p71924506
/
linux_old1
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

ARM: 8700/1: nommu: always reserve address 0 away 

Some nommu systems have RAM at address 0. When vectors are not located
there, the very beginning of memory remains available for dynamic
allocations. The memblock allocator explicitly skips the first page
but the standard page allocator does not, and while it correctly returns
a non-null struct page pointer for that page, page_address() gives 0
which gets confused with NULL (out of memory) by callers despite having
plenty of free memory left.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
This commit is contained in:
Nicolas Pitre 2017-10-01 02:06:27 +01:00 committed by Russell King
parent 2bd6bf03f4
commit 195320fd6e
1 changed files with 5 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
arch/arm/mm/nommu.c
View File

@ -344,6 +344,11 @@ void __init arm_mm_memblock_reserve(void)
* reserved here. * reserved here.
*/ */
#endif #endif
/*
* In any case, always ensure address 0 is never used as many things
* get very confused if 0 is returned as a legitimate address.
*/
memblock_reserve(0, 1);
} }
void __init adjust_lowmem_bounds(void) void __init adjust_lowmem_bounds(void)