE stringify_in_c(stdx)
34-
#else
35-
#define LHZX_BE stringify_in_c(lhbrx)
36-
#define LWZX_BE stringify_in_c(lwbrx)
37-
#define LDX_BE stringify_in_c(ldbrx)
38-
#define STWX_BE stringify_in_c(stwbrx)
39-
#define STDX_BE stringify_in_c(stdbrx)
40-
#endif
41-
4228
#else /* 32-bit */
4329

4430
/* operations for longs and pointers */
@@ -61,4 +47,30 @@
6147

6248
#endif
6349

50+
#ifdef __BIG_ENDIAN__
51+
#define LHZX_BE stringify_in_c(lhzx)
52+
#define LWZX_BE stringify_in_c(lwzx)
53+
#define LDX_BE stringify_in_c(ldx)
54+
#define STWX_BE stringify_in_c(stwx)
55+
#define STDX_BE stringify_in_c(stdx)
56+
57+
#define LHZX_LE stringify_in_c(lhbrx)
58+
#define LWZX_LE stringify_in_c(lwbrx)
59+
#define LDX_LE stringify_in_c(ldbrx)
60+
#define STWX_LE stringify_in_c(stwbrx)
61+
#define STDX_LE stringify_in_c(stdbrx)
62+
#else
63+
#define LHZX_BE stringify_in_c(lhbrx)
64+
#define LWZX_BE stringify_in_c(lwbrx)
65+
#define LDX_BE stringify_in_c(ldbrx)
66+
#define STWX_BE stringify_in_c(stwbrx)
67+
#define STDX_BE stringify_in_c(stdbrx)
68+
69+
#define LHZX_LE stringify_in_c(lhzx)
70+
#define LWZX_LE stringify_in_c(lwzx)
71+
#define LDX_LE stringify_in_c(ldx)
72+
#define STWX_LE stringify_in_c(stwx)
73+
#define STDX_LE stringify_in_c(stdx)
74+
#endif
75+
6476
#endif /* _ASM_POWERPC_ASM_COMPAT_H */

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

+61
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,61 @@
1+
/* SPDX-License-Identifier: GPL-2.0 */
2+
#ifndef _ASM_POWERPC_VDSO_GETRANDOM_H
3+
#define _ASM_POWERPC_VDSO_GETRANDOM_H
4+
5+
#ifndef __ASSEMBLY__
6+
7+
static __always_inline int do_syscall_3(const unsigned long _r0, const unsigned long _r3,
8+
const unsigned long _r4, const unsigned long _r5)
9+
{
10+
register long r0 asm("r0") = _r0;
11+
register unsigned long r3 asm("r3") = _r3;
12+
register unsigned long r4 asm("r4") = _r4;
13+
register unsigned long r5 asm("r5") = _r5;
14+
register int ret asm ("r3");
15+
16+
asm volatile(
17+
" sc\n"
18+
" bns+ 1f\n"
19+
" neg %0, %0\n"
20+
"1:\n"
21+
: "=r" (ret), "+r" (r4), "+r" (r5), "+r" (r0)
22+
: "r" (r3)
23+
: "memory", "r6", "r7", "r8", "r9", "r10", "r11", "r12", "cr0", "ctr");
24+
25+
return ret;
26+
}
27+
28+
/**
29+
* getrandom_syscall - Invoke the getrandom() syscall.
30+
* @buffer: Destination buffer to fill with random bytes.
31+
* @len: Size of @buffer in bytes.
32+
* @flags: Zero or more GRND_* flags.
33+
* Returns: The number of random bytes written to @buffer, or a negative value indicating an error.
34+
*/
35+
static __always_inline ssize_t getrandom_syscall(void *buffer, size_t len, unsigned int flags)
36+
{
37+
return do_syscall_3(__NR_getrandom, (unsigned long)buffer,
38+
(unsigned long)len, (unsigned long)flags);
39+
}
40+
41+
const struct vdso_rng_data *__arch_get_vdso_rng_data(void);
42+
43+
ssize_t __c_kernel_getrandom(void *buffer, size_t len, unsigned int flags, void *opaque_state,
44+
size_t opaque_len, const struct vdso_rng_data *vd);
45+
46+
/**
47+
* __arch_chacha20_blocks_nostack - Generate ChaCha20 stream without using the stack.
48+
* @dst_bytes: Destination buffer to hold @nblocks * 64 bytes of output.
49+
* @key: 32-byte input key.
50+
* @counter: 8-byte counter, read on input and updated on return.
51+
* @nblocks: Number of blocks to generate.
52+
*
53+
* Generates a given positive number of blocks of ChaCha20 output with nonce=0, and does not write
54+
* to any stack or memory outside of the parameters passed to it, in order to mitigate stack data
55+
* leaking into forked child processes.
56+
*/
57+
void __arch_chacha20_blocks_nostack(u8 *dst_bytes, const u32 *key, u32 *counter, size_t nblocks);
58+
59+
#endif /* !__ASSEMBLY__ */
60+
61+
#endif /* _ASM_POWERPC_VDSO_GETRANDOM_H */

