Commit graph

3 commits

Author SHA1 Message Date
Kumar Gala
da3de6df33 [POWERPC] Fix -Os kernel builds with newer gcc versions
GCC 4.4.x looks to be adding support for generating out-of-line register
saves/restores based on:

http://gcc.gnu.org/ml/gcc-patches/2008-04/msg01678.html

This breaks the kernel if we enable CONFIG_CC_OPTIMIZE_FOR_SIZE.  To fix
this we add the use the save/restore code from gcc and simplified it down
for our needs (integer only).

Additionally, we have to link this code into each module.  The other
solution was to add EXPORT_SYMBOL() which meant going through the
trampoline which seemed nonsensical for these out-of-line routines.

Finally, we add some checks to prom_init_check.sh to ignore the
out-of-line save/restore functions.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-16 15:00:54 +10:00
Michael Ellerman
d1e8d50d5a [POWERPC] Add kernstart_addr to list of allowed symbols in prom_init
Since commit "85xx: Add support for relocatable kernel (and
booting at non-zero)" (37dd2badcf),
PHYSICAL_START is #defined as kernstart_addr if RELOCATABLE
and FLATMEM is enabled.

PHYSICAL_START is used in prom_init.c and so kernstart_addr
needs to be added to the list of allowed symbols that
prom_init.c can access.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-05-23 16:15:35 +10:00
Michael Ellerman
5c02cd2fb8 [POWERPC] Discourage people from fiddling with kernel data from prom_init
As BenH said the other day, it is an "accident" that prom_init.o is
linked with the rest of the kernel.  The truth is a little more
subtle, prom_init isn't truly bootloader, it does access kernel data
in a few places.

What we can do is discourage people from adding new code that accesses
data outside of prom_init.  And hence this patch; from the script:

 # This script checks prom_init.o to see what external symbols it
 # is using, if it finds symbols not in the whitelist it returns
 # an error. The point of this is to discourage people from
 # intentionally or accidentally adding new code to prom_init.c
 # which has side effects on other parts of the kernel.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-24 20:58:03 +10:00