[PATCH 2/2] virbpf: Set errno instead of reporting errors

The virbpf module wraps syscalls to BPF. However, if the kernel headers used at the compile time don't have support for BPF the module offers stubs which return a negative one to signal error to the caller. But there is a slight discrepancy between real functions and these stubs. While the former set errno and return -1 the latter report an error (without setting the errno) and return -1. This is not optimal because the caller might see stale errno and overwrite the error message with a less accurate one. Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- po/POTFILES.in | 1 - src/util/virbpf.c | 39 +++++++++++++-------------------------- 2 files changed, 13 insertions(+), 27 deletions(-) diff --git a/po/POTFILES.in b/po/POTFILES.in index 982f2ebc36..8af457aa36 100644 --- a/po/POTFILES.in +++ b/po/POTFILES.in @@ -227,7 +227,6 @@ @SRCDIR(a)/src/util/virauth.c @SRCDIR(a)/src/util/virauthconfig.c @SRCDIR(a)/src/util/virbitmap.c -@SRCDIR(a)/src/util/virbpf.c @SRCDIR(a)/src/util/vircgroup.c @SRCDIR(a)/src/util/vircgroupbackend.c @SRCDIR(a)/src/util/vircgroupbackend.h diff --git a/src/util/virbpf.c b/src/util/virbpf.c index dec8d0133a..987fc34ef4 100644 --- a/src/util/virbpf.c +++ b/src/util/virbpf.c @@ -302,8 +302,7 @@ virBPFCreateMap(unsigned int mapType G_GNUC_UNUSED, unsigned int valSize G_GNUC_UNUSED, unsigned int maxEntries G_GNUC_UNUSED) { - virReportSystemError(ENOSYS, "%s", - _("BPF not supported with this kernel")); + errno = ENOSYS; return -1; } @@ -313,8 +312,7 @@ virBPFLoadProg(struct bpf_insn *insns G_GNUC_UNUSED, int progType G_GNUC_UNUSED, unsigned int insnCnt G_GNUC_UNUSED) { - virReportSystemError(ENOSYS, "%s", - _("BPF not supported with this kernel")); + errno = ENOSYS; return -1; } @@ -324,8 +322,7 @@ virBPFAttachProg(int progfd G_GNUC_UNUSED, int targetfd G_GNUC_UNUSED, int attachType G_GNUC_UNUSED) { - virReportSystemError(ENOSYS, "%s", - _("BPF not supported with this kernel")); + errno = ENOSYS; return -1; } @@ -335,8 +332,7 @@ virBPFDetachProg(int progfd G_GNUC_UNUSED, int targetfd G_GNUC_UNUSED, int attachType G_GNUC_UNUSED) { - virReportSystemError(ENOSYS, "%s", - _("BPF not supported with this kernel")); + errno = ENOSYS; return -1; } @@ -348,8 +344,7 @@ virBPFQueryProg(int targetfd G_GNUC_UNUSED, unsigned int *progcnt G_GNUC_UNUSED, void *progids G_GNUC_UNUSED) { - virReportSystemError(ENOSYS, "%s", - _("BPF not supported with this kernel")); + errno = ENOSYS; return -1; } @@ -357,8 +352,7 @@ virBPFQueryProg(int targetfd G_GNUC_UNUSED, int virBPFGetProg(unsigned int id G_GNUC_UNUSED) { - virReportSystemError(ENOSYS, "%s", - _("BPF not supported with this kernel")); + errno = ENOSYS; return -1; } @@ -368,8 +362,7 @@ virBPFGetProgInfo(int progfd G_GNUC_UNUSED, struct bpf_prog_info *info G_GNUC_UNUSED, unsigned int **mapIDs G_GNUC_UNUSED) { - virReportSystemError(ENOSYS, "%s", - _("BPF not supported with this kernel")); + errno = ENOSYS; return -1; } @@ -377,8 +370,7 @@ virBPFGetProgInfo(int progfd G_GNUC_UNUSED, int virBPFGetMap(unsigned int id G_GNUC_UNUSED) { - virReportSystemError(ENOSYS, "%s", - _("BPF not supported with this kernel")); + errno = ENOSYS; return -1; } @@ -387,8 +379,7 @@ int virBPFGetMapInfo(int mapfd G_GNUC_UNUSED, struct bpf_map_info *info G_GNUC_UNUSED) { - virReportSystemError(ENOSYS, "%s", - _("BPF not supported with this kernel")); + errno = ENOSYS; return -1; } @@ -398,8 +389,7 @@ virBPFLookupElem(int mapfd G_GNUC_UNUSED, void *key G_GNUC_UNUSED, void *val G_GNUC_UNUSED) { - virReportSystemError(ENOSYS, "%s", - _("BPF not supported with this kernel")); + errno = ENOSYS; return -1; } @@ -409,8 +399,7 @@ virBPFGetNextElem(int mapfd G_GNUC_UNUSED, void *key G_GNUC_UNUSED, void *nextKey G_GNUC_UNUSED) { - virReportSystemError(ENOSYS, "%s", - _("BPF not supported with this kernel")); + errno = ENOSYS; return -1; } @@ -420,8 +409,7 @@ virBPFUpdateElem(int mapfd G_GNUC_UNUSED, void *key G_GNUC_UNUSED, void *val G_GNUC_UNUSED) { - virReportSystemError(ENOSYS, "%s", - _("BPF not supported with this kernel")); + errno = ENOSYS; return -1; } @@ -430,8 +418,7 @@ int virBPFDeleteElem(int mapfd G_GNUC_UNUSED, void *key G_GNUC_UNUSED) { - virReportSystemError(ENOSYS, "%s", - _("BPF not supported with this kernel")); + errno = ENOSYS; return -1; } #endif /* !HAVE_SYS_SYSCALL_H || !HAVE_DECL_BPF_PROG_QUERY */ -- 2.24.1