Re: [PATCH 9/9] vdso: Modify getrandom to include the correct namespace

Christophe Leroy
2024-09-06T12:04:42Z

Le 06/09/2024 à 13:52, Vincenzo Frascino a écrit :
>
>
> On 04/09/2024 18:26, Christophe Leroy wrote:
>>
>>
>> Le 03/09/2024 à 17:14, Vincenzo Frascino a écrit :
> ...
>
>>
>> Now build fails on powerpc because struct vgetrandom_opaque_params is unknown.
>>
>> x86 get it by chance via the following header inclusion chain:
>>
>> In file included from ./include/linux/random.h:10,
>>                  from ./include/linux/nodemask.h:98,
>>                  from ./include/linux/mmzone.h:18,
>>                  from ./include/linux/gfp.h:7,
>>                  from ./include/linux/xarray.h:16,
>>                  from ./include/linux/radix-tree.h:21,
>>                  from ./include/linux/idr.h:15,
>>                  from ./include/linux/kernfs.h:12,
>>                  from ./include/linux/sysfs.h:16,
>>                  from ./include/linux/kobject.h:20,
>>                  from ./include/linux/of.h:18,
>>                  from ./include/linux/clocksource.h:19,
>>                  from ./include/clocksource/hyperv_timer.h:16,
>>                  from ./arch/x86/include/asm/vdso/gettimeofday.h:21,
>>                  from ./include/vdso/datapage.h:164,
>>                  from arch/x86/entry/vdso/../../../../lib/vdso/getrandom.c:7,
>>                  from arch/x86/entry/vdso/vgetrandom.c:7:
>>
>>
>>
>>
>
> This tells me very little ;)
>
> Can you please provide more details? e.g. What is the error you are getting? How
> do I reproduce it?
>
> I am happy to include the required change as part of this series.
>
> Overall, the reason why I am doing this exercise it to sanitize the headers for
> all the architectures so that in future we do not have issues. It is good we
> find problems now.
>

More details:

