Author: alc
Date: Mon Jun 4 16:28:06 2018
New Revision: 334621
URL: https://svnweb.freebsd.org/changeset/base/334621
Log:
Use a single, consistent approach to returning success versus failure in
vm_map_madvise(). Previously, vm_map_madvise() used a traditional Unix-
style "return (0);" to indicate success in the common case, but Mach-
style return values in the edge cases. Since KERN_SUCCESS equals zero,
the only problem with this inconsistency was stylistic. vm_map_madvise()
has exactly two callers in the entire source tree, and only one of them
cares about the return value. That caller, kern_madvise(), can be
simplified if vm_map_madvise() consistently uses Unix-style return
values.
Since vm_map_madvise() uses the variable modify_map as a Boolean, make it
one.
Eliminate a redundant error check from kern_madvise(). Add a comment
explaining where the check is performed.
Explicitly note that exec_release_args_kva() doesn't care about
vm_map_madvise()'s return value. Since MADV_FREE is passed as the
behavior, the return value will always be zero.
Reviewed by: kib, markj
MFC after: 7 days
Modified:
head/sys/kern/kern_exec.c
head/sys/vm/vm_map.c
head/sys/vm/vm_mmap.c
Modified: head/sys/kern/kern_exec.c
==============================================================================
--- head/sys/kern/kern_exec.c Mon Jun 4 16:21:18 2018 (r334620)
+++ head/sys/kern/kern_exec.c Mon Jun 4 16:28:06 2018 (r334621)
@@ -1380,7 +1380,7 @@ exec_release_args_kva(struct exec_args_kva *argkva, u_
base = argkva->addr;
if (argkva->gen != gen) {
- vm_map_madvise(exec_map, base, base + exec_map_entry_size,
+ (void)vm_map_madvise(exec_map, base, base + exec_map_entry_size,
MADV_FREE);
argkva->gen = gen;
}
Modified: head/sys/vm/vm_map.c
==============================================================================
--- head/sys/vm/vm_map.c Mon Jun 4 16:21:18 2018 (r334620)
+++ head/sys/vm/vm_map.c Mon Jun 4 16:28:06 2018 (r334621)
@@ -2215,7 +2215,7 @@ vm_map_madvise(
int behav)
{
vm_map_entry_t current, entry;
- int modify_map = 0;
+ bool modify_map;
/*
* Some madvise calls directly modify the vm_map_entry, in which case
@@ -2232,19 +2232,20 @@ vm_map_madvise(
case MADV_NOCORE:
case MADV_CORE:
if (start == end)
- return (KERN_SUCCESS);
- modify_map = 1;
+ return (0);
+ modify_map = true;
vm_map_lock(map);
break;
case MADV_WILLNEED:
case MADV_DONTNEED:
case MADV_FREE:
if (start == end)
- return (KERN_SUCCESS);
+ return (0);
+ modify_map = false;
vm_map_lock_read(map);
break;
default:
- return (KERN_INVALID_ARGUMENT);
+ return (EINVAL);
}
/*
Modified: head/sys/vm/vm_mmap.c
==============================================================================
--- head/sys/vm/vm_mmap.c Mon Jun 4 16:21:18 2018 (r334620)
+++ head/sys/vm/vm_mmap.c Mon Jun 4 16:28:06 2018 (r334621)
@@ -683,11 +683,6 @@ kern_madvise(struct thread *td, uintptr_t addr0, size_
}
/*
- * Check for illegal behavior
- */
- if (behav < 0 || behav > MADV_CORE)
- return (EINVAL);
- /*
* Check for illegal addresses. Watch out for address wrap... Note
* that VM_*_ADDRESS are not constants due to casts (argh).
*/
@@ -705,9 +700,10 @@ kern_madvise(struct thread *td, uintptr_t addr0, size_
start = trunc_page(addr);
end = round_page(addr + len);
- if (vm_map_madvise(map, start, end, behav))
- return (EINVAL);
- return (0);
+ /*
+ * vm_map_madvise() checks for illegal values of behav.
+ */
+ return (vm_map_madvise(map, start, end, behav));
}
#ifndef _SYS_SYSPROTO_H_
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