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authorKonstantin Belousov <kib@FreeBSD.org>2020-12-31 22:29:40 +0000
committerKonstantin Belousov <kib@FreeBSD.org>2021-01-10 02:41:20 +0000
commit4daea938130b4a219e01d678e9499f0bdb715f82 (patch)
treef404049a57daf52ea4e78800470ac19f691b3c58 /sys
parenta008bdeda3b8278fe600cf83ecf44acd1ccb30b6 (diff)
downloadsrc-4daea938130b4a219e01d678e9499f0bdb715f82.tar.gz
src-4daea938130b4a219e01d678e9499f0bdb715f82.zip
Lock proctree in around fill_kinfo_proc().
Proctree lock is needed for correct calculation and collection of the job-control related data in kinfo_proc. There was even an XXX comment about it. Satisfy locking and lock ordering requirements by taking proctree lock around pass over each bucket in proc_iterate(), and in sysctl_kern_proc() and note_procstat_proc() for individual process reporting. Reviewed by: jilles Tested by: pho MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D27871
Diffstat (limited to 'sys')
-rw-r--r--sys/kern/imgact_elf.c2
-rw-r--r--sys/kern/kern_proc.c5
2 files changed, 7 insertions, 0 deletions
diff --git a/sys/kern/imgact_elf.c b/sys/kern/imgact_elf.c
index f6482bfcfb21..4f5d5a9a0736 100644
--- a/sys/kern/imgact_elf.c
+++ b/sys/kern/imgact_elf.c
@@ -2386,8 +2386,10 @@ __elfN(note_procstat_proc)(void *arg, struct sbuf *sb, size_t *sizep)
KASSERT(*sizep == size, ("invalid size"));
structsize = sizeof(elf_kinfo_proc_t);
sbuf_bcat(sb, &structsize, sizeof(structsize));
+ sx_slock(&proctree_lock);
PROC_LOCK(p);
kern_proc_out(p, sb, ELF_KERN_PROC_MASK);
+ sx_sunlock(&proctree_lock);
}
*sizep = size;
}
diff --git a/sys/kern/kern_proc.c b/sys/kern/kern_proc.c
index fab1df795799..c63d136a3046 100644
--- a/sys/kern/kern_proc.c
+++ b/sys/kern/kern_proc.c
@@ -1653,6 +1653,7 @@ proc_iterate(int (*cb)(struct proc *, void *), void *cbarg)
int error, i, j;
for (i = 0; i < pidhashlock + 1; i++) {
+ sx_slock(&proctree_lock);
sx_slock(&pidhashtbl_lock[i]);
for (j = i; j <= pidhash; j += pidhashlock + 1) {
LIST_FOREACH(p, &pidhashtbl[j], p_hash) {
@@ -1662,11 +1663,13 @@ proc_iterate(int (*cb)(struct proc *, void *), void *cbarg)
PROC_LOCK_ASSERT(p, MA_NOTOWNED);
if (error != 0) {
sx_sunlock(&pidhashtbl_lock[i]);
+ sx_sunlock(&proctree_lock);
return (error);
}
}
}
sx_sunlock(&pidhashtbl_lock[i]);
+ sx_sunlock(&proctree_lock);
}
return (0);
}
@@ -1792,9 +1795,11 @@ sysctl_kern_proc(SYSCTL_HANDLER_ARGS)
error = sysctl_wire_old_buffer(req, 0);
if (error)
return (error);
+ sx_slock(&proctree_lock);
error = pget((pid_t)name[0], PGET_CANSEE, &p);
if (error == 0)
error = sysctl_out_proc(p, req, flags);
+ sx_sunlock(&proctree_lock);
return (error);
}