Hello,
Test builds:
f18: http://koji.fedoraproject.org/koji/taskinfo?taskID=4635065
f17: http://koji.fedoraproject.org/koji/taskinfo?taskID=4635062
The split-out series is available in the git repository at:
http://fedorapeople.org/cgit/aarapov/public_git/kernel-uprobes.git
Just <at> jistone's patch is not upstream that exports functions.
Yes, I know it must go to upstream. :-) I will try to do what I can before
the next uprobes update.
---------------------------------------------------------------
Josh Stone (1):
uprobes: add exports necessary for uprobes use by modules
Oleg Nesterov (35):
uprobes: Kill uprobes_state->count
uprobes: Kill dup_mmap()->uprobe_mmap(), simplify uprobe_mmap/munmap
uprobes: Change uprobe_mmap() to ignore the errors but check fatal_signal_pending()
uprobes: Do not use -EEXIST in install_breakpoint() paths
uprobes: Introduce MMF_HAS_UPROBES
uprobes: Fold uprobe_reset_state() into uprobe_dup_mmap()
uprobes: Remove "verify" argument from set_orig_insn()
uprobes: uprobes_treelock should not disable irqs
uprobes: Introduce MMF_RECALC_UPROBES
uprobes: Teach find_active_uprobe() to clear MMF_HAS_UPROBES
ptrace/x86: Introduce set_task_blockstep() helper
ptrace/x86: Partly fix set_task_blockstep()->update_debugctlmsr() logic
uprobes/x86: Do not (ab)use TIF_SINGLESTEP/user_*_single_step() for single-stepping
uprobes/x86: Xol should send SIGTRAP if X86_EFLAGS_TF was set
uprobes/x86: Fix arch_uprobe_disable_step() && UTASK_SSTEP_TRAPPED interaction
uprobes: Make arch_uprobe_task->saved_trap_nr "unsigned int"
uprobes: Do not leak UTASK_BP_HIT if find_active_uprobe() fails
uprobes: Do not setup ->active_uprobe/state prematurely
uprobes: Fix UPROBE_SKIP_SSTEP checks in handle_swbp()
uprobes: Kill UTASK_BP_HIT state
uprobes: Move clear_thread_flag(TIF_UPROBE) to uprobe_notify_resume()
uprobes: Change write_opcode() to use FOLL_FORCE
uprobes: Change valid_vma() to demand VM_MAYEXEC rather than VM_EXEC
uprobes: Restrict valid_vma(false) to skip VM_SHARED vmas
uprobes: Kill set_swbp()->is_swbp_at_addr()
uprobes: Introduce copy_opcode(), kill read_opcode()
uprobes: Kill set_orig_insn()->is_swbp_at_addr()
uprobes: Simplify is_swbp_at_addr(), remove stale comments
uprobes/x86: Only rep+nop can be emulated correctly
uprobes: Don't return success if alloc_uprobe() fails
uprobes: Do not delete uprobe if uprobe_unregister() fails
uprobes: Fix handle_swbp() vs unregister() + register() race
uprobes: Introduce prepare_uprobe()
uprobes: Fix prepare_uprobe() race with itself
uprobes: Fix the racy uprobe->flags manipulation
Sebastian Andrzej Siewior (4):
uprobes: Remove check for uprobe variable in handle_swbp()
uprobes: Don't put NULL pointer in uprobe_register()
uprobes: Introduce arch_uprobe_enable/disable_step()
uprobes/x86: Implement x86 specific arch_uprobe_*_step
Srikar Dronamraju (1):
uprobes: Remove redundant lock_page/unlock_page
arch/x86/include/asm/processor.h | 2 +
arch/x86/include/asm/uprobes.h | 3 +-
arch/x86/kernel/signal.c | 4 +-
arch/x86/kernel/step.c | 53 ++--
arch/x86/kernel/uprobes.c | 64 ++++-
include/linux/sched.h | 3 +
include/linux/uprobes.h | 26 +-
kernel/events/uprobes.c | 564 ++++++++++++++++++---------------------
kernel/fork.c | 6 +-
kernel/ptrace.c | 6 +
10 files changed, 375 insertions(+), 356 deletions(-)
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index d048cad..433d2e5 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -759,6 +759,8 @@ static inline void update_debugctlmsr(unsigned long debugctlmsr)
wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctlmsr);
}
+extern void set_task_blockstep(struct task_struct *task, bool on);
+
/*
* from system description table in BIOS. Mostly for MCA use, but
* others may find it useful:
diff --git a/arch/x86/include/asm/uprobes.h b/arch/x86/include/asm/uprobes.h
index f3971bb..8ff8be7 100644
--- a/arch/x86/include/asm/uprobes.h
+++ b/arch/x86/include/asm/uprobes.h
@@ -42,10 +42,11 @@ struct arch_uprobe {
};
struct arch_uprobe_task {
- unsigned long saved_trap_nr;
#ifdef CONFIG_X86_64
unsigned long saved_scratch_register;
#endif
+ unsigned int saved_trap_nr;
+ unsigned int saved_tf;
};
extern int arch_uprobe_analyze_insn(struct arch_uprobe *aup, struct mm_struct *mm, unsigned long addr);
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index b280908..0041e5a 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -785,10 +785,8 @@ do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
mce_notify_process();
#endif /* CONFIG_X86_64 && CONFIG_X86_MCE */
- if (thread_info_flags & _TIF_UPROBE) {
- clear_thread_flag(TIF_UPROBE);
+ if (thread_info_flags & _TIF_UPROBE)
uprobe_notify_resume(regs);
- }
/* deal with pending signal delivery */
if (thread_info_flags & _TIF_SIGPENDING)
diff --git a/arch/x86/kernel/step.c b/arch/x86/kernel/step.c
index c346d11..cd3b243 100644
--- a/arch/x86/kernel/step.c
+++ b/arch/x86/kernel/step.c
@@ -157,6 +157,33 @@ static int enable_single_step(struct task_struct *child)
return 1;
}
+void set_task_blockstep(struct task_struct *task, bool on)
+{
+ unsigned long debugctl;
+
+ /*
+ * Ensure irq/preemption can't change debugctl in between.
