From d7627467b7a8dd6944885290a03a07ceb28c10eb Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 17 Aug 2010 23:52:56 +0100 Subject: Make do_execve() take a const filename pointer Make do_execve() take a const filename pointer so that kernel_execve() compiles correctly on ARM: arch/arm/kernel/sys_arm.c:88: warning: passing argument 1 of 'do_execve' discards qualifiers from pointer target type This also requires the argv and envp arguments to be consted twice, once for the pointer array and once for the strings the array points to. This is because do_execve() passes a pointer to the filename (now const) to copy_strings_kernel(). A simpler alternative would be to cast the filename pointer in do_execve() when it's passed to copy_strings_kernel(). do_execve() may not change any of the strings it is passed as part of the argv or envp lists as they are some of them in .rodata, so marking these strings as const should be fine. Further kernel_execve() and sys_execve() need to be changed to match. This has been test built on x86_64, frv, arm and mips. Signed-off-by: David Howells Tested-by: Ralf Baechle Acked-by: Russell King Signed-off-by: Linus Torvalds --- arch/s390/kernel/process.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'arch/s390') diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c index 7eafaf2662b..d3a2d1c6438 100644 --- a/arch/s390/kernel/process.c +++ b/arch/s390/kernel/process.c @@ -267,8 +267,9 @@ asmlinkage void execve_tail(void) /* * sys_execve() executes a new program. */ -SYSCALL_DEFINE3(execve, const char __user *, name, char __user * __user *, argv, - char __user * __user *, envp) +SYSCALL_DEFINE3(execve, const char __user *, name, + const char __user *const __user *, argv, + const char __user *const __user *, envp) { struct pt_regs *regs = task_pt_regs(current); char *filename; -- cgit v1.2.3-70-g09d2 From 7af048dc7639db5202c56fecf2346c310647a218 Mon Sep 17 00:00:00 2001 From: Sebastian Ott Date: Tue, 24 Aug 2010 09:26:20 +0200 Subject: [S390] s390: fix build error (sys_execve) fix this build error: arch/s390/kernel/process.c:272: error: conflicting types for 'sys_execve' arch/s390/kernel/entry.h:45: error: previous declaration of 'sys_execve' was here make[1]: *** [arch/s390/kernel/process.o] Error 1 make: *** [arch/s390/kernel] Error 2 introduced by d7627467b7a8dd6944885290a03a07ceb28c10eb Signed-off-by: Sebastian Ott Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/entry.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/s390') diff --git a/arch/s390/kernel/entry.h b/arch/s390/kernel/entry.h index 403fb430a89..ff579b6bde0 100644 --- a/arch/s390/kernel/entry.h +++ b/arch/s390/kernel/entry.h @@ -42,8 +42,8 @@ long sys_clone(unsigned long newsp, unsigned long clone_flags, int __user *parent_tidptr, int __user *child_tidptr); long sys_vfork(void); void execve_tail(void); -long sys_execve(const char __user *name, char __user * __user *argv, - char __user * __user *envp); +long sys_execve(const char __user *name, const char __user *const __user *argv, + const char __user *const __user *envp); long sys_sigsuspend(int history0, int history1, old_sigset_t mask); long sys_sigaction(int sig, const struct old_sigaction __user *act, struct old_sigaction __user *oact); -- cgit v1.2.3-70-g09d2 From 050eef364ad700590a605a0749f825cab4834b1e Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Tue, 24 Aug 2010 09:26:21 +0200 Subject: [S390] fix tlb flushing vs. concurrent /proc accesses The tlb flushing code uses the mm_users field of the mm_struct to decide if each page table entry needs to be flushed individually with IPTE or if a global flush for the mm_struct is sufficient after all page table updates have been done. The comment for mm_users says "How many users with user space?" but the /proc code increases mm_users after it found the process structure by pid without creating a new user process. Which makes mm_users useless for the decision between the two tlb flusing methods. The current code can be confused to not flush tlb entries by a concurrent access to /proc files if e.g. a fork is in progres. The solution for this problem is to make the tlb flushing logic independent from the mm_users field. Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/hugetlb.h | 4 +++- arch/s390/include/asm/mmu.h | 2 ++ arch/s390/include/asm/mmu_context.h | 9 +++++++++ arch/s390/include/asm/pgtable.h | 6 ++++-- arch/s390/include/asm/tlb.h | 3 +-- arch/s390/include/asm/tlbflush.h | 6 +++++- arch/s390/kernel/smp.c | 2 ++ arch/s390/mm/init.c | 2 ++ 8 files changed, 28 insertions(+), 6 deletions(-) (limited to 'arch/s390') diff --git a/arch/s390/include/asm/hugetlb.h b/arch/s390/include/asm/hugetlb.h index 670a1d1745d..bb8343d157b 100644 --- a/arch/s390/include/asm/hugetlb.h +++ b/arch/s390/include/asm/hugetlb.h @@ -97,6 +97,7 @@ static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm, { pte_t pte = huge_ptep_get(ptep); + mm->context.flush_mm = 1; pmd_clear((pmd_t *) ptep); return