Commit e04332eb authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Peter Zijlstra
Browse files

uprobes: kill uprobe_register_refctr() 



It doesn't make any sense to have 2 versions of _register(). Note that
trace_uprobe_enable(), the only user of uprobe_register(), doesn't need
to check tu->ref_ctr_offset to decide which one should be used, it could
safely pass ref_ctr_offset == 0 to uprobe_register_refctr().

Add this argument to uprobe_register(), update the callers, and kill
uprobe_register_refctr().

Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarJiri Olsa <jolsa@kernel.org>
Acked-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240801132728.GA8800@redhat.com
parent db61e6a4

include/linux/uprobes.h

+2 −7
Original line number Diff line number Diff line
@@ -112,8 +112,7 @@ extern bool is_trap_insn(uprobe_opcode_t *insn); 
extern unsigned long uprobe_get_swbp_addr(struct pt_regs *regs);

extern unsigned long uprobe_get_trap_addr(struct pt_regs *regs);

extern int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr, uprobe_opcode_t);

extern int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *uc);

extern int uprobe_register_refctr(struct inode *inode, loff_t offset, loff_t ref_ctr_offset, struct uprobe_consumer *uc);

extern int uprobe_register(struct inode *inode, loff_t offset, loff_t ref_ctr_offset, struct uprobe_consumer *uc);

extern int uprobe_apply(struct inode *inode, loff_t offset, struct uprobe_consumer *uc, bool);

extern void uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consumer *uc);

extern int uprobe_mmap(struct vm_area_struct *vma);
@@ -154,11 +153,7 @@ static inline void uprobes_init(void) 
#define uprobe_get_trap_addr(regs)	instruction_pointer(regs)



static inline int

uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *uc)

{

	return -ENOSYS;

}

static inline int uprobe_register_refctr(struct inode *inode, loff_t offset, loff_t ref_ctr_offset, struct uprobe_consumer *uc)

uprobe_register(struct inode *inode, loff_t offset, loff_t ref_ctr_offset, struct uprobe_consumer *uc)

{

	return -ENOSYS;

}

kernel/events/uprobes.c

+6 −18
Original line number Diff line number Diff line
@@ -1121,25 +1121,26 @@ void uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consume 
EXPORT_SYMBOL_GPL(uprobe_unregister);



/*

 * __uprobe_register - register a probe

 * uprobe_register - register a probe

 * @inode: the file in which the probe has to be placed.

 * @offset: offset from the start of the file.

 * @ref_ctr_offset: offset of SDT marker / reference counter

 * @uc: information on howto handle the probe..

 *

 * Apart from the access refcount, __uprobe_register() takes a creation

 * Apart from the access refcount, uprobe_register() takes a creation

 * refcount (thro alloc_uprobe) if and only if this @uprobe is getting

 * inserted into the rbtree (i.e first consumer for a @inode:@offset

 * tuple).  Creation refcount stops uprobe_unregister from freeing the

 * @uprobe even before the register operation is complete. Creation

 * refcount is released when the last @uc for the @uprobe

 * unregisters. Caller of __uprobe_register() is required to keep @inode

 * unregisters. Caller of uprobe_register() is required to keep @inode

 * (and the containing mount) referenced.

 *

 * Return errno if it cannot successully install probes

 * else return 0 (success)

 */

static int __uprobe_register(struct inode *inode, loff_t offset,

			     loff_t ref_ctr_offset, struct uprobe_consumer *uc)

int uprobe_register(struct inode *inode, loff_t offset, loff_t ref_ctr_offset,

		    struct uprobe_consumer *uc)

{

	struct uprobe *uprobe;

	int ret;
@@ -1189,21 +1190,8 @@ static int __uprobe_register(struct inode *inode, loff_t offset, 
		goto retry;

	return ret;

}



int uprobe_register(struct inode *inode, loff_t offset,

		    struct uprobe_consumer *uc)

{

	return __uprobe_register(inode, offset, 0, uc);

}

EXPORT_SYMBOL_GPL(uprobe_register);



int uprobe_register_refctr(struct inode *inode, loff_t offset,

			   loff_t ref_ctr_offset, struct uprobe_consumer *uc)

{

	return __uprobe_register(inode, offset, ref_ctr_offset, uc);

}

EXPORT_SYMBOL_GPL(uprobe_register_refctr);



/*

 * uprobe_apply - unregister an already registered probe.

 * @inode: the file in which the probe has to be removed.

kernel/trace/bpf_trace.c

+4 −4
Original line number Diff line number Diff line
@@ -3480,7 +3480,7 @@ int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr 
		      &bpf_uprobe_multi_link_lops, prog);



	for (i = 0; i < cnt; i++) {

		err = uprobe_register_refctr(d_real_inode(link->path.dentry),

		err = uprobe_register(d_real_inode(link->path.dentry),

				      uprobes[i].offset,

				      uprobes[i].ref_ctr_offset,

				      &uprobes[i].consumer);

kernel/trace/trace_uprobe.c

+1 −6
Original line number Diff line number Diff line
@@ -1089,12 +1089,7 @@ static int trace_uprobe_enable(struct trace_uprobe *tu, filter_func_t filter) 
	tu->consumer.filter = filter;

	tu->inode = d_real_inode(tu->path.dentry);



	if (tu->ref_ctr_offset)

		ret = uprobe_register_refctr(tu->inode, tu->offset,

				tu->ref_ctr_offset, &tu->consumer);

	else

		ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);



	ret = uprobe_register(tu->inode, tu->offset, tu->ref_ctr_offset, &tu->consumer);

	if (ret)

		tu->inode = NULL;

tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c

+2 −2
Original line number Diff line number Diff line
@@ -458,7 +458,7 @@ static int testmod_register_uprobe(loff_t offset) 
	if (err)

		goto out;



	err = uprobe_register_refctr(d_real_inode(uprobe.path.dentry),

	err = uprobe_register(d_real_inode(uprobe.path.dentry),

			      offset, 0, &uprobe.consumer);

	if (err)

		path_put(&uprobe.path);