+ * Note also that both TIF_BLOCKSTEP and debugctl should
+ * be changed atomically wrt preemption.
+ * FIXME: this means that set/clear TIF_BLOCKSTEP is simply
+ * wrong if task != current, SIGKILL can wakeup the stopped
+ * tracee and set/clear can play with the running task, this
+ * can confuse the next __switch_to_xtra().
+ */
+ local_irq_disable();
+ debugctl = get_debugctlmsr();
+ if (on) {
+ debugctl |= DEBUGCTLMSR_BTF;
+ set_tsk_thread_flag(task, TIF_BLOCKSTEP);
+ } else {
+ debugctl &= ~DEBUGCTLMSR_BTF;
+ clear_tsk_thread_flag(task, TIF_BLOCKSTEP);
+ }
+ if (task == current)
+ update_debugctlmsr(debugctl);
+ local_irq_enable();
+}
+
/*
* Enable single or block step.
*/
@@ -169,19 +196,10 @@ static void enable_step(struct task_struct *child, bool block)
* So no one should try to use debugger block stepping in a program
* that uses user-mode single stepping itself.
*/
- if (enable_single_step(child) && block) {
- unsigned long debugctl = get_debugctlmsr();
-
- debugctl |= DEBUGCTLMSR_BTF;
- update_debugctlmsr(debugctl);
- set_tsk_thread_flag(child, TIF_BLOCKSTEP);
- } else if (test_tsk_thread_flag(child, TIF_BLOCKSTEP)) {
- unsigned long debugctl = get_debugctlmsr();
-
- debugctl &= ~DEBUGCTLMSR_BTF;
- update_debugctlmsr(debugctl);
- clear_tsk_thread_flag(child, TIF_BLOCKSTEP);
- }
+ if (enable_single_step(child) && block)
+ set_task_blockstep(child, true);
+ else if (test_tsk_thread_flag(child, TIF_BLOCKSTEP))
+ set_task_blockstep(child, false);
}
void user_enable_single_step(struct task_struct *child)
@@ -199,13 +217,8 @@ void user_disable_single_step(struct task_struct *child)
/*
* Make sure block stepping (BTF) is disabled.
*/
- if (test_tsk_thread_flag(child, TIF_BLOCKSTEP)) {
- unsigned long debugctl = get_debugctlmsr();
-
- debugctl &= ~DEBUGCTLMSR_BTF;
- update_debugctlmsr(debugctl);
- clear_tsk_thread_flag(child, TIF_BLOCKSTEP);
- }
+ if (test_tsk_thread_flag(child, TIF_BLOCKSTEP))
+ set_task_blockstep(child, false);
/* Always clear TIF_SINGLESTEP... */
clear_tsk_thread_flag(child, TIF_SINGLESTEP);
diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c
index 36fd420..aafa555 100644
--- a/arch/x86/kernel/uprobes.c
+++ b/arch/x86/kernel/uprobes.c
@@ -41,6 +41,9 @@
/* Adjust the return address of a call insn */
#define UPROBE_FIX_CALL 0x2
+/* Instruction will modify TF, don't change it */
+#define UPROBE_FIX_SETF 0x4
+
#define UPROBE_FIX_RIP_AX 0x8000
#define UPROBE_FIX_RIP_CX 0x4000
@@ -239,6 +242,10 @@ static void prepare_fixups(struct arch_uprobe *auprobe, struct insn *insn)
insn_get_opcode(insn); /* should be a nop */
switch (OPCODE1(insn)) {
+ case 0x9d:
+ /* popf */
+ auprobe->fixups |= UPROBE_FIX_SETF;
+ break;
case 0xc3: /* ret/lret */
case 0xcb:
case 0xc2:
@@ -644,32 +651,63 @@ void arch_uprobe_abort_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
/*
* Skip these instructions as per the currently known x86 ISA.
- * 0x66* { 0x90 | 0x0f 0x1f | 0x0f 0x19 | 0x87 0xc0 }
+ * rep=0x66*; nop=0x90
*/
-bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs)
+static bool __skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs)
{
int i;
for (i = 0; i < MAX_UINSN_BYTES; i++) {
- if ((auprobe->insn[i] == 0x66))
+ if (auprobe->insn[i] == 0x66)
continue;
if (auprobe->insn[i] == 0x90)
return true;
- if (i == (MAX_UINSN_BYTES - 1))
- break;
+ break;
+ }
+ return false;
+}
- if ((auprobe->insn[i] == 0x0f) && (auprobe->insn[i+1] == 0x1f))
- return true;
+bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs)
+{
+ bool ret = __skip_sstep(auprobe, regs);
+ if (ret && (regs->flags & X86_EFLAGS_TF))
+ send_sig(SIGTRAP, current, 0);
+ return ret;
+}
- if ((auprobe->insn[i] == 0x0f) && (auprobe->insn[i+1] == 0x19))
- return true;
+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);
- if ((auprobe->insn[i] == 0x87) && (auprobe->insn[i+1] == 0xc0))
- return true;
+ autask->saved_tf = !!(regs->flags & X86_EFLAGS_TF);
- break;
+ 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;
}
- return false;
}
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 23bddac..ba300be 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -446,6 +446,9 @@ extern int get_dumpable(struct mm_struct *mm);
#define MMF_VM_HUGEPAGE 17 /* set when VM_HUGEPAGE is set on vma */
#define MMF_EXE_FILE_CHANGED 18 /* see prctl_set_mm_exe_file() */
+#define MMF_HAS_UPROBES 19 /* has uprobes */
+#define MMF_RECALC_UPROBES 20 /* MMF_HAS_UPROBES can be wrong */
+
#define MMF_INIT_MASK (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)
struct sighand_struct {
diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h
index efe4b33..2459457 100644
--- a/include/linux/uprobes.h
+++ b/include/linux/uprobes.h
@@ -35,16 +35,6 @@ struct inode;
# include <asm/uprobes.h>
#endif
-/* flags that denote/change uprobes behaviour */
-
-/* Have a copy of original instruction */
-#define UPROBE_COPY_INSN 0x1
-
