Message ID | 20241216164055.96267-15-cgoettsche@seltendoof.de (mailing list archive) |
---|---|
State | Under Review |
Delegated to: | Paul Moore |
Headers | show |
Series | [RFC,v2,01/22] selinux: supply missing field initializers | expand |
On Dec 16, 2024 =?UTF-8?q?Christian=20G=C3=B6ttsche?= <cgoettsche@seltendoof.de> wrote: > > Introduce an ebitmap function to calculate the highest set bit. > > Signed-off-by: Christian Göttsche <cgzones@googlemail.com> > --- > security/selinux/ss/ebitmap.c | 27 +++++++++++++++++++++++++++ > security/selinux/ss/ebitmap.h | 1 + > 2 files changed, 28 insertions(+) > > diff --git a/security/selinux/ss/ebitmap.c b/security/selinux/ss/ebitmap.c > index 43bc19e21960..5d6b5b72b3e5 100644 > --- a/security/selinux/ss/ebitmap.c > +++ b/security/selinux/ss/ebitmap.c > @@ -257,6 +257,33 @@ int ebitmap_contains(const struct ebitmap *e1, const struct ebitmap *e2, > return 1; > } > > +u32 ebitmap_highest_set_bit(const struct ebitmap *e) > +{ > + const struct ebitmap_node *n; > + unsigned long unit; > + u32 pos = 0; > + > + n = e->node; > + if (!n) > + return 0; > + > + while (n->next) > + n = n->next; > + > + for (unsigned int i = EBITMAP_UNIT_NUMS; i > 0; i--) { > + unit = n->maps[i - 1]; > + if (unit == 0) > + continue; > + > + pos = (i - 1) * EBITMAP_UNIT_SIZE; > + while (unit >>= 1) > + pos++; > + break; > + } > + > + return n->startbit + pos; > +} Squash this patch with 16/22. We generally don't add code that isn't used, so squashing this with the caller in 16/22 ensures we have at least one caller. -- paul-moore.com
diff --git a/security/selinux/ss/ebitmap.c b/security/selinux/ss/ebitmap.c index 43bc19e21960..5d6b5b72b3e5 100644 --- a/security/selinux/ss/ebitmap.c +++ b/security/selinux/ss/ebitmap.c @@ -257,6 +257,33 @@ int ebitmap_contains(const struct ebitmap *e1, const struct ebitmap *e2, return 1; } +u32 ebitmap_highest_set_bit(const struct ebitmap *e) +{ + const struct ebitmap_node *n; + unsigned long unit; + u32 pos = 0; + + n = e->node; + if (!n) + return 0; + + while (n->next) + n = n->next; + + for (unsigned int i = EBITMAP_UNIT_NUMS; i > 0; i--) { + unit = n->maps[i - 1]; + if (unit == 0) + continue; + + pos = (i - 1) * EBITMAP_UNIT_SIZE; + while (unit >>= 1) + pos++; + break; + } + + return n->startbit + pos; +} + int ebitmap_get_bit(const struct ebitmap *e, u32 bit) { const struct ebitmap_node *n; diff --git a/security/selinux/ss/ebitmap.h b/security/selinux/ss/ebitmap.h index c9569998f287..12bb359e83ff 100644 --- a/security/selinux/ss/ebitmap.h +++ b/security/selinux/ss/ebitmap.h @@ -126,6 +126,7 @@ int ebitmap_and(struct ebitmap *dst, const struct ebitmap *e1, const struct ebitmap *e2); int ebitmap_contains(const struct ebitmap *e1, const struct ebitmap *e2, u32 last_e2bit); +u32 ebitmap_highest_set_bit(const struct ebitmap *e); int ebitmap_get_bit(const struct ebitmap *e, u32 bit); int ebitmap_set_bit(struct ebitmap *e, u32 bit, int value); void ebitmap_destroy(struct ebitmap *e);