$ make ARCH=powerpc CROSS_COMPILE=ppc-linux- mpc885_ads_defconfig

$ LANG= make ARCH=powerpc CROSS_COMPILE=ppc-linux- vmlinux
SYNC include/config/auto.conf
SYSHDR arch/powerpc/include/generated/uapi/asm/unistd_32.h
SYSHDR arch/powerpc/include/generated/uapi/asm/unistd_64.h
SYSTBL arch/powerpc/include/generated/asm/syscall_table_32.h
SYSTBL arch/powerpc/include/generated/asm/syscall_table_64.h
SYSTBL arch/powerpc/include/generated/asm/syscall_table_spu.h
HOSTCC scripts/dtc/dtc.o
HOSTCC scripts/dtc/flattree.o
HOSTCC scripts/dtc/fstree.o
HOSTCC scripts/dtc/data.o
HOSTCC scripts/dtc/livetree.o
HOSTCC scripts/dtc/treesource.o
HOSTCC scripts/dtc/srcpos.o
HOSTCC scripts/dtc/checks.o
HOSTCC scripts/dtc/util.o
LEX scripts/dtc/dtc-lexer.lex.c
YACC scripts/dtc/dtc-parser.tab.[ch]
HOSTCC scripts/dtc/dtc-lexer.lex.o
HOSTCC scripts/dtc/dtc-parser.tab.o
HOSTLD scripts/dtc/dtc
HOSTCC scripts/dtc/libfdt/fdt.o
HOSTCC scripts/dtc/libfdt/fdt_ro.o
HOSTCC scripts/dtc/libfdt/fdt_wip.o
HOSTCC scripts/dtc/libfdt/fdt_sw.o
HOSTCC scripts/dtc/libfdt/fdt_rw.o
HOSTCC scripts/dtc/libfdt/fdt_strerror.o
HOSTCC scripts/dtc/libfdt/fdt_empty_tree.o
HOSTCC scripts/dtc/libfdt/fdt_addresses.o
HOSTCC scripts/dtc/libfdt/fdt_overlay.o
HOSTCC scripts/dtc/fdtoverlay.o
HOSTLD scripts/dtc/fdtoverlay
HOSTCC scripts/kallsyms
HOSTCC scripts/sorttable
CC scripts/mod/empty.o
HOSTCC scripts/mod/mk_elfconfig
MKELF scripts/mod/elfconfig.h
HOSTCC scripts/mod/modpost.o
CC scripts/mod/devicetable-offsets.s
HOSTCC scripts/mod/file2alias.o
HOSTCC scripts/mod/sumversion.o
HOSTCC scripts/mod/symsearch.o
HOSTLD scripts/mod/modpost
CC kernel/bounds.s
CC arch/powerpc/kernel/asm-offsets.s
CALL scripts/checksyscalls.sh
CHKSHA1 include/linux/atomic/atomic-arch-fallback.h
CHKSHA1 include/linux/atomic/atomic-instrumented.h
CHKSHA1 include/linux/atomic/atomic-long.h
LDS arch/powerpc/kernel/vdso/vdso32.lds
VDSO32A arch/powerpc/kernel/vdso/sigtramp32-32.o
VDSO32A arch/powerpc/kernel/vdso/gettimeofday-32.o
VDSO32A arch/powerpc/kernel/vdso/datapage-32.o
VDSO32A arch/powerpc/kernel/vdso/cacheflush-32.o
VDSO32A arch/powerpc/kernel/vdso/note-32.o
VDSO32A arch/powerpc/kernel/vdso/getcpu-32.o
VDSO32A arch/powerpc/kernel/vdso/getrandom-32.o
VDSO32A arch/powerpc/kernel/vdso/vgetrandom-chacha-32.o
VDSO32C arch/powerpc/kernel/vdso/vgettimeofday-32.o
VDSO32C arch/powerpc/kernel/vdso/vgetrandom-32.o
In file included from <command-line>:
/home/chleroy/linux-powerpc/lib/vdso/getrandom.c: In function
'__cvdso_getrandom_data':
/home/chleroy/linux-powerpc/lib/vdso/getrandom.c:75:23: error: invalid
use of undefined type 'struct vgetrandom_opaque_params'
75 | params->size_of_opaque_state = sizeof(*state);
| ^~
/home/chleroy/linux-powerpc/lib/vdso/getrandom.c:76:23: error: invalid
use of undefined type 'struct vgetrandom_opaque_params'
76 | params->mmap_prot = VDSO_MMAP_PROT;
| ^~
/home/chleroy/linux-powerpc/lib/vdso/getrandom.c:77:23: error: invalid
use of undefined type 'struct vgetrandom_opaque_params'
77 | params->mmap_flags = VDSO_MMAP_FLAGS;
| ^~
In file included from ./include/linux/array_size.h:5,
from ./include/linux/kernel.h:16,
from ./arch/powerpc/include/asm/page.h:11,
from ./arch/powerpc/include/asm/vdso/page.h:8,
from ./include/vdso/page.h:5,
from /home/chleroy/linux-powerpc/lib/vdso/getrandom.c:10:
/home/chleroy/linux-powerpc/lib/vdso/getrandom.c:78:57: error: invalid
use of undefined type 'struct vgetrandom_opaque_params'
78 | for (size_t i = 0; i <
ARRAY_SIZE(params->reserved); ++i)
| ^~
./include/vdso/array_size.h:11:33: note: in definition of macro 'ARRAY_SIZE'
11 | #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) +
__must_be_array(arr))
| ^~~
/home/chleroy/linux-powerpc/lib/vdso/getrandom.c:78:57: error: invalid
use of undefined type 'struct vgetrandom_opaque_params'
78 | for (size_t i = 0; i <
ARRAY_SIZE(params->reserved); ++i)
| ^~
./include/vdso/array_size.h:11:48: note: in definition of macro 'ARRAY_SIZE'
11 | #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) +
__must_be_array(arr))
| ^~~
In file included from ./include/linux/container_of.h:5,
from ./include/linux/kernel.h:22:
/home/chleroy/linux-powerpc/lib/vdso/getrandom.c:78:57: error: invalid
use of undefined type 'struct vgetrandom_opaque_params'
78 | for (size_t i = 0; i <
