diff options
| author | dillon <dillon@FreeBSD.org> | 2000-02-16 21:11:33 +0000 |
|---|---|---|
| committer | dillon <dillon@FreeBSD.org> | 2000-02-16 21:11:33 +0000 |
| commit | 7a2987cf9410d129917e89db27af78911bd0fb60 (patch) | |
| tree | e9fa93a9df696f57e919e1e8f97b841d07227b0b /lib/libc | |
| parent | e8cfdc976f1f31ae86f30a656797e2820c9f439b (diff) | |
| download | FreeBSD-src-7a2987cf9410d129917e89db27af78911bd0fb60.zip FreeBSD-src-7a2987cf9410d129917e89db27af78911bd0fb60.tar.gz | |
Fix null-pointer dereference crash when the system is intentionally
run out of KVM through a mmap()/fork() bomb that allocates hundreds
of thousands of vm_map_entry structures.
Add panic to make null-pointer dereference crash a little more verbose.
Add a new sysctl, vm.max_proc_mmap, which specifies the maximum number
of mmap()'d spaces (discrete vm_map_entry's in the process). The value
defaults to around 9000 for a 128MB machine. The test is scaled for the
number of processes sharing a vmspace (aka linux threads). Setting
the value to 0 disables the feature.
PR: kern/16573
Approved by: jkh
Diffstat (limited to 'lib/libc')
| -rw-r--r-- | lib/libc/sys/mmap.2 | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/lib/libc/sys/mmap.2 b/lib/libc/sys/mmap.2 index 1906e53..433f8b7 100644 --- a/lib/libc/sys/mmap.2 +++ b/lib/libc/sys/mmap.2 @@ -253,7 +253,8 @@ was not page-aligned. (See BUGS below.) .Dv MAP_FIXED was specified and the .Fa addr -parameter wasn't available. +parameter wasn't available, or the system has reached the per-process mmap +limit specified in the vm.max_proc_mmap sysctl. .Dv MAP_ANON was specified and insufficient memory was available. .Sh "SEE ALSO" |
