From 593befa6ab74a805e4f503c8c737c3cffa8066b6 Mon Sep 17 00:00:00 2001 From: Dominik Dingel Date: Thu, 23 Oct 2014 12:07:44 +0200 Subject: mm: introduce mm_forbids_zeropage function Add a new function stub to allow architectures to disable for an mm_structthe backing of non-present, anonymous pages with read-only empty zero pages. Signed-off-by: Dominik Dingel Reviewed-by: Paolo Bonzini Signed-off-by: Martin Schwidefsky --- include/linux/mm.h | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'include') diff --git a/include/linux/mm.h b/include/linux/mm.h index 27eb1bfbe704..ab7dadca4ea5 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -56,6 +56,17 @@ extern int sysctl_legacy_va_layout; #define __pa_symbol(x) __pa(RELOC_HIDE((unsigned long)(x), 0)) #endif +/* + * To prevent common memory management code establishing + * a zero page mapping on a read fault. + * This macro should be defined within . + * s390 does this to prevent multiplexing of hardware bits + * related to the physical page in case of virtualization. + */ +#ifndef mm_forbids_zeropage +#define mm_forbids_zeropage(X) (0) +#endif + extern unsigned long sysctl_user_reserve_kbytes; extern unsigned long sysctl_admin_reserve_kbytes; -- cgit v1.2.3 From f7f242ff004499e0904d3664713dfba01f24c408 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Wed, 15 Oct 2014 12:17:34 +0200 Subject: kprobes: introduce weak arch_check_ftrace_location() helper function Introduce weak arch_check_ftrace_location() helper function which architectures can override in order to implement handling of kprobes on function tracer call sites on their own, without depending on common code or implementing the KPROBES_ON_FTRACE feature. Signed-off-by: Heiko Carstens Acked-by: Masami Hiramatsu Acked-by: Steven Rostedt Signed-off-by: Martin Schwidefsky --- include/linux/kprobes.h | 1 + kernel/kprobes.c | 18 +++++++++++------- 2 files changed, 12 insertions(+), 7 deletions(-) (limited to 'include') diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index f7296e57d614..5297f9fa0ef2 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -335,6 +335,7 @@ extern void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, extern int arch_prepare_kprobe_ftrace(struct kprobe *p); #endif +int arch_check_ftrace_location(struct kprobe *p); /* Get the kprobe at this addr (if any) - called with preemption disabled */ struct kprobe *get_kprobe(void *addr); diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 3995f546d0f3..317eb8ad28dd 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1410,16 +1410,10 @@ static inline int check_kprobe_rereg(struct kprobe *p) return ret; } -static int check_kprobe_address_safe(struct kprobe *p, - struct module **probed_mod) +int __weak arch_check_ftrace_location(struct kprobe *p) { - int ret = 0; unsigned long ftrace_addr; - /* - * If the address is located on a ftrace nop, set the - * breakpoint to the following instruction. - */ ftrace_addr = ftrace_location((unsigned long)p->addr); if (ftrace_addr) { #ifdef CONFIG_KPROBES_ON_FTRACE @@ -1431,7 +1425,17 @@ static int check_kprobe_address_safe(struct kprobe *p, return -EINVAL; #endif } + return 0; +} +static int check_kprobe_address_safe(struct kprobe *p, + struct module **probed_mod) +{ + int ret; + + ret = arch_check_ftrace_location(p); + if (ret) + return ret; jump_label_lock(); preempt_disable(); -- cgit v1.2.3 From fcbe08d66f57c368e77ca729dd01e6b539ffb3ff Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Fri, 24 Oct 2014 10:52:29 +0200 Subject: s390/mm: pmdp_get_and_clear_full optimization Analog to ptep_get_and_clear_full define a variant of the pmpd_get_and_clear primitive which gets the full hint from the mmu_gather struct. This allows s390 to avoid a costly instruction when destroying an address space. Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/pgtable.h | 13 +++++++++++++ include/asm-generic/pgtable.h | 11 +++++++++++ mm/huge_memory.c | 3 ++- 3 files changed, 26 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index 5ef1a266936a..5e102422c9ab 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -1651,6 +1651,19 @@ static inline pmd_t pmdp_get_and_clear(struct mm_struct *mm, return pmd; } +#define __HAVE_ARCH_PMDP_GET_AND_CLEAR_FULL +static inline pmd_t pmdp_get_and_clear_full(struct mm_struct *mm, + unsigned long address, + pmd_t *pmdp, int full) +{ + pmd_t pmd = *pmdp; + + if (!full) + pmdp_flush_lazy(mm, address, pmdp); + pmd_clear(pmdp); + return pmd; +} + #define __HAVE_ARCH_PMDP_CLEAR_FLUSH static inline pmd_t pmdp_clear_flush(struct vm_area_struct *vma, unsigned long address, pmd_t *pmdp) diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index 752e30d63904..177d5973b132 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -103,6 +103,17 @@ static inline pmd_t pmdp_get_and_clear(struct mm_struct *mm, #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ #endif +#ifndef __HAVE_ARCH_PMDP_GET_AND_CLEAR_FULL +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +static inline pmd_t pmdp_get_and_clear_full(struct mm_struct *mm, + unsigned long address, pmd_t *pmdp, + int full) +{ + return pmdp_get_and_clear(mm, address, pmdp); +} +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ +#endif + #ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm, unsigned long address, pte_t *ptep, diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 7e9c15cb93a9..6a37f1b2ed1e 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1400,7 +1400,8 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, * pgtable_trans_huge_withdraw after finishing pmdp related * operations. */ - orig_pmd = pmdp_get_and_clear(tlb->mm, addr, pmd); + orig_pmd = pmdp_get_and_clear_full(tlb->mm, addr, pmd, + tlb->fullmm); tlb_remove_pmd_tlb_entry(tlb, pmd, addr); pgtable = pgtable_trans_huge_withdraw(tlb->mm, pmd); if (is_huge_zero_pmd(orig_pmd)) { -- cgit v1.2.3