-/* Dont run handlers when first register/ last unregister in progress*/
-#define UPROBE_RUN_HANDLER 0x2
-/* Can skip singlestep */
-#define UPROBE_SKIP_SSTEP 0x4
-
struct uprobe_consumer {
int (*handler)(struct uprobe_consumer *self, struct pt_regs *regs);
/*
@@ -59,7 +49,6 @@ struct uprobe_consumer {
#ifdef CONFIG_UPROBES
enum uprobe_task_state {
UTASK_RUNNING,
- UTASK_BP_HIT,
UTASK_SSTEP,
UTASK_SSTEP_ACK,
UTASK_SSTEP_TRAPPED,
@@ -99,25 +88,27 @@ struct xol_area {
struct uprobes_state {
struct xol_area *xol_area;
- atomic_t count;
};
+
extern int __weak set_swbp(struct arch_uprobe *aup, struct mm_struct *mm, unsigned long vaddr);
-extern int __weak set_orig_insn(struct arch_uprobe *aup, struct mm_struct *mm, unsigned long vaddr, bool verify);
+extern int __weak set_orig_insn(struct arch_uprobe *aup, struct mm_struct *mm, unsigned long vaddr);
extern bool __weak is_swbp_insn(uprobe_opcode_t *insn);
extern int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *uc);
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_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);
extern bool uprobe_deny_signal(void);
extern bool __weak arch_uprobe_skip_sstep(struct arch_uprobe *aup, struct pt_regs *regs);
extern void uprobe_clear_state(struct mm_struct *mm);
-extern void uprobe_reset_state(struct mm_struct *mm);
#else /* !CONFIG_UPROBES */
struct uprobes_state {
};
@@ -138,6 +129,10 @@ static inline void
uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned long end)
{
}
+static inline void
+uprobe_dup_mmap(struct mm_struct *oldmm, struct mm_struct *newmm)
+{
+}
static inline void uprobe_notify_resume(struct pt_regs *regs)
{
}
@@ -158,8 +153,5 @@ static inline void uprobe_copy_process(struct task_struct *t)
static inline void uprobe_clear_state(struct mm_struct *mm)
{
}
-static inline void uprobe_reset_state(struct mm_struct *mm)
-{
-}
#endif /* !CONFIG_UPROBES */
#endif /* _LINUX_UPROBES_H */
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index c08a22d..e933f65 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -27,6 +27,7 @@
#include <linux/pagemap.h> /* read_mapping_page */
#include <linux/slab.h>
#include <linux/sched.h>
+#include <linux/export.h>
#include <linux/rmap.h> /* anon_vma_prepare */
#include <linux/mmu_notifier.h> /* set_pte_at_notify */
#include <linux/swap.h> /* try_to_free_swap */
@@ -78,15 +79,23 @@ static struct mutex uprobes_mmap_mutex[UPROBES_HASH_SZ];
*/
static atomic_t uprobe_events = ATOMIC_INIT(0);
+/* Have a copy of original instruction */
+#define UPROBE_COPY_INSN 0
+/* Dont run handlers when first register/ last unregister in progress*/
+#define UPROBE_RUN_HANDLER 1
+/* Can skip singlestep */
+#define UPROBE_SKIP_SSTEP 2
+
struct uprobe {
struct rb_node rb_node; /* node in the rb tree */
atomic_t ref;
struct rw_semaphore consumer_rwsem;
+ struct mutex copy_mutex; /* TODO: kill me and UPROBE_COPY_INSN */
struct list_head pending_list;
struct uprobe_consumer *consumers;
struct inode *inode; /* Also hold a ref to inode */
loff_t offset;
- int flags;
+ unsigned long flags;
struct arch_uprobe arch;
};
@@ -100,17 +109,12 @@ struct uprobe {
*/
static bool valid_vma(struct vm_area_struct *vma, bool is_register)
{
- if (!vma->vm_file)
- return false;
+ vm_flags_t flags = VM_HUGETLB | VM_MAYEXEC | VM_SHARED;
- if (!is_register)
- return true;
+ if (is_register)
+ flags |= VM_WRITE;
- if ((vma->vm_flags & (VM_HUGETLB|VM_READ|VM_WRITE|VM_EXEC|VM_SHARED))
- == (VM_READ|VM_EXEC))
- return true;
-
- return false;
+ return vma->vm_file && (vma->vm_flags & flags) == VM_MAYEXEC;
}
static unsigned long offset_to_vaddr(struct vm_area_struct *vma, loff_t offset)
@@ -188,19 +192,44 @@ bool __weak is_swbp_insn(uprobe_opcode_t *insn)
return *insn == UPROBE_SWBP_INSN;
}
+static void copy_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t *opcode)
+{
+ void *kaddr = kmap_atomic(page);
+ memcpy(opcode, kaddr + (vaddr & ~PAGE_MASK), UPROBE_SWBP_INSN_SIZE);
+ kunmap_atomic(kaddr);
+}
+
+static int verify_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t *new_opcode)
+{
+ uprobe_opcode_t old_opcode;
+ bool is_swbp;
+
+ copy_opcode(page, vaddr, &old_opcode);
+ is_swbp = is_swbp_insn(&old_opcode);
+
+ if (is_swbp_insn(new_opcode)) {
+ if (is_swbp) /* register: already installed? */
+ return 0;
+ } else {
+ if (!is_swbp) /* unregister: was it changed by us? */
+ return 0;
+ }
+
+ return 1;
+}
+
/*
* NOTE:
* Expect the breakpoint instruction to be the smallest size instruction for
* the architecture. If an arch has variable length instruction and the
* breakpoint instruction is not of the smallest length instruction
- * supported by that architecture then we need to modify read_opcode /
+ * supported by that architecture then we need to modify is_swbp_at_addr and
* write_opcode accordingly. This would never be a problem for archs that
* have fixed length instructions.
