Do not cast -1 to uint64 in EnableKernelMemoryAccounting #1493
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This fixes a runc bug that is very annoying on kernels such as RHEL 7.2 that have the following bug: when setting memory.kmem.limit_in_bytes to a bigger value than the default max value (bigger than 2^63-1), the buggy kernel sets it to 0, instead of setting it to the max value. This results in the process being unable to run with a 0 byte limit on kmem. That kernel bug exposes a runc bug introduced in 8430cc4, that casted an int64(-1) to uint64 in EnableKernelMemoryAccounting, which is called every time the user specifies any memory-related cgroup setting as determined by the memoryAssigned function. This patch is the smallest fix for this clearly unwanted behavior. Reverting 8430cc4, although desirable because int64 values are casted to uint64 in many other places introducing similar bugs, it is out of scope for this patch since it would require a spec change. Signed-off-by: Tibor Vass <[email protected]>
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Lets revert the entire commit for now in your other PR. |
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This fixes a runc bug that is very annoying on kernels such as RHEL 7.2
that have the following bug: when setting memory.kmem.limit_in_bytes to
a bigger value than the default max value (bigger than 2^63-1), the
buggy kernel sets it to 0, instead of setting it to the max value. This
results in the process being unable to run with a 0 byte limit on kmem.
That kernel bug exposes a runc bug introduced in 8430cc4, that casted an
int64(-1) to uint64 in EnableKernelMemoryAccounting, which is called
every time the user specifies any memory-related cgroup setting as
determined by the memoryAssigned function.
This patch is the smallest fix for this clearly unwanted behavior.
Reverting 8430cc4, although desirable because int64 values are casted to
uint64 in many other places introducing similar bugs, it is out of scope
for this patch since it would require a spec change.
Signed-off-by: Tibor Vass [email protected]
Related #1492 #1375
cc @crosbymichael @justincormack @tonistiigi @hqhq