The patch titled
kprobes: kretprobes simplifcations
has been added to the -mm tree. Its filename is
kprobes-kretprobes-simplifcations.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: kprobes: kretprobes simplifcations
From: Christoph Hellwig <hch@xxxxxx>
- consolidate duplicate code in all arch_prepare_kretprobe instances
into common code
- replace various odd helpers that use hlist_for_each_entry to get
the first elemenet of a list with either a hlist_for_each_entry_save
or an opencoded access to the first element in the caller
- inline add_rp_inst into it's only remaining caller
- use kretprobe_inst_table_head instead of opencoding it
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Cc: Prasanna S Panchamukhi <prasanna@xxxxxxxxxx>
Cc: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/i386/kernel/kprobes.c | 17 ++------
arch/ia64/kernel/kprobes.c | 18 ++-------
arch/powerpc/kernel/kprobes.c | 17 ++------
arch/s390/kernel/kprobes.c | 18 ++-------
arch/x86_64/kernel/kprobes.c | 17 ++------
include/linux/kprobes.h | 5 +-
kernel/kprobes.c | 64 ++++++++++----------------------
7 files changed, 43 insertions(+), 113 deletions(-)
diff -puN arch/i386/kernel/kprobes.c~kprobes-kretprobes-simplifcations arch/i386/kernel/kprobes.c
--- a/arch/i386/kernel/kprobes.c~kprobes-kretprobes-simplifcations
+++ a/arch/i386/kernel/kprobes.c
@@ -226,24 +226,15 @@ static void __kprobes prepare_singlestep
}
/* Called with kretprobe_lock held */
-void __kprobes arch_prepare_kretprobe(struct kretprobe *rp,
+void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
struct pt_regs *regs)
{
unsigned long *sara = (unsigned long *)®s->esp;
- struct kretprobe_instance *ri;
+ ri->ret_addr = (kprobe_opcode_t *) *sara;
- if ((ri = get_free_rp_inst(rp)) != NULL) {
- ri->rp = rp;
- ri->task = current;
- ri->ret_addr = (kprobe_opcode_t *) *sara;
-
- /* Replace the return addr with trampoline addr */
- *sara = (unsigned long) &kretprobe_trampoline;
- add_rp_inst(ri);
- } else {
- rp->nmissed++;
- }
+ /* Replace the return addr with trampoline addr */
+ *sara = (unsigned long) &kretprobe_trampoline;
}
/*
diff -puN arch/ia64/kernel/kprobes.c~kprobes-kretprobes-simplifcations arch/ia64/kernel/kprobes.c
--- a/arch/ia64/kernel/kprobes.c~kprobes-kretprobes-simplifcations
+++ a/arch/ia64/kernel/kprobes.c
@@ -464,23 +464,13 @@ int __kprobes trampoline_probe_handler(s
}
/* Called with kretprobe_lock held */
-void __kprobes arch_prepare_kretprobe(struct kretprobe *rp,
+void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
struct pt_regs *regs)
{
- struct kretprobe_instance *ri;
+ ri->ret_addr = (kprobe_opcode_t *)regs->b0;
- if ((ri = get_free_rp_inst(rp)) != NULL) {
- ri->rp = rp;
- ri->task = current;
- ri->ret_addr = (kprobe_opcode_t *)regs->b0;
-
- /* Replace the return addr with trampoline addr */
- regs->b0 = ((struct fnptr *)kretprobe_trampoline)->ip;
-
- add_rp_inst(ri);
- } else {
- rp->nmissed++;
- }
+ /* Replace the return addr with trampoline addr */
+ regs->b0 = ((struct fnptr *)kretprobe_trampoline)->ip;
}
int __kprobes arch_prepare_kprobe(struct kprobe *p)
diff -puN arch/powerpc/kernel/kprobes.c~kprobes-kretprobes-simplifcations arch/powerpc/kernel/kprobes.c
--- a/arch/powerpc/kernel/kprobes.c~kprobes-kretprobes-simplifcations
+++ a/arch/powerpc/kernel/kprobes.c
@@ -124,22 +124,13 @@ static void __kprobes set_current_kprobe
}
/* Called with kretprobe_lock held */
-void __kprobes arch_prepare_kretprobe(struct kretprobe *rp,
+void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
struct pt_regs *regs)
{
- struct kretprobe_instance *ri;
+ ri->ret_addr = (kprobe_opcode_t *)regs->link;
- if ((ri = get_free_rp_inst(rp)) != NULL) {
- ri->rp = rp;
- ri->task = current;
- ri->ret_addr = (kprobe_opcode_t *)regs->link;
-
- /* Replace the return addr with trampoline addr */
