kallsyms/bpf: Rename __bpf_address_lookup() to bpf_address_lookup()

bpf_address_lookup() has been used only in kallsyms_lookup_buildid().
It was supposed to set @modname and @modbuildid when the symbol was
in a module.

But it always just cleared @modname because BPF symbols were never in
a module. And it did not clear @modbuildid because the pointer was
not passed.

The wrapper is not longer needed. Both @modname and @modbuildid
are newly always initialized to NULL in kallsyms_lookup_buildid().

Remove the wrapper and rename __bpf_address_lookup() to
bpf_address_lookup() because this variant is used everywhere.

Fixes: 9294523 ("module: add printk formats to add module build ID to stacktraces")
Signed-off-by: Petr Mladek <[email protected]>

Author: pmladek

arch/arm64/net/bpf_jit_comp.c

@@ -2939,7 +2939,7 @@ int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type poke_type,
 	u64 plt_target = 0ULL;
 	bool poking_bpf_entry;
 
-	if (!__bpf_address_lookup((unsigned long)ip, &size, &offset, namebuf))
+	if (!bpf_address_lookup((unsigned long)ip, &size, &offset, namebuf))
 		/* Only poking bpf text is supported. Since kernel function
 		 * entry is set up by ftrace, we reply on ftrace to poke kernel
 		 * functions.

arch/powerpc/net/bpf_jit_comp.c

@@ -1122,7 +1122,7 @@ int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type poke_type,
 	branch_flags = poke_type == BPF_MOD_CALL ? BRANCH_SET_LINK : 0;
 
 	/* We currently only support poking bpf programs */
-	if (!__bpf_address_lookup(bpf_func, &size, &offset, name)) {
+	if (!bpf_address_lookup(bpf_func, &size, &offset, name)) {
 		pr_err("%s (0x%lx): kernel/modules are not supported\n", __func__, bpf_func);
 		return -EOPNOTSUPP;
 	}

include/linux/filter.h

@@ -1353,24 +1353,13 @@ static inline bool bpf_jit_kallsyms_enabled(void)
 	return false;
 }
 
-int __bpf_address_lookup(unsigned long addr, unsigned long *size,
-				 unsigned long *off, char *sym);
+int bpf_address_lookup(unsigned long addr, unsigned long *size,
+		       unsigned long *off, char *sym);
 bool is_bpf_text_address(unsigned long addr);
 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 		    char *sym);
 struct bpf_prog *bpf_prog_ksym_find(unsigned long addr);
 
-static inline int
-bpf_address_lookup(unsigned long addr, unsigned long *size,
-		   unsigned long *off, char **modname, char *sym)
-{
-	int ret = __bpf_address_lookup(addr, size, off, sym);
-
-	if (ret && modname)
-		*modname = NULL;
-	return ret;
-}
-
 void bpf_prog_kallsyms_add(struct bpf_prog *fp);
 void bpf_prog_kallsyms_del(struct bpf_prog *fp);
 
@@ -1409,8 +1398,8 @@ static inline bool bpf_jit_kallsyms_enabled(void)
 }
 
 static inline int
-__bpf_address_lookup(unsigned long addr, unsigned long *size,
-		     unsigned long *off, char *sym)
+bpf_address_lookup(unsigned long addr, unsigned long *size,
+		   unsigned long *off, char *sym)
 {
 	return 0;
 }
@@ -1431,13 +1420,6 @@ static inline struct bpf_prog *bpf_prog_ksym_find(unsigned long addr)
 	return NULL;
 }
 
-static inline int
-bpf_address_lookup(unsigned long addr, unsigned long *size,
-		   unsigned long *off, char **modname, char *sym)
-{
-	return 0;
-}
-
 static inline void bpf_prog_kallsyms_add(struct bpf_prog *fp)
 {
 }

kernel/bpf/core.c

@@ -713,8 +713,8 @@ static struct bpf_ksym *bpf_ksym_find(unsigned long addr)
 	return n ? container_of(n, struct bpf_ksym, tnode) : NULL;
 }
 
-int __bpf_address_lookup(unsigned long addr, unsigned long *size,
-				 unsigned long *off, char *sym)
+int bpf_address_lookup(unsigned long addr, unsigned long *size,
+		       unsigned long *off, char *sym)
 {
 	struct bpf_ksym *ksym;
 	int ret = 0;

kernel/kallsyms.c

@@ -342,7 +342,7 @@ int kallsyms_lookup_size_offset(unsigned long addr, unsigned long *symbolsize,
 		return 1;
 	}
 	return !!module_address_lookup(addr, symbolsize, offset, NULL, NULL, namebuf) ||
-	       !!__bpf_address_lookup(addr, symbolsize, offset, namebuf);
+	       !!bpf_address_lookup(addr, symbolsize, offset, namebuf);
 }
 
 static int kallsyms_lookup_buildid(unsigned long addr,
@@ -383,8 +383,7 @@ static int kallsyms_lookup_buildid(unsigned long addr,
 	ret = module_address_lookup(addr, symbolsize, offset,
 				    modname, modbuildid, namebuf);
 	if (!ret)
-		ret = bpf_address_lookup(addr, symbolsize,
-					 offset, modname, namebuf);
+		ret = bpf_address_lookup(addr, symbolsize, offset, namebuf);
 
 	if (!ret)
 		ret = ftrace_mod_address_lookup(addr, symbolsize,