kernel/git/stable/linux.git/mm/percpu.c, branch linux-2.6.34.y

Revert "percpu: fix chunk range calculation"

2014-02-10T21:10:41+00:00

This reverts commit 264266e6897dd81c894d1c5cbd90b133707b32f3. The backport had dependencies on other mm/percpu.c restructurings, like those in commit 020ec6537aa65c18e9084c568d7b94727f2026fd ("percpu: factor out pcpu_addr_in_first/reserved_chunk() and update per_cpu_ptr_to_phys()"). Rather than drag in more changes, we simply revert the incomplete backport. Reported-by: George G. Davis Signed-off-by: Paul Gortmaker

percpu: fix chunk range calculation

2013-01-16T21:45:03+00:00

commit a855b84c3d8c73220d4d3cd392a7bee7c83de70e upstream. Percpu allocator recorded the cpus which map to the first and last units in pcpu_first/last_unit_cpu respectively and used them to determine the address range of a chunk - e.g. it assumed that the first unit has the lowest address in a chunk while the last unit has the highest address. This simply isn't true. Groups in a chunk can have arbitrary positive or negative offsets from the previous one and there is no guarantee that the first unit occupies the lowest offset while the last one the highest. Fix it by actually comparing unit offsets to determine cpus occupying the lowest and highest offsets. Also, rename pcu_first/last_unit_cpu to pcpu_low/high_unit_cpu to avoid confusion. The chunk address range is used to flush cache on vmalloc area map/unmap and decide whether a given address is in the first chunk by per_cpu_ptr_to_phys() and the bug was discovered by invalid per_cpu_ptr_to_phys() translation for crash_note. Kudos to Dave Young for tracking down the problem. Signed-off-by: Tejun Heo Reported-by: WANG Cong Reported-by: Dave Young Tested-by: Dave Young LKML-Reference: <4EC21F67.10905@redhat.com> Signed-off-by: Paul Gortmaker

percpu: fix first chunk match in per_cpu_ptr_to_phys()

2013-01-16T21:45:03+00:00

commit 9983b6f0cf8263e51bcf4c8a9dc0c1ef175b3c60 upstream. per_cpu_ptr_to_phys() determines whether the passed in @addr belongs to the first_chunk or not by just matching the address against the address range of the base unit (unit0, used by cpu0). When an adress from another cpu was passed in, it will always determine that the address doesn't belong to the first chunk even when it does. This makes the function return a bogus physical address which may lead to crash. This problem was discovered by Cliff Wickman while investigating a crash during kdump on a SGI UV system. Signed-off-by: Tejun Heo Reported-by: Cliff Wickman Tested-by: Cliff Wickman [PG: for 2.6.34, diffstat differs slightly due to a trivial indenting difference, and 34 does not have the _maybe_unused annotation to delete] Signed-off-by: Paul Gortmaker

percpu: fix pcpu_last_unit_cpu

2011-01-06T23:08:00+00:00

commit 46b30ea9bc3698bc1d1e6fd726c9601d46fa0a91 upstream. pcpu_first/last_unit_cpu are used to track which cpu has the first and last units assigned. This in turn is used to determine the span of a chunk for man/unmap cache flushes and whether an address belongs to the first chunk or not in per_cpu_ptr_to_phys(). When the number of possible CPUs isn't power of two, a chunk may contain unassigned units towards the end of a chunk. The logic to determine pcpu_last_unit_cpu was incorrect when there was an unused unit at the end of a chunk. It failed to ignore the unused unit and assigned the unused marker NR_CPUS to pcpu_last_unit_cpu. This was discovered through kdump failure which was caused by malfunctioning per_cpu_ptr_to_phys() on a kvm setup with 50 possible CPUs by CAI Qian. Signed-off-by: Tejun Heo Reported-by: CAI Qian Signed-off-by: Paul Gortmaker

percpu, module: implement and use is_kernel/module_percpu_address()

2010-03-29T14:07:12+00:00

lockdep has custom code to check whether a pointer belongs to static percpu area which is somewhat broken. Implement proper is_kernel/module_percpu_address() and replace the custom code. On UP, percpu variables are regular static variables and can't be distinguished from them. Always return %false on UP. Signed-off-by: Tejun Heo Acked-by: Peter Zijlstra Cc: Rusty Russell Cc: Ingo Molnar

percpu: add __percpu sparse annotations to core kernel subsystems

2010-02-17T02:17:38+00:00

Add __percpu sparse annotations to core subsystems. These annotations are to make sparse consider percpu variables to be in a different address space and warn if accessed without going through percpu accessors. This patch doesn't affect normal builds. Signed-off-by: Tejun Heo Reviewed-by: Christoph Lameter Acked-by: Paul E. McKenney Cc: Jens Axboe Cc: linux-mm@kvack.org Cc: Rusty Russell Cc: Dipankar Sarma Cc: Peter Zijlstra Cc: Andrew Morton Cc: Eric Biederman

Merge branch 'master' into percpu

2010-02-02T05:38:15+00:00

percpu: avoid calling __pcpu_ptr_to_addr(NULL)

2010-01-11T17:34:04+00:00

__pcpu_ptr_to_addr() can be overridden by the architecture and might not behave well if passed a NULL pointer. So avoid calling it until we have verified that its arg is not NULL. Cc: Rusty Russell Cc: Kamalesh Babulal Acked-by: Tejun Heo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'master' into percpu

2010-01-05T00:17:33+00:00

Conflicts: arch/powerpc/platforms/pseries/hvCall.S include/linux/percpu.h

percpu: refactor the code in pcpu_[de]populate_chunk()

2009-12-08T01:28:54+00:00

Using break statement at the end of a for loop is confusing, refactor it by replacing the for loop. Signed-off-by: WANG Cong Signed-off-by: Tejun Heo