Re: [PATCHv4 08/10] mm/kasan: Switch to using __pa_symbol and lm_alias

From: Mark Rutland
Date: Tue Dec 06 2016 - 14:20:37 EST


On Tue, Nov 29, 2016 at 10:55:27AM -0800, Laura Abbott wrote:
> @@ -94,7 +94,7 @@ static void __init zero_pud_populate(pgd_t *pgd, unsigned long addr,
>
> pud_populate(&init_mm, pud, kasan_zero_pmd);

We also need to lm_alias()-ify kasan_zero_pmd here, or we'll get a
stream of warnings at boot (example below).

I should have spotted that. :/

With that fixed up, I'm able to boot Juno with both KASAN_INLINE and
DEBUG_VIRTUAL, without issued. With that, my previous Reviewed-by and Tested-by
stand.

Thanks,
Mark.

---->8----

[ 0.000000] virt_to_phys used for non-linear address :ffff20000a367000
[ 0.000000] ------------[ cut here ]------------
[ 0.000000] WARNING: CPU: 0 PID: 0 at arch/arm64/mm/physaddr.c:13 __virt_to_phys+0x48/0x68
[ 0.000000] Modules linked in:
[ 0.000000]
[ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.9.0-rc6-00012-gdcc0162-dirty #13
[ 0.000000] Hardware name: ARM Juno development board (r1) (DT)
[ 0.000000] task: ffff200009ec2200 task.stack: ffff200009eb0000
[ 0.000000] PC is at __virt_to_phys+0x48/0x68
[ 0.000000] LR is at __virt_to_phys+0x48/0x68
[ 0.000000] pc : [<ffff2000080af310>] lr : [<ffff2000080af310>] pstate: 600000c5
[ 0.000000] sp : ffff200009eb3c80
[ 0.000000] x29: ffff200009eb3c80 x28: ffff20000abdd000
[ 0.000000] x27: ffff200009ce1000 x26: ffff047fffffffff
[ 0.000000] x25: ffff200009ce1000 x24: ffff20000a366100
[ 0.000000] x23: ffff048000000000 x22: ffff20000a366000
[ 0.000000] x21: ffff040080000000 x20: ffff040040000000
[ 0.000000] x19: ffff20000a367000 x18: 000000000000005c
[ 0.000000] x17: 00000009ffec20e0 x16: 00000000fefff4b0
[ 0.000000] x15: ffffffffffffffff x14: 302b646d705f6f72
[ 0.000000] x13: 657a5f6e6173616b x12: 2820303030373633
[ 0.000000] x11: ffff20000a376ca0 x10: 0000000000000010
[ 0.000000] x9 : 646461207261656e x8 : 696c2d6e6f6e2072
[ 0.000000] x7 : 6f66206465737520 x6 : ffff20000a3741e5
[ 0.000000] x5 : 1fffe4000146ee0e x4 : 1fffe400013de704
[ 0.000000] x3 : 1fffe400013d6003 x2 : 1fffe400013d6003
[ 0.000000] x1 : 0000000000000000 x0 : 0000000000000056
[ 0.000000]
[ 0.000000] ---[ end trace 0000000000000000 ]---
[ 0.000000] Call trace:
[ 0.000000] Exception stack(0xffff200009eb3a50 to 0xffff200009eb3b80)
[ 0.000000] 3a40: ffff20000a367000 0001000000000000
[ 0.000000] 3a60: ffff200009eb3c80 ffff2000080af310 00000000600000c5 000000000000003d
[ 0.000000] 3a80: ffff200009ce1000 ffff2000081c4720 0000000041b58ab3 ffff200009c6cd98
[ 0.000000] 3aa0: ffff2000080818a0 ffff20000a366000 ffff048000000000 ffff20000a366100
[ 0.000000] 3ac0: ffff200009ce1000 ffff047fffffffff ffff200009ce1000 ffff20000abdd000
[ 0.000000] 3ae0: ffff0400013e3ccf ffff20000a3766c0 0000000000000000 0000000000000000
[ 0.000000] 3b00: ffff200009eb3c80 ffff200009eb3c80 ffff200009eb3c40 00000000ffffffc8
[ 0.000000] 3b20: ffff200009eb3b50 ffff2000082cbd3c ffff200009eb3c80 ffff200009eb3c80
[ 0.000000] 3b40: ffff200009eb3c40 00000000ffffffc8 0000000000000056 0000000000000000
[ 0.000000] 3b60: 1fffe400013d6003 1fffe400013d6003 1fffe400013de704 1fffe4000146ee0e
[ 0.000000] [<ffff2000080af310>] __virt_to_phys+0x48/0x68
[ 0.000000] [<ffff200009d734e8>] zero_pud_populate+0x88/0x138
[ 0.000000] [<ffff200009d736f8>] kasan_populate_zero_shadow+0x160/0x18c
[ 0.000000] [<ffff200009d5a048>] kasan_init+0x1f8/0x408
[ 0.000000] [<ffff200009d54000>] setup_arch+0x314/0x948
[ 0.000000] [<ffff200009d50c64>] start_kernel+0xb4/0x54c
[ 0.000000] [<ffff200009d501e0>] __primary_switched+0x64/0x74

[mark@leverpostej:~/src/linux]% uselinaro 15.08 aarch64-linux-gnu-readelf -s vmlinux | grep ffff20000a367000
108184: ffff20000a367000 4096 OBJECT GLOBAL DEFAULT 25 kasan_zero_pmd

[mark@leverpostej:~/src/linux]% uselinaro 15.08 aarch64-linux-gnu-addr2line -ife vmlinux ffff200009d734e8
set_pud
/home/mark/src/linux/./arch/arm64/include/asm/pgtable.h:435
__pud_populate
/home/mark/src/linux/./arch/arm64/include/asm/pgalloc.h:47
pud_populate
/home/mark/src/linux/./arch/arm64/include/asm/pgalloc.h:52
zero_pud_populate
/home/mark/src/linux/mm/kasan/kasan_init.c:95