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

+7
Original file line numberDiff line numberDiff line change
@@ -17,6 +17,13 @@ struct vdso_data *__arch_get_k_vdso_data(void)
1717
}
1818
#define __arch_get_k_vdso_data __arch_get_k_vdso_data
1919

20+
static __always_inline
21+
struct vdso_rng_data *__arch_get_k_vdso_rng_data(void)
22+
{
23+
return &vdso_data->rng_data;
24+
}
25+
#define __arch_get_k_vdso_rng_data __arch_get_k_vdso_rng_data
26+
2027
/* The asm-generic header needs to be included after the definitions above */
2128
#include <asm-generic/vdso/vsyscall.h>
2229

‎arch/powerpc/include/asm/vdso_datapage.h

+2
Original file line numberDiff line numberDiff line change
@@ -83,6 +83,7 @@ struct vdso_arch_data {
8383
__u32 compat_syscall_map[SYSCALL_MAP_SIZE]; /* Map of compat syscalls */
8484

8585
struct vdso_data data[CS_BASES];
86+
struct vdso_rng_data rng_data;
8687
};
8788

8889
#else /* CONFIG_PPC64 */
@@ -95,6 +96,7 @@ struct vdso_arch_data {
9596
__u32 syscall_map[SYSCALL_MAP_SIZE]; /* Map of syscalls */
9697
__u32 compat_syscall_map[0]; /* No compat syscalls on PPC32 */
9798
struct vdso_data data[CS_BASES];
99+
struct vdso_rng_data rng_data;
98100
};
99101

100102
#endif /* CONFIG_PPC64 */

‎arch/powerpc/kernel/asm-offsets.c

+1
Original file line numberDiff line numberDiff line change
@@ -335,6 +335,7 @@ int main(void)
335335

336336
/* datapage offsets for use by vdso */
337337
OFFSET(VDSO_DATA_OFFSET, vdso_arch_data, data);
338+
OFFSET(VDSO_RNG_DATA_OFFSET, vdso_arch_data, rng_data);
338339
OFFSET(CFG_TB_TICKS_PER_SEC, vdso_arch_data, tb_ticks_per_sec);
339340
#ifdef CONFIG_PPC64
340341
OFFSET(CFG_ICACHE_BLOCKSZ, vdso_arch_data, icache_block_size);

‎arch/powerpc/kernel/vdso/Makefile

+40-4
Original file line numberDiff line numberDiff line change
@@ -8,6 +8,9 @@ include $(srctree)/lib/vdso/Makefile
88
obj-vdso32 = sigtramp32-32.o gettimeofday-32.o datapage-32.o cacheflush-32.o note-32.o getcpu-32.o
99
obj-vdso64 = sigtramp64-64.o gettimeofday-64.o datapage-64.o cacheflush-64.o note-64.o getcpu-64.o
1010

