Merge branch 'bpf-unlocking-fix'

Daniel Borkmann says:

====================
BPF fix with regards to unlocking

This set fixes the issue Eric was reporting recently [1].
First patch is a prerequisite discussed with Laura that is
needed for the later fix in the second one. I've tested this
extensively and it does not reproduce anymore on my side
after the fix. Thanks & sorry about that!

  [1] https://www.spinics.net/lists/netdev/msg421877.html
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

arch/Kconfig

@@ -222,6 +222,10 @@ config GENERIC_SMP_IDLE_THREAD
 config GENERIC_IDLE_POLL_SETUP
        bool
 
+# Select if arch has all set_memory_ro/rw/x/nx() functions in asm/cacheflush.h
+config ARCH_HAS_SET_MEMORY
+	bool
+
 # Select if arch init_task initializer is different to init/init_task.c
 config ARCH_INIT_TASK
        bool

arch/arm/Kconfig

@@ -4,6 +4,7 @@ config ARM
 	select ARCH_CLOCKSOURCE_DATA
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_ELF_RANDOMIZE
+	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
 	select ARCH_HAVE_CUSTOM_GPIO_H
 	select ARCH_HAS_GCOV_PROFILE_ALL

arch/arm64/Kconfig

@@ -12,6 +12,7 @@ config ARM64
 	select ARCH_HAS_GCOV_PROFILE_ALL
 	select ARCH_HAS_GIGANTIC_PAGE
 	select ARCH_HAS_KCOV
+	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_SG_CHAIN
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
 	select ARCH_USE_CMPXCHG_LOCKREF

arch/arm64/net/bpf_jit_comp.c

@@ -898,7 +898,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
 
 	bpf_flush_icache(header, ctx.image + ctx.idx);
 
-	set_memory_ro((unsigned long)header, header->pages);
+	bpf_jit_binary_lock_ro(header);
 	prog->bpf_func = (void *)ctx.image;
 	prog->jited = 1;
 

arch/s390/Kconfig

@@ -72,6 +72,7 @@ config S390
 	select ARCH_HAS_GCOV_PROFILE_ALL
 	select ARCH_HAS_GIGANTIC_PAGE
 	select ARCH_HAS_KCOV
+	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_SG_CHAIN
 	select ARCH_HAS_UBSAN_SANITIZE_ALL
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG

arch/s390/net/bpf_jit_comp.c

@@ -1327,7 +1327,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
 			print_fn_code(jit.prg_buf, jit.size_prg);
 	}
 	if (jit.prg_buf) {
-		set_memory_ro((unsigned long)header, header->pages);
+		bpf_jit_binary_lock_ro(header);
 		fp->bpf_func = (void *) jit.prg_buf;
 		fp->jited = 1;
 	}

arch/x86/Kconfig

@@ -53,6 +53,7 @@ config X86
 	select ARCH_HAS_KCOV			if X86_64
 	select ARCH_HAS_MMIO_FLUSH
 	select ARCH_HAS_PMEM_API		if X86_64
+	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_SG_CHAIN
 	select ARCH_HAS_UBSAN_SANITIZE_ALL
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG

arch/x86/net/bpf_jit_comp.c

@@ -1165,7 +1165,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
 
 	if (image) {
 		bpf_flush_icache(header, image + proglen);
-		set_memory_ro((unsigned long)header, header->pages);
+		bpf_jit_binary_lock_ro(header);
 		prog->bpf_func = (void *)image;
 		prog->jited = 1;
 	} else {

include/linux/filter.h

@@ -551,7 +551,7 @@ 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);
@@ -562,6 +562,11 @@ static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
 	set_memory_rw((unsigned long)fp, fp->pages);
 }
 
+static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
+{
+	set_memory_ro((unsigned long)hdr, hdr->pages);
+}
+
 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr)
 {
 	set_memory_rw((unsigned long)hdr, hdr->pages);
@@ -575,10 +580,14 @@ static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
 {
 }
 
+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_DEBUG_SET_MODULE_RONX */
+#endif /* CONFIG_ARCH_HAS_SET_MEMORY */
 
 static inline struct bpf_binary_header *
 bpf_jit_binary_hdr(const struct bpf_prog *fp)