*/
/*
* write_opcode - write the opcode at a given virtual address.
- * @auprobe: arch breakpointing information.
* @mm: the probed process address space.
* @vaddr: the virtual address to store the opcode.
* @opcode: opcode to be written at @vaddr.
@@ -211,8 +240,8 @@ bool __weak is_swbp_insn(uprobe_opcode_t *insn)
* For mm @mm, write the opcode at @vaddr.
* Return 0 (success) or a negative errno.
*/
-static int write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
- unsigned long vaddr, uprobe_opcode_t opcode)
+static int write_opcode(struct mm_struct *mm, unsigned long vaddr,
+ uprobe_opcode_t opcode)
{
struct page *old_page, *new_page;
void *vaddr_old, *vaddr_new;
@@ -221,10 +250,14 @@ static int write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
retry:
/* Read the page with vaddr into memory */
- ret = get_user_pages(NULL, mm, vaddr, 1, 0, 0, &old_page, &vma);
+ ret = get_user_pages(NULL, mm, vaddr, 1, 0, 1, &old_page, &vma);
if (ret <= 0)
return ret;
+ ret = verify_opcode(old_page, vaddr, &opcode);
+ if (ret <= 0)
+ goto put_old;
+
ret = -ENOMEM;
new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, vaddr);
if (!new_page)
@@ -259,65 +292,6 @@ static int write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
}
/**
- * read_opcode - read the opcode at a given virtual address.
- * @mm: the probed process address space.
- * @vaddr: the virtual address to read the opcode.
- * @opcode: location to store the read opcode.
- *
- * Called with mm->mmap_sem held (for read and with a reference to
- * mm.
- *
- * For mm @mm, read the opcode at @vaddr and store it in @opcode.
- * Return 0 (success) or a negative errno.
- */
-static int read_opcode(struct mm_struct *mm, unsigned long vaddr, uprobe_opcode_t *opcode)
-{
- struct page *page;
- void *vaddr_new;
- int ret;
-
- ret = get_user_pages(NULL, mm, vaddr, 1, 0, 1, &page, NULL);
- if (ret <= 0)
- return ret;
-
- lock_page(page);
- vaddr_new = kmap_atomic(page);
- vaddr &= ~PAGE_MASK;
- memcpy(opcode, vaddr_new + vaddr, UPROBE_SWBP_INSN_SIZE);
- kunmap_atomic(vaddr_new);
- unlock_page(page);
-
- put_page(page);
-
- return 0;
-}
-
-static int is_swbp_at_addr(struct mm_struct *mm, unsigned long vaddr)
-{
- uprobe_opcode_t opcode;
- int result;
-
- if (current->mm == mm) {
- pagefault_disable();
- result = __copy_from_user_inatomic(&opcode, (void __user*)vaddr,
- sizeof(opcode));
- pagefault_enable();
-
- if (likely(result == 0))
- goto out;
- }
-
- result = read_opcode(mm, vaddr, &opcode);
- if (result)
- return result;
-out:
- if (is_swbp_insn(&opcode))
- return 1;
-
- return 0;
-}
-
-/**
* set_swbp - store breakpoint at a given address.
* @auprobe: arch specific probepoint information.
* @mm: the probed process address space.
@@ -328,18 +302,7 @@ static int is_swbp_at_addr(struct mm_struct *mm, unsigned long vaddr)
*/
int __weak set_swbp(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr)
{
- int result;
- /*
- * See the comment near uprobes_hash().
- */
- result = is_swbp_at_addr(mm, vaddr);
- if (result == 1)
- return -EEXIST;
-
- if (result)
- return result;
-
- return write_opcode(auprobe, mm, vaddr, UPROBE_SWBP_INSN);
+ return write_opcode(mm, vaddr, UPROBE_SWBP_INSN);
}
/**
@@ -347,25 +310,14 @@ int __weak set_swbp(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned
* @mm: the probed process address space.
* @auprobe: arch specific probepoint information.
* @vaddr: the virtual address to insert the opcode.
- * @verify: if true, verify existance of breakpoint instruction.
*
* For mm @mm, restore the original opcode (opcode) at @vaddr.
* Return 0 (success) or a negative errno.