11+
obj-vdso32 += getrandom-32.o vgetrandom-chacha-32.o
12+
obj-vdso64 += getrandom-64.o vgetrandom-chacha-64.o
13+
1114
ifneq ($(c-gettimeofday-y),)
1215
CFLAGS_vgettimeofday-32.o += -include $(c-gettimeofday-y)
1316
CFLAGS_vgettimeofday-32.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)
@@ -34,6 +37,32 @@ ifneq ($(c-gettimeofday-y),)
3437
CFLAGS_vgettimeofday-64.o += $(call cc-option, -ffixed-r30)
3538
endif
3639

40+
ifneq ($(c-getrandom-y),)
41+
CFLAGS_vgetrandom-32.o += -include $(c-getrandom-y)
42+
CFLAGS_vgetrandom-32.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)
43+
CFLAGS_vgetrandom-32.o += $(call cc-option, -fno-stack-protector)
44+
CFLAGS_vgetrandom-32.o += -DDISABLE_BRANCH_PROFILING
45+
CFLAGS_vgetrandom-32.o += -ffreestanding -fasynchronous-unwind-tables
46+
CFLAGS_REMOVE_vgetrandom-32.o = $(CC_FLAGS_FTRACE)
47+
CFLAGS_REMOVE_vgetrandom-32.o += -mcmodel=medium -mabi=elfv1 -mabi=elfv2 -mcall-aixdesc
48+
# This flag is supported by clang for 64-bit but not 32-bit so it will cause
49+
# an unused command line flag warning for this file.
50+
ifdef CONFIG_CC_IS_CLANG
51+
CFLAGS_REMOVE_vgetrandom-32.o += -fno-stack-clash-protection
52+
endif
53+
CFLAGS_vgetrandom-64.o += -include $(c-getrandom-y)
54+
CFLAGS_vgetrandom-64.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)
55+
CFLAGS_vgetrandom-64.o += $(call cc-option, -fno-stack-protector)
56+
CFLAGS_vgetrandom-64.o += -DDISABLE_BRANCH_PROFILING
57+
CFLAGS_vgetrandom-64.o += -ffreestanding -fasynchronous-unwind-tables
58+
CFLAGS_REMOVE_vgetrandom-64.o = $(CC_FLAGS_FTRACE)
59+
# Go prior to 1.16.x assumes r30 is not clobbered by any VDSO code. That used to be true
60+
# by accident when the VDSO was hand-written asm code, but may not be now that the VDSO is
61+
# compiler generated. To avoid breaking Go tell GCC not to use r30. Impact on code
62+
# generation is minimal, it will just use r29 instead.
63+
CFLAGS_vgetrandom-64.o += $(call cc-option, -ffixed-r30)
64+
endif
65+
3766
# Build rules
3867

3968
ifdef CROSS32_COMPILE
@@ -42,9 +71,10 @@ else
4271
VDSOCC := $(CC)
4372
endif
4473

45-
targets := $(obj-vdso32) vdso32.so.dbg vgettimeofday-32.o
74+
targets := $(obj-vdso32) vdso32.so.dbg vgettimeofday-32.o vgetrandom-32.o
75+
targets += crtsavres-32.o
4676
obj-vdso32 := $(addprefix $(obj)/, $(obj-vdso32))
47-
targets += $(obj-vdso64) vdso64.so.dbg vgettimeofday-64.o
77+
targets += $(obj-vdso64) vdso64.so.dbg vgettimeofday-64.o vgetrandom-64.o
4878
obj-vdso64 := $(addprefix $(obj)/, $(obj-vdso64))
4979

5080
ccflags-y := -fno-common -fno-builtin
@@ -68,20 +98,26 @@ targets += vdso64.lds
6898
CPPFLAGS_vdso64.lds += -P -C
6999

