Commit fdfe8aa8 authored by Harvey Harrison's avatar Harvey Harrison Committed by Ingo Molnar
Browse files

x86: function ifdefs in fault_32|64.c 



Add caller of is_errata93() to X86_32, ifdef'd to do
nothing.

Signed-off-by: default avatarHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 6f4d368e

arch/x86/mm/fault_32.c

+56 −3
Original line number Diff line number Diff line
@@ -217,6 +217,7 @@ KERN_ERR "******* Your BIOS seems to not contain a fix for K8 errata #93\n" 
KERN_ERR "******* Working around it, but it may cause SEGVs or burn power.\n"

KERN_ERR "******* Please consider a BIOS update.\n"

KERN_ERR "******* Disabling USB legacy in the BIOS may also help.\n";

#endif



/* Workaround for K8 erratum #93 & buggy BIOS.

   BIOS SMM functions are required to use a specific workaround
@@ -224,10 +225,12 @@ KERN_ERR "******* Disabling USB legacy in the BIOS may also help.\n"; 
   A lot of BIOS that didn't get tested properly miss this.

   The OS sees this as a page fault with the upper 32bits of RIP cleared.

   Try to work around it here.

   Note we only handle faults in kernel here. */



   Note we only handle faults in kernel here.

   Does nothing for X86_32

 */

static int is_errata93(struct pt_regs *regs, unsigned long address)

{

#ifdef CONFIG_X86_64

	static int warned;

	if (address != regs->ip)

		return 0;
@@ -243,9 +246,10 @@ static int is_errata93(struct pt_regs *regs, unsigned long address) 
		regs->ip = address;

		return 1;

	}

#endif

	return 0;

}

#endif





/*

 * Handle a fault on the vmalloc or module mapping area
@@ -254,6 +258,7 @@ static int is_errata93(struct pt_regs *regs, unsigned long address) 
 */

static inline int vmalloc_fault(unsigned long address)

{

#ifdef CONFIG_X86_32

	unsigned long pgd_paddr;

	pmd_t *pmd_k;

	pte_t *pte_k;
@@ -272,6 +277,51 @@ static inline int vmalloc_fault(unsigned long address) 
	if (!pte_present(*pte_k))

		return -1;

	return 0;

#else

	pgd_t *pgd, *pgd_ref;

	pud_t *pud, *pud_ref;

	pmd_t *pmd, *pmd_ref;

	pte_t *pte, *pte_ref;



	/* Copy kernel mappings over when needed. This can also

	   happen within a race in page table update. In the later

	   case just flush. */



	pgd = pgd_offset(current->mm ?: &init_mm, address);

	pgd_ref = pgd_offset_k(address);

	if (pgd_none(*pgd_ref))

		return -1;

	if (pgd_none(*pgd))

		set_pgd(pgd, *pgd_ref);

	else

		BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_ref));



	/* Below here mismatches are bugs because these lower tables

	   are shared */



	pud = pud_offset(pgd, address);

	pud_ref = pud_offset(pgd_ref, address);

	if (pud_none(*pud_ref))

		return -1;

	if (pud_none(*pud) || pud_page_vaddr(*pud) != pud_page_vaddr(*pud_ref))

		BUG();

	pmd = pmd_offset(pud, address);

	pmd_ref = pmd_offset(pud_ref, address);

	if (pmd_none(*pmd_ref))

		return -1;

	if (pmd_none(*pmd) || pmd_page(*pmd) != pmd_page(*pmd_ref))

		BUG();

	pte_ref = pte_offset_kernel(pmd_ref, address);

	if (!pte_present(*pte_ref))

		return -1;

	pte = pte_offset_kernel(pmd, address);

	/* Don't use pte_page here, because the mappings can point

	   outside mem_map, and the NUMA hash lookup cannot handle

	   that. */

	if (!pte_present(*pte) || pte_pfn(*pte) != pte_pfn(*pte_ref))

		BUG();

	return 0;

#endif

}



int show_unhandled_signals = 1;
@@ -507,6 +557,9 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code) 
	if (is_prefetch(regs, address, error_code))

		return;



	if (is_errata93(regs, address))

		return;



/*

 * Oops. The kernel tried to access some bad page. We'll have to

 * terminate things with extreme prejudice.

arch/x86/mm/fault_64.c

+27 −3
Original line number Diff line number Diff line
@@ -223,6 +223,7 @@ KERN_ERR "******* Your BIOS seems to not contain a fix for K8 errata #93\n" 
KERN_ERR "******* Working around it, but it may cause SEGVs or burn power.\n"

KERN_ERR "******* Please consider a BIOS update.\n"

KERN_ERR "******* Disabling USB legacy in the BIOS may also help.\n";

#endif



/* Workaround for K8 erratum #93 & buggy BIOS.

   BIOS SMM functions are required to use a specific workaround
@@ -230,10 +231,12 @@ KERN_ERR "******* Disabling USB legacy in the BIOS may also help.\n"; 
   A lot of BIOS that didn't get tested properly miss this.

   The OS sees this as a page fault with the upper 32bits of RIP cleared.

   Try to work around it here.

   Note we only handle faults in kernel here. */



   Note we only handle faults in kernel here.

   Does nothing for X86_32

 */

static int is_errata93(struct pt_regs *regs, unsigned long address)

{

#ifdef CONFIG_X86_64

	static int warned;

	if (address != regs->ip)

		return 0;
@@ -249,9 +252,9 @@ static int is_errata93(struct pt_regs *regs, unsigned long address) 
		regs->ip = address;

		return 1;

	}

#endif

	return 0;

}

#endif



static noinline void pgtable_bad(unsigned long address, struct pt_regs *regs,

				 unsigned long error_code)
@@ -278,6 +281,26 @@ static noinline void pgtable_bad(unsigned long address, struct pt_regs *regs, 
 */

static int vmalloc_fault(unsigned long address)

{

#ifdef CONFIG_X86_32

	unsigned long pgd_paddr;

	pmd_t *pmd_k;

	pte_t *pte_k;

	/*

	 * Synchronize this task's top level page-table

	 * with the 'reference' page table.

	 *

	 * Do _not_ use "current" here. We might be inside

	 * an interrupt in the middle of a task switch..

	 */

	pgd_paddr = read_cr3();

	pmd_k = vmalloc_sync_one(__va(pgd_paddr), address);

	if (!pmd_k)

		return -1;

	pte_k = pte_offset_kernel(pmd_k, address);

	if (!pte_present(*pte_k))

		return -1;

	return 0;

#else

	pgd_t *pgd, *pgd_ref;

	pud_t *pud, *pud_ref;

	pmd_t *pmd, *pmd_ref;
@@ -321,6 +344,7 @@ static int vmalloc_fault(unsigned long address) 
	if (!pte_present(*pte) || pte_pfn(*pte) != pte_pfn(*pte_ref))

		BUG();

	return 0;

#endif

}



int show_unhandled_signals = 1;