ARRAY_SIZE(params->reserved); ++i)
| ^~
./include/linux/build_bug.h:16:62: note: in definition of macro
'BUILD_BUG_ON_ZERO'
16 | #define BUILD_BUG_ON_ZERO(e) ((int)(sizeof(struct {
int:(-!!(e)); })))
| ^
./include/linux/compiler.h:243:51: note: in expansion of macro '__same_type'
243 | #define __must_be_array(a)
BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
| ^~~~~~~~~~~
./include/vdso/array_size.h:11:59: note: in expansion of macro
'__must_be_array'
11 | #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) +
__must_be_array(arr))
|
^~~~~~~~~~~~~~~
/home/chleroy/linux-powerpc/lib/vdso/getrandom.c:78:40: note: in
expansion of macro 'ARRAY_SIZE'
78 | for (size_t i = 0; i <
ARRAY_SIZE(params->reserved); ++i)
| ^~~~~~~~~~
/home/chleroy/linux-powerpc/lib/vdso/getrandom.c:78:57: error: invalid
use of undefined type 'struct vgetrandom_opaque_params'
78 | for (size_t i = 0; i <
ARRAY_SIZE(params->reserved); ++i)
| ^~
./include/linux/build_bug.h:16:62: note: in definition of macro
'BUILD_BUG_ON_ZERO'
16 | #define BUILD_BUG_ON_ZERO(e) ((int)(sizeof(struct {
int:(-!!(e)); })))
| ^
./include/linux/compiler.h:243:51: note: in expansion of macro '__same_type'
243 | #define __must_be_array(a)
BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
| ^~~~~~~~~~~
./include/vdso/array_size.h:11:59: note: in expansion of macro
'__must_be_array'
11 | #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) +
__must_be_array(arr))
|
^~~~~~~~~~~~~~~
/home/chleroy/linux-powerpc/lib/vdso/getrandom.c:78:40: note: in
expansion of macro 'ARRAY_SIZE'
78 | for (size_t i = 0; i <
ARRAY_SIZE(params->reserved); ++i)
| ^~~~~~~~~~
./include/linux/build_bug.h:16:51: error: bit-field '<anonymous>' width
not an integer constant
16 | #define BUILD_BUG_ON_ZERO(e) ((int)(sizeof(struct {
int:(-!!(e)); })))
| ^
./include/linux/compiler.h:243:33: note: in expansion of macro
'BUILD_BUG_ON_ZERO'
243 | #define __must_be_array(a)
BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
| ^~~~~~~~~~~~~~~~~
./include/vdso/array_size.h:11:59: note: in expansion of macro
'__must_be_array'
11 | #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) +
__must_be_array(arr))
|
^~~~~~~~~~~~~~~
/home/chleroy/linux-powerpc/lib/vdso/getrandom.c:78:40: note: in
expansion of macro 'ARRAY_SIZE'
78 | for (size_t i = 0; i <
ARRAY_SIZE(params->reserved); ++i)
| ^~~~~~~~~~
/home/chleroy/linux-powerpc/lib/vdso/getrandom.c:79:31: error: invalid
use of undefined type 'struct vgetrandom_opaque_params'
79 | params->reserved[i] = 0;
| ^~
In file included from ./include/vdso/datapage.h:7,
from /home/chleroy/linux-powerpc/lib/vdso/getrandom.c:6:
/home/chleroy/linux-powerpc/lib/vdso/getrandom.c:88:32: error:
'GRND_NONBLOCK' undeclared (first use in this function); did you mean
'MAP_NONBLOCK'?
88 | if (unlikely(flags & ~(GRND_NONBLOCK | GRND_RANDOM |
GRND_INSECURE)))
| ^~~~~~~~~~~~~
./include/linux/compiler.h:77:45: note: in definition of macro 'unlikely'
77 | # define unlikely(x) __builtin_expect(!!(x), 0)
| ^
/home/chleroy/linux-powerpc/lib/vdso/getrandom.c:88:32: note: each
undeclared identifier is reported only once for each function it appears in
88 | if (unlikely(flags & ~(GRND_NONBLOCK | GRND_RANDOM |
GRND_INSECURE)))
| ^~~~~~~~~~~~~
./include/linux/compiler.h:77:45: note: in definition of macro 'unlikely'
77 | # define unlikely(x) __builtin_expect(!!(x), 0)
| ^
/home/chleroy/linux-powerpc/lib/vdso/getrandom.c:88:48: error:
'GRND_RANDOM' undeclared (first use in this function)
88 | if (unlikely(flags & ~(GRND_NONBLOCK | GRND_RANDOM |
GRND_INSECURE)))
| ^~~~~~~~~~~
./include/linux/compiler.h:77:45: note: in definition of macro 'unlikely'
77 | # define unlikely(x) __builtin_expect(!!(x), 0)
| ^
/home/chleroy/linux-powerpc/lib/vdso/getrandom.c:88:62: error:
'GRND_INSECURE' undeclared (first use in this function)
88 | if (unlikely(flags & ~(GRND_NONBLOCK | GRND_RANDOM |
GRND_INSECURE)))
|
^~~~~~~~~~~~~
./include/linux/compiler.h:77:45: note: in definition of macro 'unlikely'
77 | # define unlikely(x) __builtin_expect(!!(x), 0)
| ^
make[2]: *** [arch/powerpc/kernel/vdso/Makefile:87:
arch/powerpc/kernel/vdso/vgetrandom-32.o] Error 1
make[1]: *** [arch/powerpc/Makefile:388: vdso_prepare] Error 2
make: *** [Makefile:227: __sub-make] Error 2

