diff options
| author | Suren Baghdasaryan <surenb@google.com> | 2023-02-27 20:36:28 +0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-04-06 06:03:01 +0300 |
| commit | 0bff0aaea03e2a3ed6bfa302155cca8a432a1829 (patch) | |
| tree | d686c2cd745e2a8ed09c59031f1d1e27cdb806bf /arch/x86/mm/fault.c | |
| parent | 52f238653e452e0fda61e880f263a173d219acd1 (diff) | |
| download | linux-0bff0aaea03e2a3ed6bfa302155cca8a432a1829.tar.xz | |
x86/mm: try VMA lock-based page fault handling first
Attempt VMA lock-based page fault handling first, and fall back to the
existing mmap_lock-based handling if that fails.
Link: https://lkml.kernel.org/r/20230227173632.3292573-30-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'arch/x86/mm/fault.c')
| -rw-r--r-- | arch/x86/mm/fault.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index a498ae1fbe66..e4399983c50c 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -19,6 +19,7 @@ #include <linux/uaccess.h> /* faulthandler_disabled() */ #include <linux/efi.h> /* efi_crash_gracefully_on_page_fault()*/ #include <linux/mm_types.h> +#include <linux/mm.h> /* find_and_lock_vma() */ #include <asm/cpufeature.h> /* boot_cpu_has, ... */ #include <asm/traps.h> /* dotraplinkage, ... */ @@ -1333,6 +1334,38 @@ void do_user_addr_fault(struct pt_regs *regs, } #endif +#ifdef CONFIG_PER_VMA_LOCK + if (!(flags & FAULT_FLAG_USER)) + goto lock_mmap; + + vma = lock_vma_under_rcu(mm, address); + if (!vma) + goto lock_mmap; + + if (unlikely(access_error(error_code, vma))) { + vma_end_read(vma); + goto lock_mmap; + } + fault = handle_mm_fault(vma, address, flags | FAULT_FLAG_VMA_LOCK, regs); + vma_end_read(vma); + + if (!(fault & VM_FAULT_RETRY)) { + count_vm_vma_lock_event(VMA_LOCK_SUCCESS); + goto done; + } + count_vm_vma_lock_event(VMA_LOCK_RETRY); + + /* Quick path to respond to signals */ + if (fault_signal_pending(fault, regs)) { + if (!user_mode(regs)) + kernelmode_fixup_or_oops(regs, error_code, address, + SIGBUS, BUS_ADRERR, + ARCH_DEFAULT_PKEY); + return; + } +lock_mmap: +#endif /* CONFIG_PER_VMA_LOCK */ + /* * Kernel-mode access to the user address space should only occur * on well-defined single instructions listed in the exception @@ -1433,6 +1466,9 @@ good_area: } mmap_read_unlock(mm); +#ifdef CONFIG_PER_VMA_LOCK +done: +#endif if (likely(!(fault & VM_FAULT_ERROR))) return; |