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| author | dillon <dillon@FreeBSD.org> | 1999-09-20 19:08:48 +0000 |
|---|---|---|
| committer | dillon <dillon@FreeBSD.org> | 1999-09-20 19:08:48 +0000 |
| commit | e8761b4e052785153d92b664a5dbe32e4a1de18e (patch) | |
| tree | dcac6780728b4221aa67e14342e5541829c1b0c5 /sys/kern/sys_pipe.c | |
| parent | 93e77b056762475c3c25ed8a6e2f428c8969b448 (diff) | |
| download | FreeBSD-src-e8761b4e052785153d92b664a5dbe32e4a1de18e.zip FreeBSD-src-e8761b4e052785153d92b664a5dbe32e4a1de18e.tar.gz | |
Fix bug in pipe code relating to writes of mmap'd but illegal address
spaces which cross a segment boundry in the page table. pmap_kextract()
is not designed for access to the user space portion of the page
table and cannot handle the null-page-directory-entry case.
The fix is to have vm_fault_quick() return a success or failure which
is then used to avoid calling pmap_kextract().
Diffstat (limited to 'sys/kern/sys_pipe.c')
| -rw-r--r-- | sys/kern/sys_pipe.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/sys/kern/sys_pipe.c b/sys/kern/sys_pipe.c index c8f8e35..ee883ed 100644 --- a/sys/kern/sys_pipe.c +++ b/sys/kern/sys_pipe.c @@ -490,9 +490,8 @@ pipe_build_write_buffer(wpipe, uio) vm_page_t m; - vm_fault_quick( (caddr_t) addr, VM_PROT_READ); - paddr = pmap_kextract(addr); - if (!paddr) { + if (vm_fault_quick((caddr_t)addr, VM_PROT_READ) < 0 || + (paddr = pmap_kextract(addr)) == 0) { int j; for(j=0;j<i;j++) vm_page_unwire(wpipe->pipe_map.ms[j], 1); |
