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| author | ngie <ngie@FreeBSD.org> | 2017-03-28 06:05:26 +0000 |
|---|---|---|
| committer | ngie <ngie@FreeBSD.org> | 2017-03-28 06:05:26 +0000 |
| commit | 36550dd2e20ed117f797918355be27e85e62fd49 (patch) | |
| tree | 396d36f084ac882eb6cb2f99cf3c9c8ec3bed8f5 | |
| parent | 8832cc10cf95a896d6fb7d0054fbb5f6f0d154cd (diff) | |
| download | FreeBSD-src-36550dd2e20ed117f797918355be27e85e62fd49.zip FreeBSD-src-36550dd2e20ed117f797918355be27e85e62fd49.tar.gz | |
MFC r315686,r315688:
r315686:
kvm_geterr: handle `kd` == NULL in a deterministic/graceful manner
Return a NUL string instead of just working by accident with kvm_geterr(3)
when MALLOC_PRODUCTION is disabled (I didn't confirm the MALLOC_PRODUCTION
being enabled path).
Document the new explicit return behavior for kvm_geterr(3), as well
as the previous implicit behavior, i.e., the buffer attached to
returned via kvm_geterr(3) would be empty if a previous error hadn't been
stored in `kd`.
r315688:
kvm_write: fix -Wcast-qual warning in pointer arithmetic argument
Cast buf to `const char *` when doing arithmetic operation to match
`cp`'s type [1].
| -rw-r--r-- | lib/libkvm/kvm.c | 7 | ||||
| -rw-r--r-- | lib/libkvm/kvm_geterr.3 | 11 |
2 files changed, 16 insertions, 2 deletions
diff --git a/lib/libkvm/kvm.c b/lib/libkvm/kvm.c index b814e8c..e731a29 100644 --- a/lib/libkvm/kvm.c +++ b/lib/libkvm/kvm.c @@ -76,9 +76,14 @@ static char sccsid[] = "@(#)kvm.c 8.2 (Berkeley) 2/13/94"; /* from src/lib/libc/gen/nlist.c */ int __fdnlist(int, struct nlist *); +static char _kd_is_null[] = ""; + char * kvm_geterr(kvm_t *kd) { + + if (kd == NULL) + return (_kd_is_null); return (kd->errbuf); } @@ -623,5 +628,5 @@ kvm_write(kvm_t *kd, u_long kva, const void *buf, size_t len) len -= cw; } - return (cp - (char *)buf); + return (cp - (const char *)buf); } diff --git a/lib/libkvm/kvm_geterr.3 b/lib/libkvm/kvm_geterr.3 index 3ce5c72..4aa9cc8 100644 --- a/lib/libkvm/kvm_geterr.3 +++ b/lib/libkvm/kvm_geterr.3 @@ -32,7 +32,7 @@ .\" @(#)kvm_geterr.3 8.1 (Berkeley) 6/4/93 .\" $FreeBSD$ .\" -.Dd June 4, 1993 +.Dd March 21, 2017 .Dt KVM_GETERR 3 .Os .Sh NAME @@ -54,6 +54,15 @@ library call did not produce an error. The string returned is stored in memory owned by .Xr kvm 3 so the message should be copied out and saved elsewhere if necessary. +.Sh RETURN VALUES +The function +.Fn kvm_geterr +will return "" if +.Fa kd +is +.Dv NULL +or an error has not been captured for +.Fa kd . .Sh SEE ALSO .Xr kvm 3 , .Xr kvm_close 3 , |