pte; } @@ -167,7 +168,8 @@ static inline void huge_ptep_invalidate(struct mm_struct *mm, ({ \ pte_t __pte = huge_ptep_get(__ptep); \ if (pte_write(__pte)) { \ - if (atomic_read(&(__mm)->mm_users) > 1 || \ + (__mm)->context.flush_mm = 1; \ + if (atomic_read(&(__mm)->context.attach_count) > 1 || \ (__mm) != current->active_mm) \ huge_ptep_invalidate(__mm, __addr, __ptep); \ set_huge_pte_at(__mm, __addr, __ptep, \ diff --git a/arch/s390/include/asm/mmu.h b/arch/s390/include/asm/mmu.h index 99e3409102b..78522cdefdd 100644 --- a/arch/s390/include/asm/mmu.h +++ b/arch/s390/include/asm/mmu.h @@ -2,6 +2,8 @@ #define __MMU_H typedef struct { + atomic_t attach_count; + unsigned int flush_mm; spinlock_t list_lock; struct list_head crst_list; struct list_head pgtable_list; diff --git a/arch/s390/include/asm/mmu_context.h b/arch/s390/include/asm/mmu_context.h index 976e273988c..a6f0e7cc9cd 100644 --- a/arch/s390/include/asm/mmu_context.h +++ b/arch/s390/include/asm/mmu_context.h @@ -11,11 +11,14 @@ #include #include +#include #include static inline int init_new_context(struct task_struct *tsk, struct mm_struct *mm) { + atomic_set(&mm->context.attach_count, 0); + mm->context.flush_mm = 0; mm->context.asce_bits = _ASCE_TABLE_LENGTH | _ASCE_USER_BITS; #ifdef CONFIG_64BIT mm->context.asce_bits |= _ASCE_TYPE_REGION3; @@ -76,6 +79,12 @@ static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, { cpumask_set_cpu(smp_processor_id(), mm_cpumask(next)); update_mm(next, tsk); + atomic_dec(&prev->context.attach_count); + WARN_ON(atomic_read(&prev->context.attach_count) < 0); + atomic_inc(&next->context.attach_count); + /* Check for TLBs not flushed yet */ + if (next->context.flush_mm) + __tlb_flush_mm(next); } #define enter_lazy_tlb(mm,tsk) do { } while (0) diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index 89a504c3f12..3157441ee1d 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -880,7 +880,8 @@ static inline void ptep_invalidate(struct mm_struct *mm, #define ptep_get_and_clear(__mm, __address, __ptep) \ ({ \ pte_t __pte = *(__ptep); \ - if (atomic_read(&(__mm)->mm_users) > 1 || \ + (__mm)->context.flush_mm = 1; \ + if (atomic_read(&(__mm)->context.attach_count) > 1 || \ (__mm) != current->active_mm) \ ptep_invalidate(__mm, __address, __ptep); \ else \ @@ -923,7 +924,8 @@ static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm, ({ \ pte_t __pte = *(__ptep); \ if (pte_write(__pte)) { \ - if (atomic_read(&(__mm)->mm_users) > 1 || \ + (__mm)->context.flush_mm = 1; \ + if (atomic_read(&(__mm)->context.attach_count) > 1 || \ (__mm) != current->active_mm) \ ptep_invalidate(__mm, __addr, __ptep); \ set_pte_at(__mm, __addr, __ptep, pte_wrprotect(__pte)); \ diff --git a/arch/s390/include/asm/tlb.h b/arch/s390/include/asm/tlb.h index 81150b05368..fd1c00d08bf 100644 --- a/arch/s390/include/asm/tlb.h +++ b/arch/s390/include/asm/tlb.h @@ -50,8 +50,7 @@ static inline struct mmu_gather *tlb_gather_mmu(struct mm_struct *mm, struct mmu_gather *tlb = &get_cpu_var(mmu_gathers); tlb->mm = mm; - tlb->fullmm = full_mm_flush || (num_online_cpus() == 1) || - (atomic_read(&mm->mm_users) <= 1 && mm == current->active_mm); + tlb->fullmm = full_mm_flush; tlb->nr_ptes = 0; tlb->nr_pxds = TLB_NR_PTRS; if (tlb->fullmm) diff --git a/arch/s390/include/asm/tlbflush.h b/arch/s390/include/asm/tlbflush.h index 304cffa623e..29d5d6d4bec 100644 --- a/arch/s390/include/asm/tlbflush.h +++ b/arch/s390/include/asm/tlbflush.h @@ -94,8 +94,12 @@ static inline void __tlb_flush_mm(struct mm_struct * mm) static inline void __tlb_flush_mm_cond(struct mm_struct * mm) { - if (atomic_read(&mm->mm_users) <= 1 && mm == current->active_mm) + spin_lock(&mm->page_table_lock); + if (mm->context.flush_mm) { __tlb_flush_mm(mm); + mm->context.flush_mm = 0; + } + spin_unlock(&mm->page_table_lock); } /* diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c index 541053ed234..8127ebd59c4 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -583,6 +583,7 @@ int __cpuinit __cpu_up(unsigned int cpu) sf->gprs[9] = (unsigned long) sf; cpu_lowcore->save_area[15] = (unsigned long) sf; __ctl_store(cpu_lowcore->cregs_save_area, 0, 15); + atomic_inc(&init_mm.context.attach_count); asm volatile( " stam 0,15,0(%0)" : : "a" (&cpu_lowcore->access_regs_save_area) : "memory"); @@ -659,6 +660,7 @@ void __cpu_die(unsigned int cpu) while (sigp_p(0, cpu, sigp_set_prefix) == sigp_busy) udelay(10); smp_free_lowcore(cpu); + atomic_dec(&init_mm.context.attach_count); pr_info("Processor %d stopped\n", cpu); } diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c index acc91c75bc9..30eb6d02ddb 100644 --- a/arch/s390/mm/init.c +++ b/arch/s390/mm/init.c @@ -74,6 +74,8 @@ void __init paging_init(void) __ctl_load(S390_lowcore.kernel_asce, 13, 13); __raw_local_irq_ssm(ssm_mask); + atomic_set(&init_mm.context.attach_count, 1); + sparse_memory_present_with_active_regions(MAX_NUMNODES); sparse_init(); memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); -- cgit v1.2.3-70-g09d2