diff options
| author | Christophe Leroy <christophe.leroy@c-s.fr> | 2020-01-24 11:54:41 +0000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-01-28 23:13:44 +1100 |
| commit | 1d8f739b07bd538f272f60bf53f10e7e6248d295 (patch) | |
| tree | a9664a6d9b8c642fcf85f8da062da593508dd711 /arch/powerpc/include/asm/uaccess.h | |
| parent | 6ec20aa2e510b6297906c45f009aa08b2d97269a (diff) | |
powerpc/kuap: Fix set direction in allow/prevent_user_access()
__builtin_constant_p() always return 0 for pointers, so on RADIX
we always end up opening both direction (by writing 0 in SPR29):
0000000000000170 <._copy_to_user>:
...
1b0: 4c 00 01 2c isync
1b4: 39 20 00 00 li r9,0
1b8: 7d 3d 03 a6 mtspr 29,r9
1bc: 4c 00 01 2c isync
1c0: 48 00 00 01 bl 1c0 <._copy_to_user+0x50>
1c0: R_PPC64_REL24 .__copy_tofrom_user
...
0000000000000220 <._copy_from_user>:
...
2ac: 4c 00 01 2c isync
2b0: 39 20 00 00 li r9,0
2b4: 7d 3d 03 a6 mtspr 29,r9
2b8: 4c 00 01 2c isync
2bc: 7f c5 f3 78 mr r5,r30
2c0: 7f 83 e3 78 mr r3,r28
2c4: 48 00 00 01 bl 2c4 <._copy_from_user+0xa4>
2c4: R_PPC64_REL24 .__copy_tofrom_user
...
Use an explicit parameter for direction selection, so that GCC
is able to see it is a constant:
00000000000001b0 <._copy_to_user>:
...
1f0: 4c 00 01 2c isync
1f4: 3d 20 40 00 lis r9,16384
1f8: 79 29 07 c6 rldicr r9,r9,32,31
1fc: 7d 3d 03 a6 mtspr 29,r9
200: 4c 00 01 2c isync
204: 48 00 00 01 bl 204 <._copy_to_user+0x54>
204: R_PPC64_REL24 .__copy_tofrom_user
...
0000000000000260 <._copy_from_user>:
...
2ec: 4c 00 01 2c isync
2f0: 39 20 ff ff li r9,-1
2f4: 79 29 00 04 rldicr r9,r9,0,0
2f8: 7d 3d 03 a6 mtspr 29,r9
2fc: 4c 00 01 2c isync
300: 7f c5 f3 78 mr r5,r30
304: 7f 83 e3 78 mr r3,r28
308: 48 00 00 01 bl 308 <._copy_from_user+0xa8>
308: R_PPC64_REL24 .__copy_tofrom_user
...
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Spell out the directions, s/KUAP_R/KUAP_READ/ etc.]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f4e88ec4941d5facb35ce75026b0112f980086c3.1579866752.git.christophe.leroy@c-s.fr
Diffstat (limited to 'arch/powerpc/include/asm/uaccess.h')
| -rw-r--r-- | arch/powerpc/include/asm/uaccess.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h index c92fe7fe9692..cafad1960e76 100644 --- a/arch/powerpc/include/asm/uaccess.h +++ b/arch/powerpc/include/asm/uaccess.h @@ -313,9 +313,9 @@ raw_copy_in_user(void __user *to, const void __user *from, unsigned long n) unsigned long ret; barrier_nospec(); - allow_user_access(to, from, n); + allow_read_write_user(to, from, n); ret = __copy_tofrom_user(to, from, n); - prevent_user_access(to, from, n); + prevent_read_write_user(to, from, n); return ret; } #endif /* __powerpc64__ */ |