ARM: 8431/1: fix alignement of __bug_table section entries
On old ARM chips, unaligned accesses to memory are not trapped and
fixed. On module load, symbols are relocated, and the relocation of
__bug_table symbols is done on a u32 basis. Yet the section is not
aligned to a multiple of 4 address, but to a multiple of 2.
This triggers an Oops on pxa architecture, where address 0xbf0021ea
is the first relocation in the __bug_table section :
apply_relocate(): pxa3xx_nand: section 13 reloc 0 sym ''
Unable to handle kernel paging request at virtual address
bf0021ea
pgd =
e1cd0000
[
bf0021ea] *pgd=
c1cce851, *pte=
c1cde04f, *ppte=
c1cde01f
Internal error: Oops: 23 [#1] ARM
Modules linked in:
CPU: 0 PID: 606 Comm: insmod Not tainted 4.2.0-rc8-next-
20150828-cm-x300+ #887
Hardware name: CM-X300 module
task:
e1c68700 ti:
e1c3e000 task.ti:
e1c3e000
PC is at apply_relocate+0x2f4/0x3d4
LR is at 0xbf0021ea
pc : [<
c000e7c8>] lr : [<
bf0021ea>] psr:
80000013
sp :
e1c3fe30 ip :
60000013 fp :
e49e8c60
r10:
e49e8fa8 r9 :
00000000 r8 :
e49e7c58
r7 :
e49e8c38 r6 :
e49e8a58 r5 :
e49e8920 r4 :
e49e8918
r3 :
bf0021ea r2 :
bf007034 r1 :
00000000 r0 :
bf000000
Flags: Nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none
Control:
0000397f Table:
c1cd0018 DAC:
00000051
Process insmod (pid: 606, stack limit = 0xe1c3e198)
[<
c000e7c8>] (apply_relocate) from [<
c005ce5c>] (load_module+0x1248/0x1f5c)
[<
c005ce5c>] (load_module) from [<
c005dc54>] (SyS_init_module+0xe4/0x170)
[<
c005dc54>] (SyS_init_module) from [<
c000a420>] (ret_fast_syscall+0x0/0x38)
Fix this by ensuring entries in __bug_table are all aligned to at least
of multiple of 4. This transforms a module section __bug_table as :
- [12] __bug_table PROGBITS
00000000 002232 000018 00 A 0 0 1
+ [12] __bug_table PROGBITS
00000000 002232 000018 00 A 0 0 4
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>