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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-09 09:54:46 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-09 09:54:46 -0700 |
| commit | a5ad5742f671de906adbf29fbedf0a04705cebad (patch) | |
| tree | 88d1a4c18e2025a5a8335dbbc9dea8bebeba5789 /arch/x86/mm/fault.c | |
| parent | 013b2deba9a6b80ca02f4fafd7dedf875e9b4450 (diff) | |
| parent | 4fa7252338a56fbc90220e6330f136a379175a7a (diff) | |
| download | lwn-a5ad5742f671de906adbf29fbedf0a04705cebad.tar.gz lwn-a5ad5742f671de906adbf29fbedf0a04705cebad.zip | |
Merge branch 'akpm' (patches from Andrew)
Merge even more updates from Andrew Morton:
- a kernel-wide sweep of show_stack()
- pagetable cleanups
- abstract out accesses to mmap_sem - prep for mmap_sem scalability work
- hch's user acess work
Subsystems affected by this patch series: debug, mm/pagemap, mm/maccess,
mm/documentation.
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (93 commits)
include/linux/cache.h: expand documentation over __read_mostly
maccess: return -ERANGE when probe_kernel_read() fails
x86: use non-set_fs based maccess routines
maccess: allow architectures to provide kernel probing directly
maccess: move user access routines together
maccess: always use strict semantics for probe_kernel_read
maccess: remove strncpy_from_unsafe
tracing/kprobes: handle mixed kernel/userspace probes better
bpf: rework the compat kernel probe handling
bpf:bpf_seq_printf(): handle potentially unsafe format string better
bpf: handle the compat string in bpf_trace_copy_string better
bpf: factor out a bpf_trace_copy_string helper
maccess: unify the probe kernel arch hooks
maccess: remove probe_read_common and probe_write_common
maccess: rename strnlen_unsafe_user to strnlen_user_nofault
maccess: rename strncpy_from_unsafe_strict to strncpy_from_kernel_nofault
maccess: rename strncpy_from_unsafe_user to strncpy_from_user_nofault
maccess: update the top of file comment
maccess: clarify kerneldoc comments
maccess: remove duplicate kerneldoc comments
...
Diffstat (limited to 'arch/x86/mm/fault.c')
| -rw-r--r-- | arch/x86/mm/fault.c | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index c5437f2964ee..0b03ae8c39cd 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -811,7 +811,7 @@ __bad_area(struct pt_regs *regs, unsigned long error_code, * Something tried to access memory that isn't in our memory map.. * Fix it, but check if it's kernel or user first.. */ - up_read(&mm->mmap_sem); + mmap_read_unlock(mm); __bad_area_nosemaphore(regs, error_code, address, pkey, si_code); } @@ -865,7 +865,7 @@ bad_area_access_error(struct pt_regs *regs, unsigned long error_code, * 2. T1 : set PKRU to deny access to pkey=4, touches page * 3. T1 : faults... * 4. T2: mprotect_key(foo, PAGE_SIZE, pkey=5); - * 5. T1 : enters fault handler, takes mmap_sem, etc... + * 5. T1 : enters fault handler, takes mmap_lock, etc... * 6. T1 : reaches here, sees vma_pkey(vma)=5, when we really * faulted on a pte with its pkey=4. */ @@ -1231,15 +1231,15 @@ void do_user_addr_fault(struct pt_regs *regs, * Kernel-mode access to the user address space should only occur * on well-defined single instructions listed in the exception * tables. But, an erroneous kernel fault occurring outside one of - * those areas which also holds mmap_sem might deadlock attempting + * those areas which also holds mmap_lock might deadlock attempting * to validate the fault against the address space. * * Only do the expensive exception table search when we might be at * risk of a deadlock. This happens if we - * 1. Failed to acquire mmap_sem, and + * 1. Failed to acquire mmap_lock, and * 2. The access did not originate in userspace. */ - if (unlikely(!down_read_trylock(&mm->mmap_sem))) { + if (unlikely(!mmap_read_trylock(mm))) { if (!user_mode(regs) && !search_exception_tables(regs->ip)) { /* * Fault from code in kernel from @@ -1249,7 +1249,7 @@ void do_user_addr_fault(struct pt_regs *regs, return; } retry: - down_read(&mm->mmap_sem); + mmap_read_lock(mm); } else { /* * The above down_read_trylock() might have succeeded in @@ -1289,9 +1289,9 @@ good_area: * If for any reason at all we couldn't handle the fault, * make sure we exit gracefully rather than endlessly redo * the fault. Since we never set FAULT_FLAG_RETRY_NOWAIT, if - * we get VM_FAULT_RETRY back, the mmap_sem has been unlocked. + * we get VM_FAULT_RETRY back, the mmap_lock has been unlocked. * - * Note that handle_userfault() may also release and reacquire mmap_sem + * Note that handle_userfault() may also release and reacquire mmap_lock * (and not return with VM_FAULT_RETRY), when returning to userland to * repeat the page fault later with a VM_FAULT_NOPAGE retval * (potentially after handling any pending signal during the return to @@ -1310,7 +1310,7 @@ good_area: } /* - * If we need to retry the mmap_sem has already been released, + * If we need to retry the mmap_lock has already been released, * and if there is a fatal signal pending there is no guarantee * that we made any progress. Handle this case first. */ @@ -1320,7 +1320,7 @@ good_area: goto retry; } - up_read(&mm->mmap_sem); + mmap_read_unlock(mm); if (unlikely(fault & VM_FAULT_ERROR)) { mm_fault_error(regs, hw_error_code, address, fault); return; @@ -1359,7 +1359,7 @@ dotraplinkage void do_page_fault(struct pt_regs *regs, unsigned long hw_error_code, unsigned long address) { - prefetchw(¤t->mm->mmap_sem); + prefetchw(¤t->mm->mmap_lock); /* * KVM has two types of events that are, logically, interrupts, but * are unfortunately delivered using the #PF vector. These events are |