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Merge branch 'uprobes/core' of git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc into perf/core

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Pull uprobes fixes, cleanups and preparation for the ARM port from Oleg Nesterov.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Ingo Molnar 2012-12-08 15:50:23 +01:00
commit 7e0dd574cd
7 changed files with 65 additions and 56 deletions
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4
arch/powerpc/kernel/signal.c
View File

@ -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);

6
arch/powerpc/kernel/uprobes.c
View File

@ -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);
}
/*

54
arch/x86/kernel/uprobes.c
View File

@ -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;
}
}

10
include/linux/uprobes.h
View File

@ -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)
{

43
kernel/events/uprobes.c
View File

@ -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);

2
kernel/fork.c
View File

@ -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 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
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);

2
kernel/trace/trace_uprobe.c
View File

@ -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;
}