*/
int __weak
-set_orig_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr, bool verify)
+set_orig_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr)
{
- if (verify) {
- int result;
-
- result = is_swbp_at_addr(mm, vaddr);
- if (!result)
- return -EINVAL;
-
- if (result != 1)
- return result;
- }
- return write_opcode(auprobe, mm, vaddr, *(uprobe_opcode_t *)auprobe->insn);
+ return write_opcode(mm, vaddr, *(uprobe_opcode_t *)auprobe->insn);
}
static int match_uprobe(struct uprobe *l, struct uprobe *r)
@@ -415,11 +367,10 @@ static struct uprobe *__find_uprobe(struct inode *inode, loff_t offset)
static struct uprobe *find_uprobe(struct inode *inode, loff_t offset)
{
struct uprobe *uprobe;
- unsigned long flags;
- spin_lock_irqsave(&uprobes_treelock, flags);
+ spin_lock(&uprobes_treelock);
uprobe = __find_uprobe(inode, offset);
- spin_unlock_irqrestore(&uprobes_treelock, flags);
+ spin_unlock(&uprobes_treelock);
return uprobe;
}
@@ -466,15 +417,14 @@ static struct uprobe *__insert_uprobe(struct uprobe *uprobe)
*/
static struct uprobe *insert_uprobe(struct uprobe *uprobe)
{
- unsigned long flags;
struct uprobe *u;
- spin_lock_irqsave(&uprobes_treelock, flags);
+ spin_lock(&uprobes_treelock);
u = __insert_uprobe(uprobe);
- spin_unlock_irqrestore(&uprobes_treelock, flags);
+ spin_unlock(&uprobes_treelock);
/* For now assume that the instruction need not be single-stepped */
- uprobe->flags |= UPROBE_SKIP_SSTEP;
+ __set_bit(UPROBE_SKIP_SSTEP, &uprobe->flags);
return u;
}
@@ -496,6 +446,7 @@ static struct uprobe *alloc_uprobe(struct inode *inode, loff_t offset)
uprobe->inode = igrab(inode);
uprobe->offset = offset;
init_rwsem(&uprobe->consumer_rwsem);
+ mutex_init(&uprobe->copy_mutex);
/* add to uprobes_tree, sorted on inode:offset */
cur_uprobe = insert_uprobe(uprobe);
@@ -516,7 +467,7 @@ static void handler_chain(struct uprobe *uprobe, struct pt_regs *regs)
{
struct uprobe_consumer *uc;
- if (!(uprobe->flags & UPROBE_RUN_HANDLER))
+ if (!test_bit(UPROBE_RUN_HANDLER, &uprobe->flags))
return;
down_read(&uprobe->consumer_rwsem);
@@ -622,33 +573,48 @@ static int copy_insn(struct uprobe *uprobe, struct file *filp)
return __copy_insn(mapping, filp, uprobe->arch.insn, bytes, uprobe->offset);
}
-/*
- * How mm->uprobes_state.count gets updated
- * uprobe_mmap() increments the count if
- * - it successfully adds a breakpoint.
- * - it cannot add a breakpoint, but sees that there is a underlying
- * breakpoint (via a is_swbp_at_addr()).
- *
- * uprobe_munmap() decrements the count if
- * - it sees a underlying breakpoint, (via is_swbp_at_addr)
- * (Subsequent uprobe_unregister wouldnt find the breakpoint
- * unless a uprobe_mmap kicks in, since the old vma would be
- * dropped just after uprobe_munmap.)
- *
- * uprobe_register increments the count if:
- * - it successfully adds a breakpoint.
- *
- * uprobe_unregister decrements the count if:
- * - it sees a underlying breakpoint and removes successfully.
- * (via is_swbp_at_addr)
- * (Subsequent uprobe_munmap wouldnt find the breakpoint
- * since there is no underlying breakpoint after the
- * breakpoint removal.)
- */
+static int prepare_uprobe(struct uprobe *uprobe, struct file *file,
+ struct mm_struct *mm, unsigned long vaddr)
+{
+ int ret = 0;
+
+ if (test_bit(UPROBE_COPY_INSN, &uprobe->flags))
+ return ret;
+
+ mutex_lock(&uprobe->copy_mutex);
+ if (test_bit(UPROBE_COPY_INSN, &uprobe->flags))
+ goto out;
+
+ ret = copy_insn(uprobe, file);
+ if (ret)
+ goto out;
+
+ ret = -ENOTSUPP;
+ if (is_swbp_insn((uprobe_opcode_t *)uprobe->arch.insn))
+ goto out;
+
+ ret = arch_uprobe_analyze_insn(&uprobe->arch, mm, vaddr);
+ if (ret)
+ goto out;
+
+ /* write_opcode() assumes we don't cross page boundary */
+ BUG_ON((uprobe->offset & ~PAGE_MASK) +
+ UPROBE_SWBP_INSN_SIZE > PAGE_SIZE);
+
+ smp_wmb(); /* pairs with rmb() in find_active_uprobe() */
+ set_bit(UPROBE_COPY_INSN, &uprobe->flags);
+
+ out:
+ mutex_unlock(&uprobe->copy_mutex);
+
+ return ret;
+}
+
static int
install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm,
struct vm_area_struct *vma, unsigned long vaddr)
{
+ bool first_uprobe;
int ret;
/*
@@ -659,48 +625,38 @@ install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm,
* Hence behave as if probe already existed.
*/
if (!uprobe->consumers)
- return -EEXIST;
-
- if (!(uprobe->flags & UPROBE_COPY_INSN)) {
- ret = copy_insn(uprobe, vma->vm_file);
- if (ret)
- return ret;
-
- if (is_swbp_insn((uprobe_opcode_t *)uprobe->arch.insn))
- return -ENOTSUPP;
-
- ret = arch_uprobe_analyze_insn(&uprobe->arch, mm, vaddr);
- if (ret)
- return ret;
-
- /* write_opcode() assumes we don't cross page boundary */
- BUG_ON((uprobe->offset & ~PAGE_MASK) +
- UPROBE_SWBP_INSN_SIZE > PAGE_SIZE);
+ return 0;
- uprobe->flags |= UPROBE_COPY_INSN;
- }
+ ret = prepare_uprobe(uprobe, vma->vm_file, mm, vaddr);
+ if (ret)
+ return ret;
/*
- * Ideally, should be updating the probe count after the breakpoint
- * has been successfully inserted. However a thread could hit the
- * breakpoint we just inserted even before the probe count is
- * incremented. If this is the first breakpoint placed, breakpoint
- * notifier might ignore uprobes and pass the trap to the thread.
- * Hence increment before and decrement on failure.
+ * set MMF_HAS_UPROBES in advance for uprobe_pre_sstep_notifier(),
+ * the task can hit this breakpoint right after __replace_page().
