From: Linus Torvalds Date: Sat, 8 Mar 2014 01:38:36 +0000 (-0800) Subject: Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel... X-Git-Url: http://pileus.org/git/?a=commitdiff_plain;h=95648c0e9fdd1cb1199ef387025d684704a8e62e;hp=9579f10dfdd91d5a1bc77a588b630bc945d9fb95;p=~andy%2Flinux Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Peter Anvin: "A small collection of minor fixes. The FPU stuff is still pending, I fear. I haven't heard anything from Suresh so I suspect I'm going to have to dig into the init specifics myself and fix up the patchset" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: Ignore NMIs that come in during early boot x86, trace: Further robustify CR2 handling vs tracing x86, trace: Fix CR2 corruption when tracing page faults x86/efi: Quirk out SGI UV --- diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h index 3d6b9f81cc6..acd86c85041 100644 --- a/arch/x86/include/asm/efi.h +++ b/arch/x86/include/asm/efi.h @@ -134,6 +134,7 @@ extern void efi_setup_page_tables(void); extern void __init old_map_region(efi_memory_desc_t *md); extern void __init runtime_code_page_mkexec(void); extern void __init efi_runtime_mkexec(void); +extern void __init efi_apply_memmap_quirks(void); struct efi_setup_data { u64 fw_vendor; diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S index 81ba27679f1..d2a21590794 100644 --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -544,6 +544,10 @@ ENDPROC(early_idt_handlers) /* This is global to keep gas from relaxing the jumps */ ENTRY(early_idt_handler) cld + + cmpl $X86_TRAP_NMI,(%esp) + je is_nmi # Ignore NMI + cmpl $2,%ss:early_recursion_flag je hlt_loop incl %ss:early_recursion_flag @@ -594,8 +598,9 @@ ex_entry: pop %edx pop %ecx pop %eax - addl $8,%esp /* drop vector number and error code */ decl %ss:early_recursion_flag +is_nmi: + addl $8,%esp /* drop vector number and error code */ iret ENDPROC(early_idt_handler) diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index e1aabdb314c..33f36c78594 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -343,6 +343,9 @@ early_idt_handlers: ENTRY(early_idt_handler) cld + cmpl $X86_TRAP_NMI,(%rsp) + je is_nmi # Ignore NMI + cmpl $2,early_recursion_flag(%rip) jz 1f incl early_recursion_flag(%rip) @@ -405,8 +408,9 @@ ENTRY(early_idt_handler) popq %rdx popq %rcx popq %rax - addq $16,%rsp # drop vector number and error code decl early_recursion_flag(%rip) +is_nmi: + addq $16,%rsp # drop vector number and error code INTERRUPT_RETURN ENDPROC(early_idt_handler) diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 06853e67035..ce72964b2f4 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -1239,14 +1239,8 @@ void __init setup_arch(char **cmdline_p) register_refined_jiffies(CLOCK_TICK_RATE); #ifdef CONFIG_EFI - /* Once setup is done above, unmap the EFI memory map on - * mismatched firmware/kernel archtectures since there is no - * support for runtime services. - */ - if (efi_enabled(EFI_BOOT) && !efi_is_native()) { - pr_info("efi: Setup done, disabling due to 32/64-bit mismatch\n"); - efi_unmap_memmap(); - } + if (efi_enabled(EFI_BOOT)) + efi_apply_memmap_quirks(); #endif } diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 6dea040cc3a..a10c8c79216 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -1020,13 +1020,17 @@ static inline bool smap_violation(int error_code, struct pt_regs *regs) * This routine handles page faults. It determines the address, * and the problem, and then passes it off to one of the appropriate * routines. + * + * This function must have noinline because both callers + * {,trace_}do_page_fault() have notrace on. Having this an actual function + * guarantees there's a function trace entry. */ -static void __kprobes -__do_page_fault(struct pt_regs *regs, unsigned long error_code) +static void __kprobes noinline +__do_page_fault(struct pt_regs *regs, unsigned long error_code, + unsigned long address) { struct vm_area_struct *vma; struct task_struct *tsk; - unsigned long address; struct mm_struct *mm; int fault; unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; @@ -1034,9 +1038,6 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code) tsk = current; mm = tsk->mm; - /* Get the faulting address: */ - address = read_cr2(); - /* * Detect and handle instructions that would cause a page fault for * both a tracked kernel page and a userspace page. @@ -1248,32 +1249,50 @@ good_area: up_read(&mm->mmap_sem); } -dotraplinkage void __kprobes +dotraplinkage void __kprobes notrace do_page_fault(struct pt_regs *regs, unsigned long error_code) { + unsigned long address = read_cr2(); /* Get the faulting address */ enum ctx_state prev_state; + /* + * We must have this function tagged with __kprobes, notrace and call + * read_cr2() before calling anything else. To avoid calling any kind + * of tracing machinery before we've observed the CR2 value. + * + * exception_{enter,exit}() contain all sorts of tracepoints. + */ + prev_state = exception_enter(); - __do_page_fault(regs, error_code); + __do_page_fault(regs, error_code, address); exception_exit(prev_state); } -static void trace_page_fault_entries(struct pt_regs *regs, +#ifdef CONFIG_TRACING +static void trace_page_fault_entries(unsigned long address, struct pt_regs *regs, unsigned long error_code) { if (user_mode(regs)) - trace_page_fault_user(read_cr2(), regs, error_code); + trace_page_fault_user(address, regs, error_code); else - trace_page_fault_kernel(read_cr2(), regs, error_code); + trace_page_fault_kernel(address, regs, error_code); } -dotraplinkage void __kprobes +dotraplinkage void __kprobes notrace trace_do_page_fault(struct pt_regs *regs, unsigned long error_code) { + /* + * The exception_enter and tracepoint processing could + * trigger another page faults (user space callchain + * reading) and destroy the original cr2 value, so read + * the faulting address now. + */ + unsigned long address = read_cr2(); enum ctx_state prev_state; prev_state = exception_enter(); - trace_page_fault_entries(regs, error_code); - __do_page_fault(regs, error_code); + trace_page_fault_entries(address, regs, error_code); + __do_page_fault(regs, error_code, address); exception_exit(prev_state); } +#endif /* CONFIG_TRACING */ diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index 1a201ac7cef..b97acecf3fd 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -52,6 +52,7 @@ #include #include #include +#include #define EFI_DEBUG @@ -1210,3 +1211,22 @@ static int __init parse_efi_cmdline(char *str) return 0; } early_param("efi", parse_efi_cmdline); + +void __init efi_apply_memmap_quirks(void) +{ + /* + * Once setup is done earlier, unmap the EFI memory map on mismatched + * firmware/kernel architectures since there is no support for runtime + * services. + */ + if (!efi_is_native()) { + pr_info("efi: Setup done, disabling due to 32/64-bit mismatch\n"); + efi_unmap_memmap(); + } + + /* + * UV doesn't support the new EFI pagetable mapping yet. + */ + if (is_uv_system()) + set_bit(EFI_OLD_MEMMAP, &x86_efi_facility); +}