70100
# link rule for the .so file, .lds has to be first
71-
$(obj)/vdso32.so.dbg: $(obj)/vdso32.lds $(obj-vdso32) $(obj)/vgettimeofday-32.o FORCE
101+
$(obj)/vdso32.so.dbg: $(obj)/vdso32.lds $(obj-vdso32) $(obj)/vgettimeofday-32.o $(obj)/vgetrandom-32.o $(obj)/crtsavres-32.o FORCE
72102
$(call if_changed,vdso32ld_and_check)
73-
$(obj)/vdso64.so.dbg: $(obj)/vdso64.lds $(obj-vdso64) $(obj)/vgettimeofday-64.o FORCE
103+
$(obj)/vdso64.so.dbg: $(obj)/vdso64.lds $(obj-vdso64) $(obj)/vgettimeofday-64.o $(obj)/vgetrandom-64.o FORCE
74104
$(call if_changed,vdso64ld_and_check)
75105

76106
# assembly rules for the .S files
77107
$(obj-vdso32): %-32.o: %.S FORCE
78108
$(call if_changed_dep,vdso32as)
109+
$(obj)/crtsavres-32.o: %-32.o: $(srctree)/arch/powerpc/lib/crtsavres.S FORCE
110+
$(call if_changed_dep,vdso32as)
79111
$(obj)/vgettimeofday-32.o: %-32.o: %.c FORCE
80112
$(call if_changed_dep,vdso32cc)
113+
$(obj)/vgetrandom-32.o: %-32.o: %.c FORCE
114+
$(call if_changed_dep,vdso32cc)
81115
$(obj-vdso64): %-64.o: %.S FORCE
82116
$(call if_changed_dep,vdso64as)
83117
$(obj)/vgettimeofday-64.o: %-64.o: %.c FORCE
84118
$(call if_changed_dep,cc_o_c)
119+
$(obj)/vgetrandom-64.o: %-64.o: %.c FORCE
120+
$(call if_changed_dep,cc_o_c)
85121

86122
# Generate VDSO offsets using helper script
87123
gen-vdso32sym := $(src)/gen_vdso32_offsets.sh

‎arch/powerpc/kernel/vdso/getrandom.S

+62
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,62 @@
1+
/* SPDX-License-Identifier: GPL-2.0-or-later */
2+
/*
3+
* Userland implementation of getrandom() for processes
4+
* for use in the vDSO
5+
*
6+
* Copyright (C) 2024 Christophe Leroy <[email protected]>, CS GROUP France
7+
*/
8+
#include <asm/processor.h>
9+
#include <asm/ppc_asm.h>
10+
#include <asm/vdso.h>
11+
#include <asm/vdso_datapage.h>
12+
#include <asm/asm-offsets.h>
13+
#include <asm/unistd.h>
14+
15+
/*
16+
* The macro sets two stack frames, one for the caller and one for the callee
17+
* because there are no requirement for the caller to set a stack frame when
18+
* calling VDSO so it may have omitted to set one, especially on PPC64
19+
*/
20+
21+
.macro cvdso_call funct
22+
.cfi_startproc
23+
PPC_STLU r1, -PPC_MIN_STKFRM(r1)
24+
.cfi_adjust_cfa_offset PPC_MIN_STKFRM
25+
mflr r0
26+
PPC_STLU r1, -PPC_MIN_STKFRM(r1)
27+
.cfi_adjust_cfa_offset PPC_MIN_STKFRM
28+
PPC_STL r0, PPC_MIN_STKFRM + PPC_LR_STKOFF(r1)
29+
.cfi_rel_offset lr, PPC_MIN_STKFRM + PPC_LR_STKOFF
30+
#ifdef __powerpc64__
31+
PPC_STL r2, PPC_MIN_STKFRM + STK_GOT(r1)
32+
.cfi_rel_offset r2, PPC_MIN_STKFRM + STK_GOT
33+
#endif
34+
get_datapage r8
35+
addi r8, r8, VDSO_RNG_DATA_OFFSET
36+
#ifdef __powerpc64__
37+
bl CFUNC(DOTSYM(\funct))
38+
#else
39+
bl \funct
40+
#endif
41+
PPC_LL r0, PPC_MIN_STKFRM + PPC_LR_STKOFF(r1)
42+
#ifdef __powerpc64__
43+
PPC_LL r2, PPC_MIN_STKFRM + STK_GOT(r1)
44+
.cfi_restore r2
45+
#endif
46+
cmpwi r3, 0
47+
mtlr r0
48+
addi r1, r1, 2 * PPC_MIN_STKFRM
49+
.cfi_restore lr
50+
.cfi_def_cfa_offset 0
51+
crclr so
52+
bgelr+
53+
crset so
54+
neg r3, r3
55+
blr
56+
.cfi_endproc
57+
.endm
58+
59+
.text
60+
V_FUNCTION_BEGIN(__kernel_getrandom)
61+
cvdso_call __c_kernel_getrandom
62+
V_FUNCTION_END(__kernel_getrandom)

