Author: jhb
Date: Tue Jan 18 16:43:01 2011
New Revision: 217543
URL: http://svn.freebsd.org/changeset/base/217543
Log:
- Remove some always-true checks (checking for unsigned < 0).
- Only check largs->num against max_ldt_segment on amd64 for I386_SET_LDT
when descriptors are provided. Specifically, allow the 'start == 0'
and 'num == 0' special case used to free all LDT entries that previously
failed with EINVAL.
Submitted by: clang via rdivacky (some of 1)
Reviewed by: kib
Modified:
head/sys/amd64/amd64/sys_machdep.c
head/sys/i386/i386/sys_machdep.c
Modified: head/sys/amd64/amd64/sys_machdep.c
==============================================================================
--- head/sys/amd64/amd64/sys_machdep.c Tue Jan 18 16:27:40 2011
(r217542)
+++ head/sys/amd64/amd64/sys_machdep.c Tue Jan 18 16:43:01 2011
(r217543)
@@ -95,14 +95,14 @@ sysarch_ldt(struct thread *td, struct sy
largs = &la;
} else
largs = (struct i386_ldt_args *)uap->parms;
- if (largs->num > max_ldt_segment || largs->num <= 0)
- return (EINVAL);
switch (uap->op) {
case I386_GET_LDT:
error = amd64_get_ldt(td, largs);
break;
case I386_SET_LDT:
+ if (largs->descs != NULL && largs->num > max_ldt_segment)
+ return (EINVAL);
set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
if (largs->descs != NULL) {
lp = (struct user_segment_descriptor *)
@@ -539,7 +539,7 @@ amd64_set_ldt(td, uap, descs)
/* Free descriptors */
if (uap->start == 0 && uap->num == 0)
uap->num = max_ldt_segment;
- if (uap->num <= 0)
+ if (uap->num == 0)
return (EINVAL);
if ((pldt = mdp->md_ldt) == NULL ||
uap->start >= max_ldt_segment)
@@ -559,7 +559,7 @@ amd64_set_ldt(td, uap, descs)
/* verify range of descriptors to modify */
largest_ld = uap->start + uap->num;
if (uap->start >= max_ldt_segment ||
- uap->num < 0 || largest_ld > max_ldt_segment)
+ largest_ld > max_ldt_segment)
return (EINVAL);
}
Modified: head/sys/i386/i386/sys_machdep.c
==============================================================================
--- head/sys/i386/i386/sys_machdep.c Tue Jan 18 16:27:40 2011
(r217542)
+++ head/sys/i386/i386/sys_machdep.c Tue Jan 18 16:43:01 2011
(r217543)
@@ -623,7 +623,7 @@ i386_set_ldt(td, uap, descs)
uap->start = NLDT;
uap->num = MAX_LD - NLDT;
}
- if (uap->num <= 0)
+ if (uap->num == 0)
return (EINVAL);
mtx_lock_spin(&dt_lock);
if ((pldt = mdp->md_ldt) == NULL ||
@@ -644,8 +644,7 @@ i386_set_ldt(td, uap, descs)
if (!(uap->start == LDT_AUTO_ALLOC && uap->num == 1)) {
/* verify range of descriptors to modify */
largest_ld = uap->start + uap->num;
- if (uap->start >= MAX_LD ||
- uap->num < 0 || largest_ld > MAX_LD) {
+ if (uap->start >= MAX_LD || largest_ld > MAX_LD) {
return (EINVAL);
}
}
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