Revert "tracing: Expose tracepoint BTF ids via tracefs"

This reverts commit eadc0725ab8d38c05148fce49f8d5c6a0e01f062.

ld: drivers/net/wireless/mediatek/mt76/usb_trace.o:(.bss+0x40): multiple definition of `__bpf_trace_btf_ids_dev_reg_evt'; drivers/net/wireless/mediatek/mt76/trace.o:(.bss+0x80): first defined here
ld: drivers/media/platform/nvidia/tegra-vde/vde.o:(.bss+0x180): multiple definition of `__bpf_trace_btf_ids_register_access'; drivers/gpu/drm/tegra/trace.o:(.bss+0x0): first defined here

Signed-off-by: Mark Brown <broonie@kernel.org>

2 files changed, 1 insertions, 96 deletions

diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index d3ee45af15d4..3a6308a8376f 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -23,7 +23,6 @@
 #include <linux/sort.h>
 #include <linux/slab.h>
 #include <linux/delay.h>
-#include <linux/btf.h>
 
 #include <trace/events/sched.h>
 #include <trace/syscall.h>
@@ -2227,61 +2226,6 @@ event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
 }
 #endif
 
-#ifdef CONFIG_BPF_EVENTS
-static ssize_t
-event_btf_ids_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
-{
-	struct trace_event_file *file;
-	struct trace_event_call *call;
-	const struct btf_type *t;
-	struct module *mod = NULL;
-	u32 raw_id = 0, tp_id = 0, obj_id = 0;
-	const u32 *ids;
-	struct btf *btf;
-	char buf[128];
-	int len;
-
-	/* Module unload could free call->class and ids[] mid-read. */
-	scoped_guard(mutex, &event_mutex) {
-		file = event_file_file(filp);
-		if (!file)
-			return -ENODEV;
-
-		call = file->event_call;
-		ids = call->class->btf_ids;
-		if (!ids)
-			return -ENOENT;
-		if (!(call->flags & TRACE_EVENT_FL_DYNAMIC))
-			mod = (struct module *)call->module;
-
-		btf = btf_get_module_btf(mod);
-		if (IS_ERR_OR_NULL(btf))
-			return -ENOENT;
-
-		/* Module-local ids in ids[] need base+local relocation. */
-		tp_id = btf_relocate_id(btf, ids[1]);
-
-		/*
-		 * Without FL_TRACEPOINT the dispatcher is shared (e.g. all
-		 * per-syscall events fan out from __bpf_trace_sys_enter), so
-		 * raw_btf_id has no per-event attach point — report 0.
-		 */
-		if (call->flags & TRACE_EVENT_FL_TRACEPOINT) {
-			t = btf_type_by_id(btf, btf_relocate_id(btf, ids[0]));
-			raw_id = t ? t->type : 0;
-		}
-		obj_id = btf_obj_id(btf);
-		btf_put(btf);
-	}
-
-	len = scnprintf(buf, sizeof(buf),
-			"btf_obj_id: %u\nraw_btf_id: %u\ntp_btf_id: %u\n",
-			obj_id, raw_id, tp_id);
-
-	return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
-}
-#endif
-
 static ssize_t
 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
 		  loff_t *ppos)
@@ -2782,13 +2726,6 @@ static const struct file_operations ftrace_event_id_fops = {
 };
 #endif
 
-#ifdef CONFIG_BPF_EVENTS
-static const struct file_operations ftrace_event_btf_ids_fops = {
-	.read = event_btf_ids_read,
-	.llseek = default_llseek,
-};
-#endif
-
 static const struct file_operations ftrace_event_filter_fops = {
 	.open = tracing_open_file_tr,
 	.read = event_filter_read,
@@ -3182,14 +3119,6 @@ static int event_callback(const char *name, umode_t *mode, void **data,
 	}
 #endif
 
-#ifdef CONFIG_BPF_EVENTS
-	if (call->class->btf_ids && strcmp(name, "btf_ids") == 0) {
-		*mode = TRACE_MODE_READ;
-		*fops = &ftrace_event_btf_ids_fops;
-		return 1;
-	}
-#endif
-
 #ifdef CONFIG_HIST_TRIGGERS
 	if (strcmp(name, "hist") == 0) {
 		*mode = TRACE_MODE_READ;
@@ -3244,14 +3173,7 @@ event_create_dir(struct eventfs_inode *parent, struct trace_event_file *file)
 			.callback	= event_callback,
 		},
 #endif
-#ifdef CONFIG_BPF_EVENTS
-		{
-			.name		= "btf_ids",
-			.callback	= event_callback,
-		},
-#endif
-#define NR_RO_EVENT_ENTRIES	(1 + IS_ENABLED(CONFIG_PERF_EVENTS) + \
-				 IS_ENABLED(CONFIG_BPF_EVENTS))
+#define NR_RO_EVENT_ENTRIES	(1 + IS_ENABLED(CONFIG_PERF_EVENTS))
 /* Readonly files must be above this line and counted by NR_RO_EVENT_ENTRIES. */
 		{
 			.name		= "enable",
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 48ef1a93e576..8a4f3c75e39f 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -1303,26 +1303,12 @@ struct trace_event_functions exit_syscall_print_funcs = {
 	.trace		= print_syscall_exit,
 };
 
-#ifdef CONFIG_BPF_EVENTS
-/*
- * BTF id lists generated by DECLARE_EVENT_CLASS for the sys_enter and
- * sys_exit tracepoints. The auto-generated event_class_sys_{enter,exit}
- * is unused (per-syscall events share the handcrafted classes below),
- * but the id lists themselves are global and reusable.
- */
-extern u32 __bpf_trace_btf_ids_sys_enter[];
-extern u32 __bpf_trace_btf_ids_sys_exit[];
-#endif
-
 struct trace_event_class __refdata event_class_syscall_enter = {
 	.system		= "syscalls",
 	.reg		= syscall_enter_register,
 	.fields_array	= syscall_enter_fields_array,
 	.get_fields	= syscall_get_enter_fields,
 	.raw_init	= init_syscall_trace,
-#ifdef CONFIG_BPF_EVENTS
-	.btf_ids	= __bpf_trace_btf_ids_sys_enter,
-#endif
 };
 
 struct trace_event_class __refdata event_class_syscall_exit = {
@@ -1335,9 +1321,6 @@ struct trace_event_class __refdata event_class_syscall_exit = {
 	},
 	.fields		= LIST_HEAD_INIT(event_class_syscall_exit.fields),
 	.raw_init	= init_syscall_trace,
-#ifdef CONFIG_BPF_EVENTS
-	.btf_ids	= __bpf_trace_btf_ids_sys_exit,
-#endif
 };
 
 unsigned long __init __weak arch_syscall_addr(int nr)