*/
- atomic_inc(&mm->uprobes_state.count);
+ first_uprobe = !test_bit(MMF_HAS_UPROBES, &mm->flags);
+ if (first_uprobe)
+ set_bit(MMF_HAS_UPROBES, &mm->flags);
+
ret = set_swbp(&uprobe->arch, mm, vaddr);
- if (ret)
- atomic_dec(&mm->uprobes_state.count);
+ if (!ret)
+ clear_bit(MMF_RECALC_UPROBES, &mm->flags);
+ else if (first_uprobe)
+ clear_bit(MMF_HAS_UPROBES, &mm->flags);
return ret;
}
-static void
+static int
remove_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, unsigned long vaddr)
{
- if (!set_orig_insn(&uprobe->arch, mm, vaddr, true))
- atomic_dec(&mm->uprobes_state.count);
+ /* can happen if uprobe_register() fails */
+ if (!test_bit(MMF_HAS_UPROBES, &mm->flags))
+ return 0;
+
+ set_bit(MMF_RECALC_UPROBES, &mm->flags);
+ return set_orig_insn(&uprobe->arch, mm, vaddr);
}
/*
@@ -710,11 +666,9 @@ remove_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, unsigned long vad
*/
static void delete_uprobe(struct uprobe *uprobe)
{
- unsigned long flags;
-
- spin_lock_irqsave(&uprobes_treelock, flags);
+ spin_lock(&uprobes_treelock);
rb_erase(&uprobe->rb_node, &uprobes_tree);
- spin_unlock_irqrestore(&uprobes_treelock, flags);
+ spin_unlock(&uprobes_treelock);
iput(uprobe->inode);
put_uprobe(uprobe);
atomic_dec(&uprobe_events);
@@ -818,7 +772,7 @@ static int register_for_each_vma(struct uprobe *uprobe, bool is_register)
struct mm_struct *mm = info->mm;
struct vm_area_struct *vma;
- if (err)
+ if (err && is_register)
goto free;
down_write(&mm->mmap_sem);
@@ -831,17 +785,11 @@ static int register_for_each_vma(struct uprobe *uprobe, bool is_register)
vaddr_to_offset(vma, info->vaddr) != uprobe->offset)
goto unlock;
- if (is_register) {
+ if (is_register)
err = install_breakpoint(uprobe, mm, vma, info->vaddr);
- /*
- * We can race against uprobe_mmap(), see the
- * comment near uprobe_hash().
- */
- if (err == -EEXIST)
- err = 0;
- } else {
- remove_breakpoint(uprobe, mm, info->vaddr);
- }
+ else
+ err |= remove_breakpoint(uprobe, mm, info->vaddr);
+
unlock:
up_write(&mm->mmap_sem);
free:
@@ -897,21 +845,25 @@ int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *
mutex_lock(uprobes_hash(inode));
uprobe = alloc_uprobe(inode, offset);
- if (uprobe && !consumer_add(uprobe, uc)) {
+ if (!uprobe) {
+ ret = -ENOMEM;
+ } else if (!consumer_add(uprobe, uc)) {
ret = __uprobe_register(uprobe);
if (ret) {
uprobe->consumers = NULL;
__uprobe_unregister(uprobe);
} else {
- uprobe->flags |= UPROBE_RUN_HANDLER;
+ set_bit(UPROBE_RUN_HANDLER, &uprobe->flags);
}
}
mutex_unlock(uprobes_hash(inode));
- put_uprobe(uprobe);
+ if (uprobe)
+ put_uprobe(uprobe);
return ret;
}
+EXPORT_SYMBOL_GPL(uprobe_register);
/*
* uprobe_unregister - unregister a already registered probe.
@@ -935,7 +887,7 @@ void uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consume
if (consumer_del(uprobe, uc)) {
if (!uprobe->consumers) {
__uprobe_unregister(uprobe);
- uprobe->flags &= ~UPROBE_RUN_HANDLER;
+ clear_bit(UPROBE_RUN_HANDLER, &uprobe->flags);
}
}
@@ -943,6 +895,7 @@ void uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consume
if (uprobe)
put_uprobe(uprobe);
}
+EXPORT_SYMBOL_GPL(uprobe_unregister);
static struct rb_node *
find_node_in_range(struct inode *inode, loff_t min, loff_t max)
@@ -978,7 +931,6 @@ static void build_probe_list(struct inode *inode,
struct list_head *head)
{
loff_t min, max;
- unsigned long flags;
struct rb_node *n, *t;
struct uprobe *u;
@@ -986,7 +938,7 @@ static void build_probe_list(struct inode *inode,
min = vaddr_to_offset(vma, start);
max = min + (end - start) - 1;
- spin_lock_irqsave(&uprobes_treelock, flags);
+ spin_lock(&uprobes_treelock);
n = find_node_in_range(inode, min, max);
if (n) {
for (t = n; t; t = rb_prev(t)) {
@@ -1004,27 +956,20 @@ static void build_probe_list(struct inode *inode,
atomic_inc(&u->ref);
}
}
- spin_unlock_irqrestore(&uprobes_treelock, flags);
+ spin_unlock(&uprobes_treelock);
}
/*
- * Called from mmap_region.
- * called with mm->mmap_sem acquired.
- *
- * Return -ve no if we fail to insert probes and we cannot
- * bail-out.
- * Return 0 otherwise. i.e:
+ * Called from mmap_region/vma_adjust with mm->mmap_sem acquired.
*
- * - successful insertion of probes
- * - (or) no possible probes to be inserted.
- * - (or) insertion of probes failed but we can bail-out.
+ * Currently we ignore all errors and always return 0, the callers
+ * can't handle the failure anyway.
*/
int uprobe_mmap(struct vm_area_struct *vma)
{
struct list_head tmp_list;
struct uprobe *uprobe, *u;
struct inode *inode;
- int ret, count;
if (!atomic_read(&uprobe_events) || !valid_vma(vma, true))
return 0;
@@ -1036,44 +981,35 @@ int uprobe_mmap(struct vm_area_struct *vma)
mutex_lock(uprobes_mmap_hash(inode));
build_probe_list(inode, vma, vma->vm_start, vma->vm_end, &tmp_list);
- ret = 0;
- count = 0;
-
list_for_each_entry_safe(uprobe, u, &tmp_list, pending_list) {
- if (!ret) {
+ if (!fatal_signal_pending(current)) {
unsigned long vaddr = offset_to_vaddr(vma, uprobe->offset);
-
- ret = install_breakpoint(uprobe, vma->vm_mm, vma, vaddr);
- /*
- * We can race against uprobe_register(), see the
- * comment near uprobe_hash().
