diff options
| -rw-r--r-- | arch/powerpc/kernel/signal.c | 4 | ||||
| -rw-r--r-- | arch/powerpc/kernel/uprobes.c | 6 | ||||
| -rw-r--r-- | arch/x86/kernel/uprobes.c | 54 | ||||
| -rw-r--r-- | include/linux/uprobes.h | 10 | ||||
| -rw-r--r-- | kernel/events/uprobes.c | 43 | ||||
| -rw-r--r-- | kernel/fork.c | 2 | ||||
| -rw-r--r-- | kernel/trace/trace_uprobe.c | 2 |
7 files changed, 65 insertions, 56 deletions
diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c index a2dc757..3b99711 100644 --- a/arch/powerpc/kernel/signal.c +++ b/arch/powerpc/kernel/signal.c @@ -158,10 +158,8 @@ static int do_signal(struct pt_regs *regs) void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags) { - if (thread_info_flags & _TIF_UPROBE) { - clear_thread_flag(TIF_UPROBE); + if (thread_info_flags & _TIF_UPROBE) uprobe_notify_resume(regs); - } if (thread_info_flags & _TIF_SIGPENDING) do_signal(regs); diff --git a/arch/powerpc/kernel/uprobes.c b/arch/powerpc/kernel/uprobes.c index d2d46d1..bc77834 100644 --- a/arch/powerpc/kernel/uprobes.c +++ b/arch/powerpc/kernel/uprobes.c @@ -64,6 +64,8 @@ int arch_uprobe_pre_xol(struct arch_uprobe *auprobe, struct pt_regs *regs) autask->saved_trap_nr = current->thread.trap_nr; current->thread.trap_nr = UPROBE_TRAP_NR; regs->nip = current->utask->xol_vaddr; + + user_enable_single_step(current); return 0; } @@ -119,6 +121,8 @@ int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs) * to be executed. */ regs->nip = utask->vaddr + MAX_UINSN_BYTES; + + user_disable_single_step(current); return 0; } @@ -162,6 +166,8 @@ void arch_uprobe_abort_xol(struct arch_uprobe *auprobe, struct pt_regs *regs) current->thread.trap_nr = utask->autask.saved_trap_nr; instruction_pointer_set(regs, utask->vaddr); + + user_disable_single_step(current); } /* diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c index aafa555..c71025b 100644 --- a/arch/x86/kernel/uprobes.c +++ b/arch/x86/kernel/uprobes.c @@ -478,6 +478,11 @@ int arch_uprobe_pre_xol(struct arch_uprobe *auprobe, struct pt_regs *regs) regs->ip = current->utask->xol_vaddr; pre_xol_rip_insn(auprobe, regs, autask); + autask->saved_tf = !!(regs->flags & X86_EFLAGS_TF); + regs->flags |= X86_EFLAGS_TF; + if (test_tsk_thread_flag(current, TIF_BLOCKSTEP)) + set_task_blockstep(current, false); + return 0; } @@ -603,6 +608,16 @@ int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs) if (auprobe->fixups & UPROBE_FIX_CALL) result = adjust_ret_addr(regs->sp, correction); + /* + * arch_uprobe_pre_xol() doesn't save the state of TIF_BLOCKSTEP + * so we can get an extra SIGTRAP if we do not clear TF. We need + * to examine the opcode to make it right. + */ + if (utask->autask.saved_tf) + send_sig(SIGTRAP, current, 0); + else if (!(auprobe->fixups & UPROBE_FIX_SETF)) + regs->flags &= ~X86_EFLAGS_TF; + return result; } @@ -647,6 +662,10 @@ void arch_uprobe_abort_xol(struct arch_uprobe *auprobe, struct pt_regs *regs) current->thread.trap_nr = utask->autask.saved_trap_nr; handle_riprel_post_xol(auprobe, regs, NULL); instruction_pointer_set(regs, utask->vaddr); + + /* clear TF if it was set by us in arch_uprobe_pre_xol() */ + if (!utask->autask.saved_tf) + regs->flags &= ~X86_EFLAGS_TF; } /* @@ -676,38 +695,3 @@ bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs) send_sig(SIGTRAP, current, 0); return ret; } - -void arch_uprobe_enable_step(struct arch_uprobe *auprobe) -{ - struct task_struct *task = current; - struct arch_uprobe_task *autask = &task->utask->autask; - struct pt_regs *regs = task_pt_regs(task); - - autask->saved_tf = !!