1 files changed, 130 insertions, 7 deletions

diff --git a/include/linux/filter.h b/include/linux/filter.h
index e4eb2546339a..fbf7b39e8103 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -54,6 +54,12 @@ struct bpf_prog_aux;
 #define BPF_REG_AX		MAX_BPF_REG
 #define MAX_BPF_JIT_REG		(MAX_BPF_REG + 1)
 
+/* As per nm, we expose JITed images as text (code) section for
+ * kallsyms. That way, tools like perf can find it to match
+ * addresses.
+ */
+#define BPF_SYM_ELF_TYPE	't'
+
 /* BPF program can access up to 512 bytes of stack space. */
 #define MAX_BPF_STACK	512
 
@@ -403,6 +409,7 @@ struct bpf_prog {
 	u16			pages;		/* Number of allocated pages */
 	kmemcheck_bitfield_begin(meta);
 	u16			jited:1,	/* Is our filter JIT'ed? */
+				locked:1,	/* Program image locked? */
 				gpl_compatible:1, /* Is filter GPL compatible? */
 				cb_access:1,	/* Is control block accessed? */
 				dst_needed:1,	/* Do we need dst entry? */
@@ -545,15 +552,32 @@ static inline bool bpf_prog_was_classic(const struct bpf_prog *prog)
 
 #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0]))
 
-#ifdef CONFIG_DEBUG_SET_MODULE_RONX
+#ifdef CONFIG_ARCH_HAS_SET_MEMORY
 static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
 {
-	set_memory_ro((unsigned long)fp, fp->pages);
+	fp->locked = 1;
+	WARN_ON_ONCE(set_memory_ro((unsigned long)fp, fp->pages));
 }
 
 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
 {
-	set_memory_rw((unsigned long)fp, fp->pages);
+	if (fp->locked) {
+		WARN_ON_ONCE(set_memory_rw((unsigned long)fp, fp->pages));
+		/* In case set_memory_rw() fails, we want to be the first
+		 * to crash here instead of some random place later on.
+		 */
+		fp->locked = 0;
+	}
+}
+
+static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
+{
+	WARN_ON_ONCE(set_memory_ro((unsigned long)hdr, hdr->pages));
+}
+
+static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr)
+{
+	WARN_ON_ONCE(set_memory_rw((unsigned long)hdr, hdr->pages));
 }
 #else
 static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
@@ -563,7 +587,24 @@ static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
 {
 }
-#endif /* CONFIG_DEBUG_SET_MODULE_RONX */
+
+static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
+{
+}
+
+static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr)
+{
+}
+#endif /* CONFIG_ARCH_HAS_SET_MEMORY */
+
+static inline struct bpf_binary_header *
+bpf_jit_binary_hdr(const struct bpf_prog *fp)
+{
+	unsigned long real_start = (unsigned long)fp->bpf_func;
+	unsigned long addr = real_start & PAGE_MASK;
+
+	return (void *)addr;
+}
 
 int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap);
 static inline int sk_filter(struct sock *sk, struct sk_buff *skb)
@@ -607,6 +648,7 @@ void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);
 u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
 
 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog);
+void bpf_jit_compile(struct bpf_prog *prog);
 bool bpf_helper_changes_pkt_data(void *func);
 
 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
@@ -616,6 +658,7 @@ void bpf_warn_invalid_xdp_action(u32 act);
 #ifdef CONFIG_BPF_JIT
 extern int bpf_jit_enable;
 extern int bpf_jit_harden;
+extern int bpf_jit_kallsyms;
 
 typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size);
 
@@ -625,7 +668,6 @@ bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
 		     bpf_jit_fill_hole_t bpf_fill_ill_insns);
 void bpf_jit_binary_free(struct bpf_binary_header *hdr);
 
-void bpf_jit_compile(struct bpf_prog *fp);
 void bpf_jit_free(struct bpf_prog *fp);
 
 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *fp);
@@ -651,6 +693,11 @@ static inline bool bpf_jit_is_ebpf(void)
 # endif
 }
 
+static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
+{
+	return fp->jited && bpf_jit_is_ebpf();
+}
+
 static inline bool bpf_jit_blinding_enabled(void)
 {
 	/* These are the prerequisites, should someone ever have the
@@ -668,15 +715,91 @@ static inline bool bpf_jit_blinding_enabled(void)
 
 	return true;
 }
-#else
-static inline void bpf_jit_compile(struct bpf_prog *fp)
+
+static inline bool bpf_jit_kallsyms_enabled(void)
+{
+	/* There are a couple of corner cases where kallsyms should
+	 * not be enabled f.e. on hardening.
+	 */
+	if (bpf_jit_harden)
+		return false;
+	if (!bpf_jit_kallsyms)
+		return false;
+	if (bpf_jit_kallsyms == 1)
+		return true;
+
+	return false;
+}
+
+const char *__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);
+
+static inline const char *
+bpf_address_lookup(unsigned long addr, unsigned long *size,
+		   unsigned long *off, char **modname, char *sym)
+{
+	const char *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);
+
+#else /* CONFIG_BPF_JIT */
+
+static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
 {
+	return false;
 }
 
 static inline void bpf_jit_free(struct bpf_prog *fp)
 {
 	bpf_prog_unlock_free(fp);
 }
+
+static inline bool bpf_jit_kallsyms_enabled(void)
+{
+	return false;
+}
+
+static inline const char *
+__bpf_address_lookup(unsigned long addr, unsigned long *size,
+		     unsigned long *off, char *sym)
+{
+	return NULL;
+}
+
+static inline bool is_bpf_text_address(unsigned long addr)
+{
+	return false;
+}
+
+static inline int bpf_get_kallsym(unsigned int symnum, unsigned long *value,
+				  char *type, char *sym)
+{
+	return -ERANGE;
+}
+
+static inline const char *
+bpf_address_lookup(unsigned long addr, unsigned long *size,
+		   unsigned long *off, char **modname, char *sym)
+{
+	return NULL;
+}
+
+static inline void bpf_prog_kallsyms_add(struct bpf_prog *fp)
+{
+}
+
+static inline void bpf_prog_kallsyms_del(struct bpf_prog *fp)
+{
+}
 #endif /* CONFIG_BPF_JIT */
 
 #define BPF_ANC		BIT(15)