- regs->link = (unsigned long)kretprobe_trampoline;
- add_rp_inst(ri);
- } else {
- rp->nmissed++;
- }
+ /* Replace the return addr with trampoline addr */
+ regs->link = (unsigned long)kretprobe_trampoline;
}
static int __kprobes kprobe_handler(struct pt_regs *regs)
diff -puN arch/s390/kernel/kprobes.c~kprobes-kretprobes-simplifcations arch/s390/kernel/kprobes.c
--- a/arch/s390/kernel/kprobes.c~kprobes-kretprobes-simplifcations
+++ a/arch/s390/kernel/kprobes.c
@@ -271,23 +271,13 @@ static void __kprobes set_current_kprobe
}
/* Called with kretprobe_lock held */
-void __kprobes arch_prepare_kretprobe(struct kretprobe *rp,
+void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
struct pt_regs *regs)
{
- struct kretprobe_instance *ri;
+ ri->ret_addr = (kprobe_opcode_t *) regs->gprs[14];
- if ((ri = get_free_rp_inst(rp)) != NULL) {
- ri->rp = rp;
- ri->task = current;
- ri->ret_addr = (kprobe_opcode_t *) regs->gprs[14];
-
- /* Replace the return addr with trampoline addr */
- regs->gprs[14] = (unsigned long)&kretprobe_trampoline;
-
- add_rp_inst(ri);
- } else {
- rp->nmissed++;
- }
+ /* Replace the return addr with trampoline addr */
+ regs->gprs[14] = (unsigned long)&kretprobe_trampoline;
}
static int __kprobes kprobe_handler(struct pt_regs *regs)
diff -puN arch/x86_64/kernel/kprobes.c~kprobes-kretprobes-simplifcations arch/x86_64/kernel/kprobes.c
--- a/arch/x86_64/kernel/kprobes.c~kprobes-kretprobes-simplifcations
+++ a/arch/x86_64/kernel/kprobes.c
@@ -266,23 +266,14 @@ static void __kprobes prepare_singlestep
}
/* Called with kretprobe_lock held */
-void __kprobes arch_prepare_kretprobe(struct kretprobe *rp,
+void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
struct pt_regs *regs)
{
unsigned long *sara = (unsigned long *)regs->rsp;
- struct kretprobe_instance *ri;
- if ((ri = get_free_rp_inst(rp)) != NULL) {
- ri->rp = rp;
- ri->task = current;
- ri->ret_addr = (kprobe_opcode_t *) *sara;
-
- /* Replace the return addr with trampoline addr */
- *sara = (unsigned long) &kretprobe_trampoline;
- add_rp_inst(ri);
- } else {
- rp->nmissed++;
- }
+ ri->ret_addr = (kprobe_opcode_t *) *sara;
+ /* Replace the return addr with trampoline addr */
+ *sara = (unsigned long) &kretprobe_trampoline;
}
int __kprobes kprobe_handler(struct pt_regs *regs)
diff -puN include/linux/kprobes.h~kprobes-kretprobes-simplifcations include/linux/kprobes.h
--- a/include/linux/kprobes.h~kprobes-kretprobes-simplifcations
+++ a/include/linux/kprobes.h
@@ -123,7 +123,8 @@ DECLARE_PER_CPU(struct kprobe *, current
DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
#ifdef ARCH_SUPPORTS_KRETPROBES
-extern void arch_prepare_kretprobe(struct kretprobe *rp, struct pt_regs *regs);
+extern void arch_prepare_kretprobe(struct kretprobe_instance *ri,
+ struct pt_regs *regs);
#else /* ARCH_SUPPORTS_KRETPROBES */
static inline void arch_prepare_kretprobe(struct kretprobe *rp,
struct pt_regs *regs)
@@ -199,8 +200,6 @@ void jprobe_return(void);
int register_kretprobe(struct kretprobe *rp);
void unregister_kretprobe(struct kretprobe *rp);
-struct kretprobe_instance *get_free_rp_inst(struct kretprobe *rp);
-void add_rp_inst(struct kretprobe_instance *ri);
void kprobe_flush_task(struct task_struct *tk);
void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head);
#else /* CONFIG_KPROBES */
diff -puN kernel/kprobes.c~kprobes-kretprobes-simplifcations kernel/kprobes.c
--- a/kernel/kprobes.c~kprobes-kretprobes-simplifcations
+++ a/kernel/kprobes.c
@@ -358,46 +358,6 @@ void __kprobes kprobes_inc_nmissed_count
}
/* Called with kretprobe_lock held */
-struct kretprobe_instance __kprobes *get_free_rp_inst(struct kretprobe *rp)
-{
- struct hlist_node *node;
- struct kretprobe_instance *ri;
- hlist_for_each_entry(ri, node, &rp->free_instances, uflist)
- return ri;
- return NULL;
-}
-
-/* Called with kretprobe_lock held */
