Date: Sun, 26 Oct 2014 12:08:19 +0800 From: Tiwei Bie <btw@mail.ustc.edu.cn> To: mjg@freebsd.org Cc: freebsd-hackers@freebsd.org Subject: [PATCH] Finish the task 'Temporary buffer in setgroups' Message-ID: <1414296499-55792-1-git-send-email-btw@mail.ustc.edu.cn>
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Hi, mjg!
I have finished the task: Temporary buffer in setgroups [1].
Following is my patch:
diff --git a/sys/kern/kern_prot.c b/sys/kern/kern_prot.c
index f12468d..73f6ab7 100644
--- a/sys/kern/kern_prot.c
+++ b/sys/kern/kern_prot.c
@@ -806,17 +806,24 @@ int
sys_setgroups(struct thread *td, struct setgroups_args *uap)
{
gid_t *groups = NULL;
+ gid_t smallgroups[XU_NGROUPS];
+ u_int gidsetsize;
int error;
- if (uap->gidsetsize > ngroups_max + 1)
+ gidsetsize = uap->gidsetsize;
+ if (gidsetsize > ngroups_max + 1)
return (EINVAL);
- groups = malloc(uap->gidsetsize * sizeof(gid_t), M_TEMP, M_WAITOK);
- error = copyin(uap->gidset, groups, uap->gidsetsize * sizeof(gid_t));
+ if (gidsetsize > XU_NGROUPS)
+ groups = malloc(gidsetsize * sizeof(gid_t), M_TEMP, M_WAITOK);
+ else
+ groups = smallgroups;
+ error = copyin(uap->gidset, groups, gidsetsize * sizeof(gid_t));
if (error)
goto out;
- error = kern_setgroups(td, uap->gidsetsize, groups);
+ error = kern_setgroups(td, gidsetsize, groups);
out:
- free(groups, M_TEMP);
+ if (gidsetsize > XU_NGROUPS)
+ free(groups, M_TEMP);
return (error);
}
--
2.1.0
[1] https://wiki.freebsd.org/JuniorJobs#Temporary_buffer_in_setgroups
Tiwei Bie
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