in do_mmap_pgoff() (2.4.19-preX)
Hi,
While documenting the do_mmap_pgoff() function, i found this
snippet of code very suspicious:
/* Private writable mapping? Check memory availability.. */
if ((vm_flags & (VM_SHARED | VM_WRITE)) == VM_WRITE &&
!(flags & MAP_NORESERVE) &&
!vm_enough_memory(len >> PAGE_SHIFT))
return -ENOMEM;
Here we need to quit if *any* one of the condition is true. So Ithink it should be "||" instead of "&&". As according to the present code, it quits only if all the 3 conditions is true, which is wrong.
Bye,
Abhi.
Linux Kernel Documentation Project
http://freesoftware.fsf.org/lkdp
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Quoted 10 lines · Abhishek Nayani
While documenting the
do_mmap_pgoff()function, i found this
snippet of code very suspicious:/* Private writable mapping? Check memory availability.. */ if ((vm_flags & (VM_SHARED | VM_WRITE)) == VM_WRITE && !(flags & MAP_NORESERVE) && !vm_enough_memory(len >> PAGE_SHIFT)) return -ENOMEM; Here we need to quit if *any* one of the condition is true. So I
Quoted 2 lines
think it should be "||" instead of "&&". As according to the present code, it quits only if all the 3 conditions is true, which is wrong.
No, the code is correct.
The only case where we end up allocating new pages for this mapping is when the mapping is both writable and private.
Read-only mappings and shared mappings always have backing store, the file from which the mapping comes and empty_zero_page.
regards,
Rik
Signature · 8 lines
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