[PATCH 4/8] uprobes: get rid of enum uprobe_filter_ctx in uprobe filter callbacks

From: Andrii Nakryiko
Date: Wed Jul 31 2024 - 17:44:23 EST


It serves no purpose beyond adding unnecessray argument passed to the
filter callback. Just get rid of it, no one is actually using it.

Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
---
include/linux/uprobes.h | 10 +---------
kernel/events/uprobes.c | 18 +++++++-----------
kernel/trace/bpf_trace.c | 3 +--
kernel/trace/trace_uprobe.c | 9 +++------
4 files changed, 12 insertions(+), 28 deletions(-)

diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h
index 137ddfc0b2f8..8d5bbad2048c 100644
--- a/include/linux/uprobes.h
+++ b/include/linux/uprobes.h
@@ -28,20 +28,12 @@ struct page;

#define MAX_URETPROBE_DEPTH 64

-enum uprobe_filter_ctx {
- UPROBE_FILTER_REGISTER,
- UPROBE_FILTER_UNREGISTER,
- UPROBE_FILTER_MMAP,
-};
-
struct uprobe_consumer {
int (*handler)(struct uprobe_consumer *self, struct pt_regs *regs);
int (*ret_handler)(struct uprobe_consumer *self,
unsigned long func,
struct pt_regs *regs);
- bool (*filter)(struct uprobe_consumer *self,
- enum uprobe_filter_ctx ctx,
- struct mm_struct *mm);
+ bool (*filter)(struct uprobe_consumer *self, struct mm_struct *mm);

struct uprobe_consumer *next;
};
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 6d5c3f4b210f..71a8886608b1 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -913,21 +913,19 @@ static int prepare_uprobe(struct uprobe *uprobe, struct file *file,
return ret;
}

-static inline bool consumer_filter(struct uprobe_consumer *uc,
- enum uprobe_filter_ctx ctx, struct mm_struct *mm)
+static inline bool consumer_filter(struct uprobe_consumer *uc, struct mm_struct *mm)
{
- return !uc->filter || uc->filter(uc, ctx, mm);
+ return !uc->filter || uc->filter(uc, mm);
}

-static bool filter_chain(struct uprobe *uprobe,
- enum uprobe_filter_ctx ctx, struct mm_struct *mm)
+static bool filter_chain(struct uprobe *uprobe, struct mm_struct *mm)
{
struct uprobe_consumer *uc;
bool ret = false;

down_read(&uprobe->consumer_rwsem);
for (uc = uprobe->consumers; uc; uc = uc->next) {
- ret = consumer_filter(uc, ctx, mm);
+ ret = consumer_filter(uc, mm);
if (ret)
break;
}
@@ -1094,12 +1092,10 @@ register_for_each_vma(struct uprobe *uprobe, struct uprobe_consumer *new)

if (is_register) {
/* consult only the "caller", new consumer. */
- if (consumer_filter(new,
- UPROBE_FILTER_REGISTER, mm))
+ if (consumer_filter(new, mm))
err = install_breakpoint(uprobe, mm, vma, info->vaddr);
} else if (test_bit(MMF_HAS_UPROBES, &mm->flags)) {
- if (!filter_chain(uprobe,
- UPROBE_FILTER_UNREGISTER, mm))
+ if (!filter_chain(uprobe, mm))
err |= remove_breakpoint(uprobe, mm, info->vaddr);
}

@@ -1383,7 +1379,7 @@ int uprobe_mmap(struct vm_area_struct *vma)
*/
list_for_each_entry_safe(uprobe, u, &tmp_list, pending_list) {
if (!fatal_signal_pending(current) &&
- filter_chain(uprobe, UPROBE_FILTER_MMAP, vma->vm_mm)) {
+ filter_chain(uprobe, vma->vm_mm)) {
unsigned long vaddr = offset_to_vaddr(vma, uprobe->offset);
install_breakpoint(uprobe, vma->vm_mm, vma, vaddr);
}
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 4e391daafa64..73c570b5988b 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -3320,8 +3320,7 @@ static int uprobe_prog_run(struct bpf_uprobe *uprobe,
}

static bool
-uprobe_multi_link_filter(struct uprobe_consumer *con, enum uprobe_filter_ctx ctx,
- struct mm_struct *mm)
+uprobe_multi_link_filter(struct uprobe_consumer *con, struct mm_struct *mm)
{
struct bpf_uprobe *uprobe;

diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 52e76a73fa7c..7eb79e0a5352 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -1078,9 +1078,7 @@ print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *e
return trace_handle_return(s);
}

-typedef bool (*filter_func_t)(struct uprobe_consumer *self,
- enum uprobe_filter_ctx ctx,
- struct mm_struct *mm);
+typedef bool (*filter_func_t)(struct uprobe_consumer *self, struct mm_struct *mm);

static int trace_uprobe_enable(struct trace_uprobe *tu, filter_func_t filter)
{
@@ -1339,8 +1337,7 @@ static int uprobe_perf_open(struct trace_event_call *call,
return err;
}

-static bool uprobe_perf_filter(struct uprobe_consumer *uc,
- enum uprobe_filter_ctx ctx, struct mm_struct *mm)
+static bool uprobe_perf_filter(struct uprobe_consumer *uc, struct mm_struct *mm)
{
struct trace_uprobe_filter *filter;
struct trace_uprobe *tu;
@@ -1426,7 +1423,7 @@ static void __uprobe_perf_func(struct trace_uprobe *tu,
static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs,
struct uprobe_cpu_buffer **ucbp)
{
- if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
+ if (!uprobe_perf_filter(&tu->consumer, current->mm))
return UPROBE_HANDLER_REMOVE;

if (!is_ret_probe(tu))
--
2.43.0