diff options
| -rw-r--r-- | arch/x86/mm/fault.c | 19 | ||||
| -rw-r--r-- | include/linux/mm_types.h | 5 | ||||
| -rw-r--r-- | mm/memory.c | 4 | ||||
| -rw-r--r-- | mm/mempolicy.c | 2 |
4 files changed, 27 insertions, 3 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index e6c469b323cc..8887c6d63ef2 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -37,6 +37,8 @@ #include <asm/irq_stack.h> #include <asm/fred.h> #include <asm/sev.h> /* snp_dump_hva_rmpentry() */ +#include <asm/insn.h> /* struct insn */ +#include <asm/insn-eval.h> /* insn_fetch_from_user(), ... */ #define CREATE_TRACE_POINTS #include <asm/trace/exceptions.h> @@ -1415,6 +1417,23 @@ retry: } mmap_read_unlock(mm); + + if (fault & VM_FAULT_SKIP_INSN) { + u8 buf[MAX_INSN_SIZE]; + struct insn insn; + int nr_copied; + + nr_copied = insn_fetch_from_user(regs, buf); + if (nr_copied <= 0) + return; + + if (!insn_decode_from_regs(&insn, regs, buf, nr_copied)) + return; + + regs->ip += insn.length; + return; + } + done: if (likely(!(fault & VM_FAULT_ERROR))) return; diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 485424979254..a2dda933b09b 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -1249,6 +1249,7 @@ typedef __bitwise unsigned int vm_fault_t; * fsync() to complete (for synchronous page faults * in DAX) * @VM_FAULT_COMPLETED: ->fault completed, meanwhile mmap lock released + * @VM_FAULT_SKIP_INSN: ->handle the fault by skipping faulting instruction * @VM_FAULT_HINDEX_MASK: mask HINDEX value * */ @@ -1266,6 +1267,7 @@ enum vm_fault_reason { VM_FAULT_DONE_COW = (__force vm_fault_t)0x001000, VM_FAULT_NEEDDSYNC = (__force vm_fault_t)0x002000, VM_FAULT_COMPLETED = (__force vm_fault_t)0x004000, + VM_FAULT_SKIP_INSN = (__force vm_fault_t)0x008000, VM_FAULT_HINDEX_MASK = (__force vm_fault_t)0x0f0000, }; @@ -1290,7 +1292,8 @@ enum vm_fault_reason { { VM_FAULT_FALLBACK, "FALLBACK" }, \ { VM_FAULT_DONE_COW, "DONE_COW" }, \ { VM_FAULT_NEEDDSYNC, "NEEDDSYNC" }, \ - { VM_FAULT_COMPLETED, "COMPLETED" } + { VM_FAULT_COMPLETED, "COMPLETED" }, \ + { VM_FAULT_SKIP_INSN, "SKIP_INSN" } struct vm_special_mapping { const char *name; /* The name, e.g. "[vdso]". */ diff --git a/mm/memory.c b/mm/memory.c index 34f8402d2046..405d9c56fa35 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -5841,8 +5841,10 @@ vm_fault_t handle_mm_fault(struct vm_area_struct *vma, unsigned long address, lru_gen_exit_fault(); /* If the mapping is droppable, then errors due to OOM aren't fatal. */ - if (is_droppable) + if (is_droppable && (ret & VM_FAULT_OOM)) { ret &= ~VM_FAULT_OOM; + ret |= VM_FAULT_SKIP_INSN; + } if (flags & FAULT_FLAG_USER) { mem_cgroup_exit_user_fault(); diff --git a/mm/mempolicy.c b/mm/mempolicy.c index b858e22b259d..d75e0ee19aa3 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -2306,7 +2306,7 @@ struct folio *vma_alloc_folio_noprof(gfp_t gfp, int order, struct vm_area_struct struct folio *folio; if (vma->vm_flags & VM_DROPPABLE) - gfp |= __GFP_NOWARN; + gfp |= __GFP_NOWARN | __GFP_NORETRY; pol = get_vma_policy(vma, addr, order, &ilx); folio = folio_alloc_mpol_noprof(gfp, order, pol, ilx, numa_node_id()); |