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| author | John Baldwin <jhb@FreeBSD.org> | 2018-01-04 21:59:34 +0000 |
|---|---|---|
| committer | John Baldwin <jhb@FreeBSD.org> | 2018-01-04 21:59:34 +0000 |
| commit | 3160862437caedbf0bfd7a4f2bb936397ab81fd9 (patch) | |
| tree | 51b4a6d7a607167e8e9b142ee74f3f301f1b1fb8 /sys/kern | |
| parent | 8e04fe5af3800d1710ff6d5e1d7c210839bbf5e2 (diff) | |
| download | src-3160862437caedbf0bfd7a4f2bb936397ab81fd9.tar.gz src-3160862437caedbf0bfd7a4f2bb936397ab81fd9.zip | |
Report offset relative to the backing object for kinfo_vmentry structures.
For the pathname reported in kinfo_vmentry structures (kve_path), the
sysctl handlers walk the object chain to find the bottom-most VM object.
This permits a COW mapping of a file with dirty pages to report the
pathname of the originally mapped file. Do the same for the object
offset (kve_offset) computing a cumulative offset during the same object
walk so that the reported offset is relative to the reported pathname.
Note that ptrace(PT_VM_ENTRY) already returns a cumulative offset
rather than the raw offset of the VM map entry.
Note also that this does not affect procstat -v output (even structured
output) since that output does not include the kve_offset field.
Reviewed by: kib
MFC after: 2 weeks
Sponsored by: DARPA / AFRL
Differential Revision: https://reviews.freebsd.org/D13767
Notes
Notes:
svn path=/head/; revision=327561
Diffstat (limited to 'sys/kern')
| -rw-r--r-- | sys/kern/kern_proc.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/sys/kern/kern_proc.c b/sys/kern/kern_proc.c index 723d82955006..11e09e3687ec 100644 --- a/sys/kern/kern_proc.c +++ b/sys/kern/kern_proc.c @@ -2159,8 +2159,10 @@ sysctl_kern_proc_ovmmap(SYSCTL_HANDLER_ARGS) } for (lobj = tobj = obj; tobj; tobj = tobj->backing_object) { - if (tobj != obj) + if (tobj != obj) { VM_OBJECT_RLOCK(tobj); + kve->kve_offset += tobj->backing_object_offset; + } if (lobj != obj) VM_OBJECT_RUNLOCK(lobj); lobj = tobj; @@ -2168,7 +2170,7 @@ sysctl_kern_proc_ovmmap(SYSCTL_HANDLER_ARGS) kve->kve_start = (void*)entry->start; kve->kve_end = (void*)entry->end; - kve->kve_offset = (off_t)entry->offset; + kve->kve_offset += (off_t)entry->offset; if (entry->protection & VM_PROT_READ) kve->kve_protection |= KVME_PROT_READ; @@ -2389,6 +2391,7 @@ kern_proc_vmmap_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, int flags) for (tobj = obj; tobj != NULL; tobj = tobj->backing_object) { VM_OBJECT_RLOCK(tobj); + kve->kve_offset += tobj->backing_object_offset; lobj = tobj; } if (obj->backing_object == NULL) @@ -2409,7 +2412,7 @@ kern_proc_vmmap_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, int flags) kve->kve_start = entry->start; kve->kve_end = entry->end; - kve->kve_offset = entry->offset; + kve->kve_offset += entry->offset; if (entry->protection & VM_PROT_READ) kve->kve_protection |= KVME_PROT_READ; |