diff options
author | Jeff Garzik <jgarzik@pobox.com> | 2005-10-06 05:51:07 -0400 |
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committer | Jeff Garzik <jgarzik@pobox.com> | 2005-10-06 05:51:07 -0400 |
commit | 012e060c95e547eceea4a12c6f58592473bf4011 (patch) | |
tree | b57d3eafb50ce517577d2cf366c9ef0b4b286589 /arch/arm/mm/fault.c | |
parent | 923f122573851d18a3832ca808269fa2d5046fb1 (diff) | |
parent | ed39f731ab2e77e58122232f6e27333331d7793d (diff) |
Merge branch 'master'
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); |