- */
- if (ret == -EEXIST) {
- ret = 0;
-
- if (!is_swbp_at_addr(vma->vm_mm, vaddr))
- continue;
-
- /*
- * Unable to insert a breakpoint, but
- * breakpoint lies underneath. Increment the
- * probe count.
- */
- atomic_inc(&vma->vm_mm->uprobes_state.count);
- }
-
- if (!ret)
- count++;
+ install_breakpoint(uprobe, vma->vm_mm, vma, vaddr);
}
put_uprobe(uprobe);
}
-
mutex_unlock(uprobes_mmap_hash(inode));
- if (ret)
- atomic_sub(count, &vma->vm_mm->uprobes_state.count);
+ return 0;
+}
- return ret;
+static bool
+vma_has_uprobes(struct vm_area_struct *vma, unsigned long start, unsigned long end)
+{
+ loff_t min, max;
+ struct inode *inode;
+ struct rb_node *n;
+
+ inode = vma->vm_file->f_mapping->host;
+
+ min = vaddr_to_offset(vma, start);
+ max = min + (end - start) - 1;
+
+ spin_lock(&uprobes_treelock);
+ n = find_node_in_range(inode, min, max);
+ spin_unlock(&uprobes_treelock);
+
+ return !!n;
}
/*
@@ -1081,37 +1017,18 @@ int uprobe_mmap(struct vm_area_struct *vma)
*/
void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned long end)
{
- struct list_head tmp_list;
- struct uprobe *uprobe, *u;
- struct inode *inode;
-
if (!atomic_read(&uprobe_events) || !valid_vma(vma, false))
return;
if (!atomic_read(&vma->vm_mm->mm_users)) /* called by mmput() ? */
return;
- if (!atomic_read(&vma->vm_mm->uprobes_state.count))
- return;
-
- inode = vma->vm_file->f_mapping->host;
- if (!inode)
+ if (!test_bit(MMF_HAS_UPROBES, &vma->vm_mm->flags) ||
+ test_bit(MMF_RECALC_UPROBES, &vma->vm_mm->flags))
return;
- mutex_lock(uprobes_mmap_hash(inode));
- build_probe_list(inode, vma, start, end, &tmp_list);
-
- list_for_each_entry_safe(uprobe, u, &tmp_list, pending_list) {
- unsigned long vaddr = offset_to_vaddr(vma, uprobe->offset);
- /*
- * An unregister could have removed the probe before
- * unmap. So check before we decrement the count.
- */
- if (is_swbp_at_addr(vma->vm_mm, vaddr) == 1)
- atomic_dec(&vma->vm_mm->uprobes_state.count);
- put_uprobe(uprobe);
- }
- mutex_unlock(uprobes_mmap_hash(inode));
+ if (vma_has_uprobes(vma, start, end))
+ set_bit(MMF_RECALC_UPROBES, &vma->vm_mm->flags);
}
/* Slot allocation for XOL */
@@ -1213,13 +1130,15 @@ void uprobe_clear_state(struct mm_struct *mm)
kfree(area);
}
-/*
- * uprobe_reset_state - Free the area allocated for slots.
- */
-void uprobe_reset_state(struct mm_struct *mm)
+void uprobe_dup_mmap(struct mm_struct *oldmm, struct mm_struct *newmm)
{
- mm->uprobes_state.xol_area = NULL;
- atomic_set(&mm->uprobes_state.count, 0);
+ newmm->uprobes_state.xol_area = NULL;
+
+ if (test_bit(MMF_HAS_UPROBES, &oldmm->flags)) {
+ set_bit(MMF_HAS_UPROBES, &newmm->flags);
+ /* unconditionally, dup_mmap() skips VM_DONTCOPY vmas */
+ set_bit(MMF_RECALC_UPROBES, &newmm->flags);
+ }
}
/*
@@ -1430,13 +1349,57 @@ bool uprobe_deny_signal(void)
*/
static bool can_skip_sstep(struct uprobe *uprobe, struct pt_regs *regs)
{
- if (arch_uprobe_skip_sstep(&uprobe->arch, regs))
- return true;
-
- uprobe->flags &= ~UPROBE_SKIP_SSTEP;
+ if (test_bit(UPROBE_SKIP_SSTEP, &uprobe->flags)) {
+ if (arch_uprobe_skip_sstep(&uprobe->arch, regs))
+ return true;
+ clear_bit(UPROBE_SKIP_SSTEP, &uprobe->flags);
+ }
return false;
}
+static void mmf_recalc_uprobes(struct mm_struct *mm)
+{
+ struct vm_area_struct *vma;
+
+ for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ if (!valid_vma(vma, false))
+ continue;
+ /*
+ * This is not strictly accurate, we can race with
+ * uprobe_unregister() and see the already removed
+ * uprobe if delete_uprobe() was not yet called.
+ */
+ if (vma_has_uprobes(vma, vma->vm_start, vma->vm_end))
+ return;
+ }
+
+ clear_bit(MMF_HAS_UPROBES, &mm->flags);
+}
+
+static int is_swbp_at_addr(struct mm_struct *mm, unsigned long vaddr)
+{
+ struct page *page;
+ uprobe_opcode_t opcode;
+ int result;
+
+ pagefault_disable();
+ result = __copy_from_user_inatomic(&opcode, (void __user*)vaddr,
+ sizeof(opcode));
+ pagefault_enable();
+
+ if (likely(result == 0))
+ goto out;
+
+ result = get_user_pages(NULL, mm, vaddr, 1, 0, 1, &page, NULL);
+ if (result < 0)
+ return result;
+
+ copy_opcode(page, vaddr, &opcode);
+ put_page(page);
+ out:
+ return is_swbp_insn(&opcode);
+}
+
static struct uprobe *find_active_uprobe(unsigned long bp_vaddr, int *is_swbp)
{
struct mm_struct *mm = current->mm;
@@ -1458,11 +1421,24 @@ static struct uprobe *find_active_uprobe(unsigned long bp_vaddr, int *is_swbp)
} else {
*is_swbp = -EFAULT;
}
+
+ if (!uprobe && test_and_clear_bit(MMF_RECALC_UPROBES, &mm->flags))
+ mmf_recalc_uprobes(mm);
up_read(&mm->mmap_sem);
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.
