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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/powerpc/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/powerpc/mm/fault.c')
| -rw-r--r-- | arch/powerpc/mm/fault.c | 23 |
1 files changed, 11 insertions, 12 deletions
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index 2393ed9d84bb..641fc5f3d7dd 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -35,7 +35,6 @@ #include <asm/firmware.h> #include <asm/page.h> -#include <asm/pgtable.h> #include <asm/mmu.h> #include <asm/mmu_context.h> #include <asm/siginfo.h> @@ -109,7 +108,7 @@ static int __bad_area(struct pt_regs *regs, unsigned long address, int si_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); return __bad_area_nosemaphore(regs, address, si_code); } @@ -139,13 +138,13 @@ static noinline int bad_access_pkey(struct pt_regs *regs, unsigned long address, * 2. T1 : set AMR 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. */ pkey = vma_pkey(vma); - up_read(&mm->mmap_sem); + mmap_read_unlock(mm); /* * If we are in kernel mode, bail out with a SEGV, this will @@ -526,9 +525,9 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address, perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); /* - * We want to do this outside mmap_sem, because reading code around nip + * We want to do this outside mmap_lock, because reading code around nip * can result in fault, which will cause a deadlock when called with - * mmap_sem held + * mmap_lock held */ if (is_user) flags |= FAULT_FLAG_USER; @@ -540,7 +539,7 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address, /* When running in the kernel we expect faults to occur only to * addresses in user space. All other faults represent errors in the * kernel and should generate an OOPS. Unfortunately, in the case of an - * erroneous fault occurring in a code path which already holds mmap_sem + * erroneous fault occurring in a code path which already holds mmap_lock * we will deadlock attempting to validate the fault against the * address space. Luckily the kernel only validly references user * space from well defined areas of code, which are listed in the @@ -552,12 +551,12 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address, * source. If this is invalid we can skip the address space check, * thus avoiding the deadlock. */ - if (unlikely(!down_read_trylock(&mm->mmap_sem))) { + if (unlikely(!mmap_read_trylock(mm))) { if (!is_user && !search_exception_tables(regs->nip)) return bad_area_nosemaphore(regs, address); retry: - down_read(&mm->mmap_sem); + mmap_read_lock(mm); } else { /* * The above down_read_trylock() might have succeeded in @@ -581,7 +580,7 @@ retry: if (!must_retry) return bad_area(regs, address); - up_read(&mm->mmap_sem); + mmap_read_unlock(mm); if (fault_in_pages_readable((const char __user *)regs->nip, sizeof(unsigned int))) return bad_area_nosemaphore(regs, address); @@ -616,7 +615,7 @@ good_area: return user_mode(regs) ? 0 : SIGBUS; /* - * Handle the retry right now, the mmap_sem has been released in that + * Handle the retry right now, the mmap_lock has been released in that * case. */ if (unlikely(fault & VM_FAULT_RETRY)) { @@ -626,7 +625,7 @@ good_area: } } - up_read(¤t->mm->mmap_sem); + mmap_read_unlock(current->mm); if (unlikely(fault & VM_FAULT_ERROR)) return mm_fault_error(regs, address, fault); |