diff options
Diffstat (limited to 'arch/x86/mm/fault.c')
| -rw-r--r-- | arch/x86/mm/fault.c | 32 |
1 files changed, 18 insertions, 14 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 8224567abdb6..402e08f6b7ec 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -34,6 +34,7 @@ #include <asm/kvm_para.h> /* kvm_handle_async_pf */ #include <asm/vdso.h> /* fixup_vdso_exception() */ #include <asm/irq_stack.h> +#include <asm/fred.h> #include <asm/sev.h> /* snp_dump_hva_rmpentry() */ #define CREATE_TRACE_POINTS @@ -1298,21 +1299,14 @@ void do_user_addr_fault(struct pt_regs *regs, return; } - /* - * It's safe to allow irq's after cr2 has been saved and the - * vmalloc fault has been handled. - * - * User-mode registers count as a user access even for any - * potential system fault or CPU buglet: - */ - if (user_mode(regs)) { - local_irq_enable(); - flags |= FAULT_FLAG_USER; - } else { - if (regs->flags & X86_EFLAGS_IF) - local_irq_enable(); + /* Legacy check - remove this after verifying that it doesn't trigger */ + if (WARN_ON_ONCE(!(regs->flags & X86_EFLAGS_IF))) { + bad_area_nosemaphore(regs, error_code, address); + return; } + local_irq_enable(); + perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); /* @@ -1328,6 +1322,14 @@ void do_user_addr_fault(struct pt_regs *regs, if (error_code & X86_PF_INSTR) flags |= FAULT_FLAG_INSTRUCTION; + /* + * We set FAULT_FLAG_USER based on the register state, not + * based on X86_PF_USER. User space accesses that cause + * system page faults are still user accesses. + */ + if (user_mode(regs)) + flags |= FAULT_FLAG_USER; + #ifdef CONFIG_X86_64 /* * Faults in the vsyscall page might need emulation. The @@ -1514,8 +1516,10 @@ handle_page_fault(struct pt_regs *regs, unsigned long error_code, DEFINE_IDTENTRY_RAW_ERRORCODE(exc_page_fault) { - unsigned long address = read_cr2(); irqentry_state_t state; + unsigned long address; + + address = cpu_feature_enabled(X86_FEATURE_FRED) ? fred_event_data(regs) : read_cr2(); prefetchw(¤t->mm->mmap_lock); |