@@ -1494,41 +1470,42 @@ static void handle_swbp(struct pt_regs *regs)
}
return;
}
+ /*
+ * TODO: move copy_insn/etc into _register and remove this hack.
+ * After we hit the bp, _unregister + _register can install the
+ * new and not-yet-analyzed uprobe at the same address, restart.
+ */
+ smp_rmb(); /* pairs with wmb() in install_breakpoint() */
+ if (unlikely(!test_bit(UPROBE_COPY_INSN, &uprobe->flags)))
+ goto restart;
utask = current->utask;
if (!utask) {
utask = add_utask();
/* Cannot allocate; re-execute the instruction. */
if (!utask)
- goto cleanup_ret;
+ goto restart;
}
- utask->active_uprobe = uprobe;
+
handler_chain(uprobe, regs);
- if (uprobe->flags & UPROBE_SKIP_SSTEP && can_skip_sstep(uprobe, regs))
- goto cleanup_ret;
+ if (can_skip_sstep(uprobe, regs))
+ goto out;
- utask->state = UTASK_SSTEP;
if (!pre_ssout(uprobe, regs, bp_vaddr)) {
- user_enable_single_step(current);
+ arch_uprobe_enable_step(&uprobe->arch);
+ utask->active_uprobe = uprobe;
+ utask->state = UTASK_SSTEP;
return;
}
-cleanup_ret:
- if (utask) {
- utask->active_uprobe = NULL;
- utask->state = UTASK_RUNNING;
- }
- if (uprobe) {
- if (!(uprobe->flags & UPROBE_SKIP_SSTEP))
-
- /*
- * cannot singlestep; cannot skip instruction;
- * re-execute the instruction.
- */
- instruction_pointer_set(regs, bp_vaddr);
-
- put_uprobe(uprobe);
- }
+restart:
+ /*
+ * cannot singlestep; cannot skip instruction;
+ * re-execute the instruction.
+ */
+ instruction_pointer_set(regs, bp_vaddr);
+out:
+ put_uprobe(uprobe);
}
/*
@@ -1547,10 +1524,10 @@ 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;
- user_disable_single_step(current);
xol_free_insn_slot(current);
spin_lock_irq(¤t->sighand->siglock);
@@ -1559,13 +1536,12 @@ static void handle_singlestep(struct uprobe_task *utask, struct pt_regs *regs)
}
/*
- * On breakpoint hit, breakpoint notifier sets the TIF_UPROBE flag. (and on
- * subsequent probe hits on the thread sets the state to UTASK_BP_HIT) and
- * allows the thread to return from interrupt.
+ * On breakpoint hit, breakpoint notifier sets the TIF_UPROBE flag and
+ * allows the thread to return from interrupt. After that handle_swbp()
+ * sets utask->active_uprobe.
*
- * On singlestep exception, singlestep notifier sets the TIF_UPROBE flag and
- * also sets the state to UTASK_SSTEP_ACK and allows the thread to return from
- * interrupt.
+ * On singlestep exception, singlestep notifier sets the TIF_UPROBE flag
+ * and allows the thread to return from interrupt.
*
* While returning to userspace, thread notices the TIF_UPROBE flag and calls
* uprobe_notify_resume().
@@ -1574,11 +1550,13 @@ void uprobe_notify_resume(struct pt_regs *regs)
{
struct uprobe_task *utask;
+ clear_thread_flag(TIF_UPROBE);
+
utask = current->utask;
- if (!utask || utask->state == UTASK_BP_HIT)
- handle_swbp(regs);
- else
+ if (utask && utask->active_uprobe)
handle_singlestep(utask, regs);
+ else
+ handle_swbp(regs);
}
/*
@@ -1587,18 +1565,10 @@ void uprobe_notify_resume(struct pt_regs *regs)
*/
int uprobe_pre_sstep_notifier(struct pt_regs *regs)
{
- struct uprobe_task *utask;
-
- if (!current->mm || !atomic_read(¤t->mm->uprobes_state.count))
- /* task is currently not uprobed */
+ if (!current->mm || !test_bit(MMF_HAS_UPROBES, ¤t->mm->flags))
return 0;
- utask = current->utask;
- if (utask)
- utask->state = UTASK_BP_HIT;
-
set_thread_flag(TIF_UPROBE);
-
return 1;
}
diff --git a/kernel/fork.c b/kernel/fork.c
index 2c8857e..2343c9e 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -353,6 +353,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
down_write(&oldmm->mmap_sem);
flush_cache_dup_mm(oldmm);
+ uprobe_dup_mmap(oldmm, mm);
/*
* Not linked in yet - no deadlock potential:
*/
@@ -454,9 +455,6 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
if (retval)
goto out;
-
- if (file)
- uprobe_mmap(tmp);
}
/* a new mm has just been created */
arch_dup_mmap(oldmm, mm);
@@ -839,8 +837,6 @@ struct mm_struct *dup_mm(struct task_struct *tsk)
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
mm->pmd_huge_pte = NULL;
#endif
- uprobe_reset_state(mm);
-
if (!mm_init(mm, tsk))
goto fail_nomem;
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index a232bb5..764fcd1 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -33,6 +33,12 @@ static int ptrace_trapping_sleep_fn(void *flags)
}
/*
+ * This is declared in linux/regset.h and defined in machine-dependent
+ * code. We put the export here to ensure no machine forgets it.
+ */
+EXPORT_SYMBOL_GPL(task_user_regset_view);
+
+/*
* ptrace a task: make the debugger its new parent and
* move it to the ptrace list.
*
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