This is a note to let you know that I've just added the patch titled
selftests: vDSO: fix vDSO symbols lookup for powerpc64
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
selftests-vdso-fix-vdso-symbols-lookup-for-powerpc64.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit db8ccbabb753dd364b17fc3dc2975b398e2ee78a
Author: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Date: Fri Aug 30 14:28:37 2024 +0200
selftests: vDSO: fix vDSO symbols lookup for powerpc64
[ Upstream commit ba83b3239e657469709d15dcea5f9b65bf9dbf34 ]
On powerpc64, following tests fail locating vDSO functions:
~ # ./vdso_test_abi
TAP version 13
1..16
# [vDSO kselftest] VDSO_VERSION: LINUX_2.6.15
# Couldn't find __kernel_gettimeofday
ok 1 # SKIP __kernel_gettimeofday
# clock_id: CLOCK_REALTIME
# Couldn't find __kernel_clock_gettime
ok 2 # SKIP __kernel_clock_gettime CLOCK_REALTIME
# Couldn't find __kernel_clock_getres
ok 3 # SKIP __kernel_clock_getres CLOCK_REALTIME
...
# Couldn't find __kernel_time
ok 16 # SKIP __kernel_time
# Totals: pass:0 fail:0 xfail:0 xpass:0 skip:16 error:0
~ # ./vdso_test_getrandom
__kernel_getrandom is missing!
~ # ./vdso_test_gettimeofday
Could not find __kernel_gettimeofday
~ # ./vdso_test_getcpu
Could not find __kernel_getcpu
On powerpc64, as shown below by readelf, vDSO functions symbols have
type NOTYPE, so also accept that type when looking for symbols.
$ powerpc64-linux-gnu-readelf -a arch/powerpc/kernel/vdso/vdso64.so.dbg
ELF Header:
Magic: 7f 45 4c 46 02 02 01 00 00 00 00 00 00 00 00 00
Class: ELF64
Data: 2's complement, big endian
Version: 1 (current)
OS/ABI: UNIX - System V
ABI Version: 0
Type: DYN (Shared object file)
Machine: PowerPC64
Version: 0x1
...
Symbol table '.dynsym' contains 12 entries:
Num: Value Size Type Bind Vis Ndx Name
0: 0000000000000000 0 NOTYPE LOCAL DEFAULT UND
1: 0000000000000524 84 NOTYPE GLOBAL DEFAULT 8 __[...]@@LINUX_2.6.15
2: 00000000000005f0 36 NOTYPE GLOBAL DEFAULT 8 __[...]@@LINUX_2.6.15
3: 0000000000000578 68 NOTYPE GLOBAL DEFAULT 8 __[...]@@LINUX_2.6.15
4: 0000000000000000 0 OBJECT GLOBAL DEFAULT ABS LINUX_2.6.15
5: 00000000000006c0 48 NOTYPE GLOBAL DEFAULT 8 __[...]@@LINUX_2.6.15
6: 0000000000000614 172 NOTYPE GLOBAL DEFAULT 8 __[...]@@LINUX_2.6.15
7: 00000000000006f0 84 NOTYPE GLOBAL DEFAULT 8 __[...]@@LINUX_2.6.15
8: 000000000000047c 84 NOTYPE GLOBAL DEFAULT 8 __[...]@@LINUX_2.6.15
9: 0000000000000454 12 NOTYPE GLOBAL DEFAULT 8 __[...]@@LINUX_2.6.15
10: 00000000000004d0 84 NOTYPE GLOBAL DEFAULT 8 __[...]@@LINUX_2.6.15
11: 00000000000005bc 52 NOTYPE GLOBAL DEFAULT 8 __[...]@@LINUX_2.6.15
Symbol table '.symtab' contains 56 entries:
Num: Value Size Type Bind Vis Ndx Name
...
45: 0000000000000000 0 OBJECT GLOBAL DEFAULT ABS LINUX_2.6.15
46: 00000000000006c0 48 NOTYPE GLOBAL DEFAULT 8 __kernel_getcpu
47: 0000000000000524 84 NOTYPE GLOBAL DEFAULT 8 __kernel_clock_getres
48: 00000000000005f0 36 NOTYPE GLOBAL DEFAULT 8 __kernel_get_tbfreq
49: 000000000000047c 84 NOTYPE GLOBAL DEFAULT 8 __kernel_gettimeofday
50: 0000000000000614 172 NOTYPE GLOBAL DEFAULT 8 __kernel_sync_dicache
51: 00000000000006f0 84 NOTYPE GLOBAL DEFAULT 8 __kernel_getrandom
52: 0000000000000454 12 NOTYPE GLOBAL DEFAULT 8 __kernel_sigtram[...]
53: 0000000000000578 68 NOTYPE GLOBAL DEFAULT 8 __kernel_time
54: 00000000000004d0 84 NOTYPE GLOBAL DEFAULT 8 __kernel_clock_g[...]
55: 00000000000005bc 52 NOTYPE GLOBAL DEFAULT 8 __kernel_get_sys[...]
Fixes: 98eedc3a9dbf ("Document the vDSO and add a reference parser")
Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Acked-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/tools/testing/selftests/vDSO/parse_vdso.c b/tools/testing/selftests/vDSO/parse_vdso.c
index 9ef3ad3789c17..540f9a284e9f0 100644
--- a/tools/testing/selftests/vDSO/parse_vdso.c
+++ b/tools/testing/selftests/vDSO/parse_vdso.c
@@ -238,7 +238,8 @@ void *vdso_sym(const char *version, const char *name)
ELF(Sym) *sym = &vdso_info.symtab[chain];
/* Check for a defined global or weak function w/ right name. */
- if (ELF64_ST_TYPE(sym->st_info) != STT_FUNC)
+ if (ELF64_ST_TYPE(sym->st_info) != STT_FUNC &&
+ ELF64_ST_TYPE(sym->st_info) != STT_NOTYPE)
continue;
if (ELF64_ST_BIND(sym->st_info) != STB_GLOBAL &&
ELF64_ST_BIND(sym->st_info) != STB_WEAK)
