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authorDaniel Borkmann <daniel@iogearbox.net>2017-02-21 16:09:34 +0100
committerDavid S. Miller <davem@davemloft.net>2017-02-21 13:30:14 -0500
commit9d876e79df6a2f364b9f2737eacd72ceb27da53a (patch)
tree954aa0e71dbb2fc5fad9d6a77ca6477a873ffbe6
parentd2852a2240509e512712e25de2d0796cda435ecb (diff)
downloadlinux-9d876e79df6a2f364b9f2737eacd72ceb27da53a.tar.bz2
bpf: fix unlocking of jited image when module ronx not set
Eric and Willem reported that they recently saw random crashes when JIT was in use and bisected this to 74451e66d516 ("bpf: make jited programs visible in traces"). Issue was that the consolidation part added bpf_jit_binary_unlock_ro() that would unlock previously made read-only memory back to read-write. However, DEBUG_SET_MODULE_RONX cannot be used for this to test for presence of set_memory_*() functions. We need to use ARCH_HAS_SET_MEMORY instead to fix this; also add the corresponding bpf_jit_binary_lock_ro() to filter.h. Fixes: 74451e66d516 ("bpf: make jited programs visible in traces") Reported-by: Eric Dumazet <edumazet@google.com> Reported-by: Willem de Bruijn <willemb@google.com> Bisected-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--arch/arm64/net/bpf_jit_comp.c2
-rw-r--r--arch/s390/net/bpf_jit_comp.c2
-rw-r--r--arch/x86/net/bpf_jit_comp.c2
-rw-r--r--include/linux/filter.h13
4 files changed, 14 insertions, 5 deletions
diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
index 05d12104d270..a785554916c0 100644
--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/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;
diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index f1d0e62ec1dd..b49c52a02087 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/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;
}
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index 18a62e208826..32322ce9b405 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/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 {
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 0c1cc9143cb2..0c167fdee5f7 100644
--- a/include/linux/filter.h
+++ b/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)