-static struct kretprobe_instance __kprobes *get_used_rp_inst(struct kretprobe
- *rp)
-{
- struct hlist_node *node;
- struct kretprobe_instance *ri;
- hlist_for_each_entry(ri, node, &rp->used_instances, uflist)
- return ri;
- return NULL;
-}
-
-/* Called with kretprobe_lock held */
-void __kprobes add_rp_inst(struct kretprobe_instance *ri)
-{
- /*
- * Remove rp inst off the free list -
- * Add it back when probed function returns
- */
- hlist_del(&ri->uflist);
-
- /* Add rp inst onto table */
- INIT_HLIST_NODE(&ri->hlist);
- hlist_add_head(&ri->hlist,
- &kretprobe_inst_table[hash_ptr(ri->task, KPROBE_HASH_BITS)]);
-
- /* Also add this rp inst to the used list. */
- INIT_HLIST_NODE(&ri->uflist);
- hlist_add_head(&ri->uflist, &ri->rp->used_instances);
-}
-
-/* Called with kretprobe_lock held */
void __kprobes recycle_rp_inst(struct kretprobe_instance *ri,
struct hlist_head *head)
{
@@ -450,7 +410,9 @@ void __kprobes kprobe_flush_task(struct
static inline void free_rp_inst(struct kretprobe *rp)
{
struct kretprobe_instance *ri;
- while ((ri = get_free_rp_inst(rp)) != NULL) {
+ struct hlist_node *pos, *next;
+
+ hlist_for_each_entry_safe(ri, pos, next, &rp->free_instances, uflist) {
hlist_del(&ri->uflist);
kfree(ri);
}
@@ -732,7 +694,21 @@ static int __kprobes pre_handler_kretpro
/*TODO: consider to only swap the RA after the last pre_handler fired */
spin_lock_irqsave(&kretprobe_lock, flags);
- arch_prepare_kretprobe(rp, regs);
+ if (!hlist_empty(&rp->free_instances)) {
+ struct kretprobe_instance *ri;
+
+ ri = hlist_entry(rp->free_instances.first,
+ struct kretprobe_instance, uflist);
+ ri->rp = rp;
+ ri->task = current;
+ arch_prepare_kretprobe(ri, regs);
+
+ /* XXX(hch): why is there no hlist_move_head? */
+ hlist_del(&ri->uflist);
+ hlist_add_head(&ri->uflist, &ri->rp->used_instances);
+ hlist_add_head(&ri->hlist, kretprobe_inst_table_head(ri->task));
+ } else
+ rp->nmissed++;
spin_unlock_irqrestore(&kretprobe_lock, flags);
return 0;
}
@@ -795,11 +771,13 @@ void __kprobes unregister_kretprobe(stru
{
unsigned long flags;
struct kretprobe_instance *ri;
+ struct hlist_node *pos, *next;
unregister_kprobe(&rp->kp);
+
/* No race here */
spin_lock_irqsave(&kretprobe_lock, flags);
- while ((ri = get_used_rp_inst(rp)) != NULL) {
+ hlist_for_each_entry_safe(ri, pos, next, &rp->used_instances, uflist) {
ri->rp = NULL;
hlist_del(&ri->uflist);
}
_
Patches currently in -mm which might be from hch@xxxxxx are
cifs-remove-unneeded-checks.patch
mm-move-common-segment-checks-to-separate-helper-function-v7.patch
mm-move-common-segment-checks-to-separate-helper-function-v7-tidy.patch
simplify-the-stacktrace-code.patch
allow-access-to-proc-pid-fd-after-setuid.patch
fix-quadratic-behavior-of-shrink_dcache_parent.patch
freevxfs-possible-null-pointer-dereference-fix.patch
vfs-remove-superflous-sb-==-null-checks.patch
nameic-remove-utterly-outdated-comment.patch
move-die-notifier-handling-to-common-code.patch
move-die-notifier-handling-to-common-code-fixes.patch
move-die-notifier-handling-to-common-code-fixes-2.patch
move-die-notifier-handling-to-common-code-fix-vmalloc_sync_all.patch
turn-do_sync_file_range-into-do_sync_mapping_range.patch
remove-do_sync_file_range.patch
make-static-counters-in-new_inode-and-iunique-be-32-bits.patch
change-libfs-sb-creation-routines-to-avoid-collisions-with-their-root-inodes.patch
aio-is-unlikely.patch
kprobes-use-hlist_for_each_entry.patch
kprobes-codingstyle-cleanups.patch
kprobes-kretprobes-simplifcations.patch
revoke-special-mmap-handling.patch
revoke-core-code.patch
revoke-support-for-ext2-and-ext3.patch
revoke-add-documentation.patch
revoke-wire-up-i386-system-calls.patch
ps3fb-thread-updates.patch
ps3av-thread-updates.patch
ps3fb-kill-superfluous-zero-initializations.patch
ps3av-misc-updates.patch
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