FWIW, here are the changes I added on top of your series:

diff --git a/arch/powerpc/include/asm/vdso/getrandom.h
b/arch/powerpc/include/asm/vdso/getrandom.h
index 501d6bb14e8a..4af9efdbe296 100644
--- a/arch/powerpc/include/asm/vdso/getrandom.h
+++ b/arch/powerpc/include/asm/vdso/getrandom.h
@@ -5,6 +5,8 @@
#ifndef _ASM_POWERPC_VDSO_GETRANDOM_H
#define _ASM_POWERPC_VDSO_GETRANDOM_H

+#include <vdso/datapage.h>
+
#ifndef __ASSEMBLY__

static __always_inline int do_syscall_3(const unsigned long _r0, const
unsigned long _r3,
diff --git a/arch/powerpc/include/asm/vdso/mman.h
b/arch/powerpc/include/asm/vdso/mman.h
new file mode 100644
index 000000000000..4c936c9d11ab
--- /dev/null
+++ b/arch/powerpc/include/asm/vdso/mman.h
@@ -0,0 +1,15 @@
+
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_VDSO_MMAN_H
+#define __ASM_VDSO_MMAN_H
+
+#ifndef __ASSEMBLY__
+
+#include <uapi/linux/mman.h>
+
+#define VDSO_MMAP_PROT PROT_READ | PROT_WRITE
+#define VDSO_MMAP_FLAGS MAP_DROPPABLE | MAP_ANONYMOUS
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* __ASM_VDSO_MMAN_H */
diff --git a/arch/powerpc/include/asm/vdso/page.h
b/arch/powerpc/include/asm/vdso/page.h
new file mode 100644
index 000000000000..c41fd44aca5b
--- /dev/null
+++ b/arch/powerpc/include/asm/vdso/page.h
@@ -0,0 +1,15 @@
+
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_VDSO_PAGE_H
+#define __ASM_VDSO_PAGE_H
+
+#ifndef __ASSEMBLY__
+
+#include <asm/page.h>
+
+#define VDSO_PAGE_MASK PAGE_MASK
+#define VDSO_PAGE_SIZE PAGE_SIZE
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* __ASM_VDSO_PAGE_H */

Christophe