diff options
| author | Tony Luck <tony.luck@intel.com> | 2005-10-20 10:41:44 -0700 |
|---|---|---|
| committer | Tony Luck <tony.luck@intel.com> | 2005-10-20 10:41:44 -0700 |
| commit | 9cec58dc138d6fcad9f447a19c8ff69f6540e667 (patch) | |
| tree | 4fe1cca94fdba8b705c87615bee06d3346f687ce /arch/arm/mm/fault.c | |
| parent | 17e5ad6c0ce5a970e2830d0de8bdd60a2f077d38 (diff) | |
| parent | ac9b9c667c2e1194e22ebe0a441ae1c37aaa9b90 (diff) | |
Update from upstream with manual merge of Yasunori Goto's
changes to swiotlb.c made in commit 281dd25cdc0d6903929b79183816d151ea626341
since this file has been moved from arch/ia64/lib/swiotlb.c to
lib/swiotlb.c
Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'arch/arm/mm/fault.c')
| -rw-r--r-- | arch/arm/mm/fault.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index 0b6c4db44e0..4a884baf3b9 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -233,7 +233,17 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) if (in_interrupt() || !mm) goto no_context; - down_read(&mm->mmap_sem); + /* + * As per x86, we may deadlock here. However, since the kernel only + * validly references user space from well defined areas of the code, + * we can bug out early if this is from code which shouldn't. + */ + if (!down_read_trylock(&mm->mmap_sem)) { + if (!user_mode(regs) && !search_exception_tables(regs->ARM_pc)) + goto no_context; + down_read(&mm->mmap_sem); + } + fault = __do_page_fault(mm, addr, fsr, tsk); up_read(&mm->mmap_sem); |