[LibOS] Fix bug of RLIMIT_STACK being overwritten in child
#1976
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This manifest option allows to modify the original `RLIMIT_NOFILE` resource limit. There is *no* way to propagate this limit from the host; this is a deliberate design choice. Signed-off-by: Dmitrii Kuvaiskii <[email protected]>
Signed-off-by: Dmitrii Kuvaiskii <[email protected]>
Previously, the resource limit `RLIMIT_STACK` (maximum size of the process stack, in bytes) was overwritten in the child process, after fork. Thus, if the parent used `setrlimit(RLIMIT_STACK)`, the effect of this was lost in the child. This commit fixes this bug, and adds a LibOS test to verify the correct behavior. Signed-off-by: Dmitrii Kuvaiskii <[email protected]>
dimakuv
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Aug 19, 2024
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Reviewable status: 0 of 7 files reviewed, 2 unresolved discussions, not enough approvals from maintainers (2 more required), not enough approvals from different teams (1 more required, approved so far: Intel)
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This PR is based on top of #1973, thus requires that one to be merged first.
libos/src/libos_init.c line 303 at r1 (raw file):
return 0; stack_size = ALLOC_ALIGN_UP(stack_size);
Note that stack size doesn't need to be aligned when setting the resource limit RLIMIT_STACK. That's what Linux does -- it doesn't silently adjust the stack size, instead Linux just writes whatever stack size the user supplies to it.
Thus I moved this alignment of the stack further down in this function.
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Description of the changes
Previously, the resource limit
RLIMIT_STACK(maximum size of the process stack, in bytes) was overwritten in the child process, after fork. Thus, if the parent usedsetrlimit(RLIMIT_STACK), the effect of this was lost in the child. This PR fixes this bug, and adds a LibOS test to verify the correct behavior.Fixes #1974
Noticed while reviewing #1973.
How to test this PR?
New LibOS test was added.
This change is