From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file

---
 kernel/kernel/bpf/btf.c |   39 +++++++++++++++++++++++++--------------
 1 files changed, 25 insertions(+), 14 deletions(-)

diff --git a/kernel/kernel/bpf/btf.c b/kernel/kernel/bpf/btf.c
index 9232938..06c028b 100644
--- a/kernel/kernel/bpf/btf.c
+++ b/kernel/kernel/bpf/btf.c
@@ -604,31 +604,30 @@
 		offset < btf->hdr.str_len;
 }
 
-static bool __btf_name_char_ok(char c, bool first, bool dot_ok)
+static bool __btf_name_char_ok(char c, bool first)
 {
 	if ((first ? !isalpha(c) :
 		     !isalnum(c)) &&
 	    c != '_' &&
-	    ((c == '.' && !dot_ok) ||
-	      c != '.'))
+	    c != '.')
 		return false;
 	return true;
 }
 
-static bool __btf_name_valid(const struct btf *btf, u32 offset, bool dot_ok)
+static bool __btf_name_valid(const struct btf *btf, u32 offset)
 {
 	/* offset must be valid */
 	const char *src = &btf->strings[offset];
 	const char *src_limit;
 
-	if (!__btf_name_char_ok(*src, true, dot_ok))
+	if (!__btf_name_char_ok(*src, true))
 		return false;
 
 	/* set a limit on identifier length */
 	src_limit = src + KSYM_NAME_LEN;
 	src++;
 	while (*src && src < src_limit) {
-		if (!__btf_name_char_ok(*src, false, dot_ok))
+		if (!__btf_name_char_ok(*src, false))
 			return false;
 		src++;
 	}
@@ -636,17 +635,14 @@
 	return !*src;
 }
 
-/* Only C-style identifier is permitted. This can be relaxed if
- * necessary.
- */
 static bool btf_name_valid_identifier(const struct btf *btf, u32 offset)
 {
-	return __btf_name_valid(btf, offset, false);
+	return __btf_name_valid(btf, offset);
 }
 
 static bool btf_name_valid_section(const struct btf *btf, u32 offset)
 {
-	return __btf_name_valid(btf, offset, true);
+	return __btf_name_valid(btf, offset);
 }
 
 static const char *__btf_name_by_offset(const struct btf *btf, u32 offset)
@@ -3417,7 +3413,7 @@
 	}
 
 	if (!t->name_off ||
-	    !__btf_name_valid(env->btf, t->name_off, true)) {
+	    !__btf_name_valid(env->btf, t->name_off)) {
 		btf_verifier_log_type(env, t, "Invalid name");
 		return -EINVAL;
 	}
@@ -3541,6 +3537,7 @@
 	struct btf *btf = env->btf;
 	u16 i;
 
+	env->resolve_mode = RESOLVE_TBD;
 	for_each_vsi_from(i, v->next_member, v->t, vsi) {
 		u32 var_type_id = vsi->type, type_id, type_size = 0;
 		const struct btf_type *var_type = btf_type_by_id(env->btf,
@@ -3673,6 +3670,11 @@
 			btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
 			err = -EINVAL;
 			break;
+		}
+
+		if (btf_type_is_resolve_source_only(arg_type)) {
+			btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
+			return -EINVAL;
 		}
 
 		if (args[i].name_off &&
@@ -4268,6 +4270,7 @@
 	if (!ctx_struct)
 		/* should not happen */
 		return NULL;
+again:
 	ctx_tname = btf_name_by_offset(btf_vmlinux, ctx_struct->name_off);
 	if (!ctx_tname) {
 		/* should not happen */
@@ -4281,8 +4284,16 @@
 	 * int socket_filter_bpf_prog(struct __sk_buff *skb)
 	 * { // no fields of skb are ever used }
 	 */
-	if (strcmp(ctx_tname, tname))
-		return NULL;
+	if (strcmp(ctx_tname, tname)) {
+		/* bpf_user_pt_regs_t is a typedef, so resolve it to
+		 * underlying struct and check name again
+		 */
+		if (!btf_type_is_modifier(ctx_struct))
+			return NULL;
+		while (btf_type_is_modifier(ctx_struct))
+			ctx_struct = btf_type_by_id(btf_vmlinux, ctx_struct->type);
+		goto again;
+	}
 	return ctx_type;
 }
 

--
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