From b11b53342773361f3353b285eb6a3fd6074e7997 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Mon, 7 Dec 2009 12:51:43 +0100 Subject: [PATCH] [S390] Improve address space mode selection. Introduce user_mode to replace the two variables switch_amode and s390_noexec. There are three valid combinations of the old values: 1) switch_amode == 0 && s390_noexec == 0 2) switch_amode == 1 && s390_noexec == 0 3) switch_amode == 1 && s390_noexec == 1 They get replaced by 1) user_mode == HOME_SPACE_MODE 2) user_mode == PRIMARY_SPACE_MODE 3) user_mode == SECONDARY_SPACE_MODE The new kernel parameter user_mode=[primary,secondary,home] lets you choose the address space mode the user space processes should use. In addition the CONFIG_S390_SWITCH_AMODE config option is removed. Signed-off-by: Martin Schwidefsky --- arch/s390/Kconfig | 15 ------------ arch/s390/defconfig | 1 - arch/s390/include/asm/mmu_context.h | 4 ++-- arch/s390/include/asm/pgalloc.h | 3 ++- arch/s390/include/asm/setup.h | 17 +++++--------- arch/s390/kernel/setup.c | 36 ++++++++++++++++------------- arch/s390/kernel/vdso.c | 9 ++++---- arch/s390/kvm/Kconfig | 1 - arch/s390/lib/uaccess_mvcos.c | 4 ---- arch/s390/mm/fault.c | 4 ++-- arch/s390/mm/pgtable.c | 2 +- 11 files changed, 38 insertions(+), 58 deletions(-) diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 16c673096a2..c80235206c0 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -220,23 +220,8 @@ config AUDIT_ARCH bool default y -config S390_SWITCH_AMODE - bool "Switch kernel/user addressing modes" - help - This option allows to switch the addressing modes of kernel and user - space. The kernel parameter switch_amode=on will enable this feature, - default is disabled. Enabling this (via kernel parameter) on machines - earlier than IBM System z9-109 EC/BC will reduce system performance. - - Note that this option will also be selected by selecting the execute - protection option below. Enabling the execute protection via the - noexec kernel parameter will also switch the addressing modes, - independent of the switch_amode kernel parameter. - - config S390_EXEC_PROTECT bool "Data execute protection" - select S390_SWITCH_AMODE help This option allows to enable a buffer overflow protection for user space programs and it also selects the addressing mode option above. diff --git a/arch/s390/defconfig b/arch/s390/defconfig index ab4464486b7..f4e53c6708d 100644 --- a/arch/s390/defconfig +++ b/arch/s390/defconfig @@ -185,7 +185,6 @@ CONFIG_HOTPLUG_CPU=y CONFIG_COMPAT=y CONFIG_SYSVIPC_COMPAT=y CONFIG_AUDIT_ARCH=y -CONFIG_S390_SWITCH_AMODE=y CONFIG_S390_EXEC_PROTECT=y # diff --git a/arch/s390/include/asm/mmu_context.h b/arch/s390/include/asm/mmu_context.h index fc7edd6f41b..976e273988c 100644 --- a/arch/s390/include/asm/mmu_context.h +++ b/arch/s390/include/asm/mmu_context.h @@ -36,7 +36,7 @@ static inline int init_new_context(struct task_struct *tsk, mm->context.has_pgste = 1; mm->context.alloc_pgste = 1; } else { - mm->context.noexec = s390_noexec; + mm->context.noexec = (user_mode == SECONDARY_SPACE_MODE); mm->context.has_pgste = 0; mm->context.alloc_pgste = 0; } @@ -58,7 +58,7 @@ static inline void update_mm(struct mm_struct *mm, struct task_struct *tsk) pgd_t *pgd = mm->pgd; S390_lowcore.user_asce = mm->context.asce_bits | __pa(pgd); - if (switch_amode) { + if (user_mode != HOME_SPACE_MODE) { /* Load primary space page table origin. */ pgd = mm->context.noexec ? get_shadow_table(pgd) : pgd; S390_lowcore.user_exec_asce = mm->context.asce_bits | __pa(pgd); diff --git a/arch/s390/include/asm/pgalloc.h b/arch/s390/include/asm/pgalloc.h index ddad5903341..68940d0bad9 100644 --- a/arch/s390/include/asm/pgalloc.h +++ b/arch/s390/include/asm/pgalloc.h @@ -143,7 +143,8 @@ static inline pgd_t *pgd_alloc(struct mm_struct *mm) spin_lock_init(&mm->context.list_lock); INIT_LIST_HEAD(&mm->context.crst_list); INIT_LIST_HEAD(&mm->context.pgtable_list); - return (pgd_t *) crst_table_alloc(mm, s390_noexec); + return (pgd_t *) + crst_table_alloc(mm, user_mode == SECONDARY_SPACE_MODE); } #define pgd_free(mm, pgd) crst_table_free(mm, (unsigned long *) pgd) diff --git a/arch/s390/include/asm/setup.h b/arch/s390/include/asm/setup.h index e37478e8728..52a779c337e 100644 --- a/arch/s390/include/asm/setup.h +++ b/arch/s390/include/asm/setup.h @@ -49,17 +49,12 @@ extern unsigned long memory_end; void detect_memory_layout(struct mem_chunk chunk[]); -#ifdef CONFIG_S390_SWITCH_AMODE -extern unsigned int switch_amode; -#else -#define switch_amode (0) -#endif - -#ifdef CONFIG_S390_EXEC_PROTECT -extern unsigned int s390_noexec; -#else -#define s390_noexec (0) -#endif +#define PRIMARY_SPACE_MODE 0 +#define ACCESS_REGISTER_MODE 1 +#define SECONDARY_SPACE_MODE 2 +#define HOME_SPACE_MODE 3 + +extern unsigned int user_mode; /* * Machine features detected in head.S diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c index 061479ff029..0663287fa1b 100644 --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -305,9 +305,8 @@ static int __init early_parse_mem(char *p) } early_param("mem", early_parse_mem); -#ifdef CONFIG_S390_SWITCH_AMODE -unsigned int switch_amode = 0; -EXPORT_SYMBOL_GPL(switch_amode); +unsigned int user_mode = HOME_SPACE_MODE; +EXPORT_SYMBOL_GPL(user_mode); static int set_amode_and_uaccess(unsigned long user_amode, unsigned long user32_amode) @@ -340,23 +339,29 @@ static int set_amode_and_uaccess(unsigned long user_amode, */ static int __init early_parse_switch_amode(char *p) { - switch_amode = 1; + if (user_mode != SECONDARY_SPACE_MODE) + user_mode = PRIMARY_SPACE_MODE; return 0; } early_param("switch_amode", early_parse_switch_amode); -#else /* CONFIG_S390_SWITCH_AMODE */ -static inline int set_amode_and_uaccess(unsigned long user_amode, - unsigned long user32_amode) +static int __init early_parse_user_mode(char *p) { + if (p && strcmp(p, "primary") == 0) + user_mode = PRIMARY_SPACE_MODE; +#ifdef CONFIG_S390_EXEC_PROTECT + else if (p && strcmp(p, "secondary") == 0) + user_mode = SECONDARY_SPACE_MODE; +#endif + else if (!p || strcmp(p, "home") == 0) + user_mode = HOME_SPACE_MODE; + else + return 1; return 0; } -#endif /* CONFIG_S390_SWITCH_AMODE */ +early_param("user_mode", early_parse_user_mode); #ifdef CONFIG_S390_EXEC_PROTECT -unsigned int s390_noexec = 0; -EXPORT_SYMBOL_GPL(s390_noexec); - /* * Enable execute protection? */ @@ -364,8 +369,7 @@ static int __init early_parse_noexec(char *p) { if (!strncmp(p, "off", 3)) return 0; - switch_amode = 1; - s390_noexec = 1; + user_mode = SECONDARY_SPACE_MODE; return 0; } early_param("noexec", early_parse_noexec); @@ -373,7 +377,7 @@ early_param("noexec", early_parse_noexec); static void setup_addressing_mode(void) { - if (s390_noexec) { + if (user_mode == SECONDARY_SPACE_MODE) { if (set_amode_and_uaccess(PSW_ASC_SECONDARY, PSW32_ASC_SECONDARY)) pr_info("Execute protection active, " @@ -381,7 +385,7 @@ static void setup_addressing_mode(void) else pr_info("Execute protection active, " "mvcos not available\n"); - } else if (switch_amode) { + } else if (user_mode == PRIMARY_SPACE_MODE) { if (set_amode_and_uaccess(PSW_ASC_PRIMARY, PSW32_ASC_PRIMARY)) pr_info("Address spaces switched, " "mvcos available\n"); @@ -411,7 +415,7 @@ setup_lowcore(void) lc->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY; lc->restart_psw.addr = PSW_ADDR_AMODE | (unsigned long) restart_int_handler; - if (switch_amode) + if (user_mode != HOME_SPACE_MODE) lc->restart_psw.mask |= PSW_ASC_HOME; lc->external_new_psw.mask = psw_kernel_bits; lc->external_new_psw.addr = diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c index adfb32aa6d5..5f99e66c51c 100644 --- a/arch/s390/kernel/vdso.c +++ b/arch/s390/kernel/vdso.c @@ -86,7 +86,8 @@ static void vdso_init_data(struct vdso_data *vd) unsigned int facility_list; facility_list = stfl(); - vd->ectg_available = switch_amode && (facility_list & 1); + vd->ectg_available = + user_mode != HOME_SPACE_MODE && (facility_list & 1); } #ifdef CONFIG_64BIT @@ -114,7 +115,7 @@ int vdso_alloc_per_cpu(int cpu, struct _lowcore *lowcore) lowcore->vdso_per_cpu_data = __LC_PASTE; - if (!switch_amode || !vdso_enabled) + if (user_mode == HOME_SPACE_MODE || !vdso_enabled) return 0; segment_table = __get_free_pages(GFP_KERNEL, SEGMENT_ORDER); @@ -160,7 +161,7 @@ void vdso_free_per_cpu(int cpu, struct _lowcore *lowcore) unsigned long segment_table, page_table, page_frame; u32 *psal, *aste; - if (!switch_amode || !vdso_enabled) + if (user_mode == HOME_SPACE_MODE || !vdso_enabled) return; psal = (u32 *)(addr_t) lowcore->paste[4]; @@ -184,7 +185,7 @@ static void __vdso_init_cr5(void *dummy) static void vdso_init_cr5(void) { - if (switch_amode && vdso_enabled) + if (user_mode != HOME_SPACE_MODE && vdso_enabled) on_each_cpu(__vdso_init_cr5, NULL, 1); } #endif /* CONFIG_64BIT */ diff --git a/arch/s390/kvm/Kconfig b/arch/s390/kvm/Kconfig index bf164fc2186..6ee55ae84ce 100644 --- a/arch/s390/kvm/Kconfig +++ b/arch/s390/kvm/Kconfig @@ -20,7 +20,6 @@ config KVM depends on HAVE_KVM && EXPERIMENTAL select PREEMPT_NOTIFIERS select ANON_INODES - select S390_SWITCH_AMODE ---help--- Support hosting paravirtualized guest machines using the SIE virtualization capability on the mainframe. This should work diff --git a/arch/s390/lib/uaccess_mvcos.c b/arch/s390/lib/uaccess_mvcos.c index 58da3f46121..60455f104ea 100644 --- a/arch/s390/lib/uaccess_mvcos.c +++ b/arch/s390/lib/uaccess_mvcos.c @@ -162,7 +162,6 @@ static size_t clear_user_mvcos(size_t size, void __user *to) return size; } -#ifdef CONFIG_S390_SWITCH_AMODE static size_t strnlen_user_mvcos(size_t count, const char __user *src) { char buf[256]; @@ -200,7 +199,6 @@ static size_t strncpy_from_user_mvcos(size_t count, const char __user *src, } while ((len_str == len) && (done < count)); return done; } -#endif /* CONFIG_S390_SWITCH_AMODE */ struct uaccess_ops uaccess_mvcos = { .copy_from_user = copy_from_user_mvcos_check, @@ -215,7 +213,6 @@ struct uaccess_ops uaccess_mvcos = { .futex_atomic_cmpxchg = futex_atomic_cmpxchg_std, }; -#ifdef CONFIG_S390_SWITCH_AMODE struct uaccess_ops uaccess_mvcos_switch = { .copy_from_user = copy_from_user_mvcos, .copy_from_user_small = copy_from_user_mvcos, @@ -228,4 +225,3 @@ struct uaccess_ops uaccess_mvcos_switch = { .futex_atomic_op = futex_atomic_op_pt, .futex_atomic_cmpxchg = futex_atomic_cmpxchg_pt, }; -#endif diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index 3df5b918cfe..77108e34fc1 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -112,7 +112,7 @@ static inline int user_space_fault(unsigned long trans_exc_code) if (trans_exc_code == 2) /* Access via secondary space, set_fs setting decides */ return current->thread.mm_segment.ar4; - if (!switch_amode) + if (user_mode == HOME_SPACE_MODE) /* User space if the access has been done via home space. */ return trans_exc_code == 3; /* @@ -168,7 +168,7 @@ static void do_no_context(struct pt_regs *regs, unsigned long error_code, * terminate things with extreme prejudice. */ address = trans_exc_code & __FAIL_ADDR_MASK; - if (user_space_fault(trans_exc_code) == 0) + if (!user_space_fault(trans_exc_code)) printk(KERN_ALERT "Unable to handle kernel pointer dereference" " at virtual kernel address %p\n", (void *)address); else diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c index 2757c5616a0..ad621e06ada 100644 --- a/arch/s390/mm/pgtable.c +++ b/arch/s390/mm/pgtable.c @@ -269,7 +269,7 @@ int s390_enable_sie(void) struct mm_struct *mm, *old_mm; /* Do we have switched amode? If no, we cannot do sie */ - if (!switch_amode) + if (user_mode == HOME_SPACE_MODE) return -EINVAL; /* Do we have pgstes? if yes, we are done */ -- 2.39.2