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| author |   Alexander Sverdlin <alexander.sverdlin@nokia.com> | 2015-07-02 17:16:01 +0200 |
|---|---|---|
| committer |   Ralf Baechle <ralf@linux-mips.org> | 2015-07-09 11:02:59 +0200 |
| commit | a6335fa11e08fc386740557b2a4c1b7ff34bc499 (patch) | |
| tree | 00973dc05f8e6a4e9cd7ef37975043f23cbbcfbe /arch/mips | |
| parent | MIPS: O32: Do not handle require 32 bytes from the stack to be readable. (diff) | |
| download | linux-dev-a6335fa11e08fc386740557b2a4c1b7ff34bc499.tar.xz linux-dev-a6335fa11e08fc386740557b2a4c1b7ff34bc499.zip | |
MIPS: bootmem: Don't use memory holes for page bitmap
Commit f9a7febd leads to a fact that mapstart and therefore a page bitmap for
bootmem allocator immediately follows initrd_end. This doesn't always work
well on Octeon, where there are holes in PFN ranges (refer to 5b3b1688 and
4MB-aligned PFN allocation). Depending on the inird location it could happen,
that mapstart would be in an area not allocated by plat_mem_setup() in
arch/mips/cavium-octeon/setup.c, but in the alignment hole between initrd and
the next PFN area. Later on this memory will be unconditionally made available
to buddy allocator at the end of free_all_bootmem_core() (mm/bootmem.c).
All of this results in Linux using the memory not designated for Linux in
Octeon's plat_mem_setup(), which in turn means corruption of the memory used
by another OS/baremetal code on the same SoC.
It doesn't look to me as a problem of Octeon platform code, but rather as an
inability of f9a7febd to deal correctly with the fragmented memory-mappings.
Proposed fix moves the check for initrd address to the same calculation-loop
in bootmem_init() (arch/mips/kernel/setup.c), which also accounts for kernel
code location. This should result in mapstart located starting from the first
PFN area after kernel code AND initrd.
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Cc: linux-mips@linux-mips.org
Cc: David Daney <david.daney@cavium.com>
Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Andreas Herrmann <andreas.herrmann@caviumnetworks.com>
Cc: Joe Perches <joe@perches.com>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Yusuf Khan <yusuf.khan@nokia.com>
Cc: Michael Kreuzer <michael.kreuzer@nokia.com>
Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Patchwork: https://patchwork.linux-mips.org/patch/10594/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips')
| -rw-r--r-- | arch/mips/kernel/setup.c | 13 |
1 files changed, 5 insertions, 8 deletions
diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c index be73c491182b..008b3378653a 100644 --- a/arch/mips/kernel/setup.c +++ b/arch/mips/kernel/setup.c @@ -337,6 +337,11 @@ static void __init bootmem_init(void) min_low_pfn = start; if (end <= reserved_end) continue; +#ifdef CONFIG_BLK_DEV_INITRD + /* mapstart should be after initrd_end */ + if (initrd_end && end <= (unsigned long)PFN_UP(__pa(initrd_end))) + continue; +#endif if (start >= mapstart) continue; mapstart = max(reserved_end, start); @@ -366,14 +371,6 @@ static void __init bootmem_init(void) max_low_pfn = PFN_DOWN(HIGHMEM_START); } -#ifdef CONFIG_BLK_DEV_INITRD - /* - * mapstart should be after initrd_end - */ - if (initrd_end) - mapstart = max(mapstart, (unsigned long)PFN_UP(__pa(initrd_end))); -#endif - /* * Initialize the boot-time allocator with low memory only. */ |