‎arch/powerpc/kernel/vdso/gettimeofday.S

-13
Original file line numberDiff line numberDiff line change
@@ -118,16 +118,3 @@ V_FUNCTION_END(__kernel_clock_getres)
118118
V_FUNCTION_BEGIN(__kernel_time)
119119
cvdso_call __c_kernel_time call_time=1
120120
V_FUNCTION_END(__kernel_time)
121-
122-
/* Routines for restoring integer registers, called by the compiler. */
123-
/* Called with r11 pointing to the stack header word of the caller of the */
124-
/* function, just beyond the end of the integer restore area. */
125-
#ifndef __powerpc64__
126-
_GLOBAL(_restgpr_31_x)
127-
_GLOBAL(_rest32gpr_31_x)
128-
lwz r0,4(r11)
129-
lwz r31,-4(r11)
130-
mtlr r0
131-
mr r1,r11
132-
blr
133-
#endif

‎arch/powerpc/kernel/vdso/vdso32.lds.S

+4-1
Original file line numberDiff line numberDiff line change
@@ -74,6 +74,8 @@ SECTIONS
7474
.got : { *(.got) } :text
7575
.plt : { *(.plt) }
7676

77+
.rela.dyn : { *(.rela .rela*) }
78+
7779
_end = .;
7880
__end = .;
7981
PROVIDE(end = .);
@@ -87,7 +89,7 @@ SECTIONS
8789
*(.branch_lt)
8890
*(.data .data.* .gnu.linkonce.d.* .sdata*)
8991
*(.bss .sbss .dynbss .dynsbss)
90-
*(.got1 .glink .iplt .rela*)
92+
*(.got1 .glink .iplt)
9193
}
9294
}
9395

@@ -128,6 +130,7 @@ VERSION
128130
#if defined(CONFIG_PPC64) || !defined(CONFIG_SMP)
129131
__kernel_getcpu;
130132
#endif
133+
__kernel_getrandom;
131134

132135
local: *;
133136
};

‎arch/powerpc/kernel/vdso/vdso64.lds.S

+3-2
Original file line numberDiff line numberDiff line change
@@ -69,7 +69,7 @@ SECTIONS
6969
.eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr
7070
.eh_frame : { KEEP (*(.eh_frame)) } :text
7171
.gcc_except_table : { *(.gcc_except_table) }
72-
.rela.dyn ALIGN(8) : { *(.rela.dyn) }
72+
.rela.dyn ALIGN(8) : { *(.rela .rela*) }
7373

7474
.got ALIGN(8) : { *(.got .toc) }
7575

@@ -86,7 +86,7 @@ SECTIONS
8686
*(.data .data.* .gnu.linkonce.d.* .sdata*)
8787
*(.bss .sbss .dynbss .dynsbss)
8888
*(.opd)
89-
*(.glink .iplt .plt .rela*)
89+
*(.glink .iplt .plt)
9090
}
9191
}
9292

@@ -123,6 +123,7 @@ VERSION
123123
__kernel_sigtramp_rt64;
124124
__kernel_getcpu;
125125
__kernel_time;
126+
__kernel_getrandom;
126127

127128
local: *;
128129
};

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