(regs->flags & X86_EFLAGS_TF); - - regs->flags |= X86_EFLAGS_TF; - if (test_tsk_thread_flag(task, TIF_BLOCKSTEP)) - set_task_blockstep(task, false); -} - -void arch_uprobe_disable_step(struct arch_uprobe *auprobe) -{ - struct task_struct *task = current; - struct arch_uprobe_task *autask = &task->utask->autask; - bool trapped = (task->utask->state == UTASK_SSTEP_TRAPPED); - struct pt_regs *regs = task_pt_regs(task); - /* - * The state of TIF_BLOCKSTEP was not saved so we can get an extra - * SIGTRAP if we do not clear TF. We need to examine the opcode to - * make it right. - */ - if (unlikely(trapped)) { - if (!autask->saved_tf) - regs->flags &= ~X86_EFLAGS_TF; - } else { - if (autask->saved_tf) - send_sig(SIGTRAP, task, 0); - else if (!(auprobe->fixups & UPROBE_FIX_SETF)) - regs->flags &= ~X86_EFLAGS_TF; - } -} diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h index 2459457..4f628a6 100644 --- a/include/linux/uprobes.h +++ b/include/linux/uprobes.h @@ -97,12 +97,12 @@ extern int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_con extern void uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consumer *uc); extern int uprobe_mmap(struct vm_area_struct *vma); extern void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned long end); +extern void uprobe_start_dup_mmap(void); +extern void uprobe_end_dup_mmap(void); extern void uprobe_dup_mmap(struct mm_struct *oldmm, struct mm_struct *newmm); extern void uprobe_free_utask(struct task_struct *t); extern void uprobe_copy_process(struct task_struct *t); extern unsigned long __weak uprobe_get_swbp_addr(struct pt_regs *regs); -extern void __weak arch_uprobe_enable_step(struct arch_uprobe *arch); -extern void __weak arch_uprobe_disable_step(struct arch_uprobe *arch); extern int uprobe_post_sstep_notifier(struct pt_regs *regs); extern int uprobe_pre_sstep_notifier(struct pt_regs *regs); extern void uprobe_notify_resume(struct pt_regs *regs); @@ -129,6 +129,12 @@ static inline void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned long end) { } +static inline void uprobe_start_dup_mmap(void) +{ +} +static inline void uprobe_end_dup_mmap(void) +{ +} static inline void uprobe_dup_mmap(struct mm_struct *oldmm, struct mm_struct *newmm) { diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 5cc4e7e..dea7acf 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -33,6 +33,7 @@ #include <linux/ptrace.h> /* user_enable_single_step */ #include <linux/kdebug.h> /* notifier mechanism */ #include "../../mm/internal.h" /* munlock_vma_page */ +#include <linux/percpu-rwsem.h> #include <linux/uprobes.h> @@ -71,6 +72,8 @@ static struct mutex uprobes_mutex[UPROBES_HASH_SZ]; static struct mutex uprobes_mmap_mutex[UPROBES_HASH_SZ]; #define uprobes_mmap_hash(v) (&uprobes_mmap_mutex[((unsigned long)(v)) % UPROBES_HASH_SZ]) +static struct percpu_rw_semaphore dup_mmap_sem; + /* * uprobe_events allows us to skip the uprobe_mmap if there are no uprobe * events active at this time. Probably a fine grained per inode count is @@ -766,10 +769,13 @@ static int register_for_each_vma(struct uprobe *uprobe, bool is_register) struct map_info *info; int err = 0; + percpu_down_write(&dup_mmap_sem); info = build_map_info(uprobe->inode->i_mapping, uprobe->offset, is_register); - if (IS_ERR(info)) - return PTR_ERR(info); + if (IS_ERR(info)) { + err = PTR_ERR(info); + goto out; + } while (info) { struct mm_struct *mm = info->mm; @@ -799,7 +805,8 @@ static int register_for_each_vma(struct uprobe *uprobe, bool is_register) mmput(mm); info = free_map_info(info); } - + out: + percpu_up_write(&dup_mmap_sem); return err; } @@ -1131,6 +1138,16 @@ void uprobe_clear_state(struct mm_struct *mm) kfree(area); } +void uprobe_start_dup_mmap(void) +{ + percpu_down_read(&dup_mmap_sem); +} + +void uprobe_end_dup_mmap(void) +{ + percpu_up_read(&dup_mmap_sem); +} + void uprobe_dup_mmap(struct mm_struct *oldmm, struct mm_struct *newmm) { newmm->uprobes_state.xol_area = NULL; @@ -1199,6 +1216,11 @@ static unsigned long xol_get_insn_slot(struct uprobe *uprobe, unsigned long slot vaddr = kmap_atomic(area->page); memcpy(vaddr + offset, uprobe->arch.insn, MAX_UINSN_BYTES); kunmap_atomic(vaddr); + /* + * We probably need flush_icache_user_range() but it needs vma. + * This should work on supported architectures too. + */ + flush_dcache_page(area->page); return current->utask->xol_vaddr; } @@ -1430,16 +1452,6 @@ static struct uprobe *find_active_uprobe(unsigned long bp_vaddr, int *is_swbp) return uprobe; } -void __weak arch_uprobe_enable_step(struct arch_uprobe *arch) -{ - user_enable_single_step(current); -} - -void __weak arch_uprobe_disable_step(struct arch_uprobe *arch) -{ - user_disable_single_step(current); -} - /* * Run handler and ask thread to singlestep. * Ensure all non-fatal signals cannot interrupt thread while it singlesteps. @@ -1493,7 +1505,6 @@ static void handle_swbp(struct pt_regs *regs) goto out; if (!pre_ssout(uprobe, regs, bp_vaddr)) { - arch_uprobe_enable_step(&uprobe->arch); utask->active_uprobe = uprobe; utask->state = UTASK_SSTEP; return; @@ -1525,7 +1536,6 @@ static void handle_singlestep(struct uprobe_task *utask, struct pt_regs *regs) else WARN_ON_ONCE(1); - arch_uprobe_disable_step(&uprobe->arch); put_uprobe(uprobe); utask->active_uprobe = NULL; utask->state = UTASK_RUNNING; @@ -1604,6 +1614,9 @@ static int __init init_uprobes(void) mutex_init(&uprobes_mmap_mutex[i]); } + if (percpu_init_rwsem(&dup_mmap_sem)) + return -ENOMEM; + return register_die_notifier(&uprobe_exception_nb); } module_init(init_uprobes); diff --git a/kernel/fork.c b/kernel/fork.c index 8b20ab7..c497e57 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -352,6 +352,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm) unsigned long charge; struct mempolicy *pol; + uprobe_start_dup_mmap(); down_write(&oldmm->mmap_sem); flush_cache_dup_mm(oldmm); uprobe_dup_mmap(oldmm, mm); @@ -469,6 +470,7 @@ out: up_write(&mm->mmap_sem); flush_tlb_mm(oldmm); up_write(&oldmm->mmap_sem); + uprobe_end_dup_mmap(); return retval; fail_nomem_anon_vma_fork: mpol_put(pol); diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 4ff9ca4..9614db8 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -189,7 +189,7 @@ static int create_trace_uprobe(int argc, char **argv) if (argv[0][0] == '-') is_delete = true; else if (argv[0][0] != 'p') { - pr_info("Probe definition must be started with 'p', 'r' or" " '-'.\n"); + pr_info("Probe definition must be started with 'p' or '-'.\n"); return -EINVAL; } |
