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author | Michał Górny <mgorny@gentoo.org> | 2021-11-07 21:11:52 +0000 |
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committer | John Baldwin <jhb@FreeBSD.org> | 2021-12-07 23:36:34 +0000 |
commit | 8099a354469a012512d9850302edaa0e27c75fd7 (patch) | |
tree | 20c48fc7b6311d47e4df38a63cde27a8130ede5d | |
parent | e9aeb50797fcaab1829ea626c1efd75de203a410 (diff) | |
download | src-8099a354469a012512d9850302edaa0e27c75fd7.tar.gz src-8099a354469a012512d9850302edaa0e27c75fd7.zip |
libkvm: Fix kvm_getloadavg() on modern kernel vmcores
Fix kvm_getloadavg() to work correctly on vmcores for modern kernel
versions. The kernels no longer include the `_fscale` symbol causing
the kvm_nlist() invocation to fail. The code seemed to already assume
that `_fscale` could be missing but the early kvm_nlist() result check
has caused the function to fail if any symbol were missing. Modify
it to only treat `_averunnable` as obligatory, and handle missing
`_fscale` gracefully.
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D32884
-rw-r--r-- | lib/libkvm/kvm_getloadavg.c | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/lib/libkvm/kvm_getloadavg.c b/lib/libkvm/kvm_getloadavg.c index 0f2a5f69bcf0..f94b1d844663 100644 --- a/lib/libkvm/kvm_getloadavg.c +++ b/lib/libkvm/kvm_getloadavg.c @@ -62,7 +62,6 @@ int kvm_getloadavg(kvm_t *kd, double loadavg[], int nelem) { struct loadavg loadinfo; - struct nlist *p; int fscale, i; if (ISALIVE(kd)) @@ -74,10 +73,9 @@ kvm_getloadavg(kvm_t *kd, double loadavg[], int nelem) return (-1); } - if (kvm_nlist(kd, nl) != 0) { - for (p = nl; p->n_type != 0; ++p); + if (kvm_nlist(kd, nl) != 0 && nl[X_AVERUNNABLE].n_type == 0) { _kvm_err(kd, kd->program, - "%s: no such symbol", p->n_name); + "%s: no such symbol", nl[X_AVERUNNABLE].n_name); return (-1); } @@ -92,7 +90,8 @@ kvm_getloadavg(kvm_t *kd, double loadavg[], int nelem) * Old kernels have fscale separately; if not found assume * running new format. */ - if (!KREAD(kd, nl[X_FSCALE].n_value, &fscale)) + if (nl[X_FSCALE].n_type != 0 && + !KREAD(kd, nl[X_FSCALE].n_value, &fscale)) loadinfo.fscale = fscale; nelem = MIN(nelem, (int)(sizeof(loadinfo.ldavg) / sizeof(fixpt_t))); |