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authorAlexander Sverdlin <alexander.sverdlin@nokia.com>2015-07-02 17:16:01 +0200
committerRalf Baechle <ralf@linux-mips.org>2015-07-09 11:02:59 +0200
commita6335fa11e08fc386740557b2a4c1b7ff34bc499 (patch)
tree00973dc05f8e6a4e9cd7ef37975043f23cbbcfbe /arch
parentMIPS: O32: Do not handle require 32 bytes from the stack to be readable. (diff)
downloadlinux-a6335fa11e08fc386740557b2a4c1b7ff34bc499.tar.xz
linux-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')
-rw-r--r--arch/mips/kernel/setup.c13
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.
*/