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authorDaniel Borkmann <daniel@iogearbox.net>2019-11-02 00:18:00 +0100
committerAlexei Starovoitov <ast@kernel.org>2019-11-02 12:39:12 -0700
commit6e07a6341277a1dbdf5ed0c41921033c234c1635 (patch)
tree439779300ddbf6452ae0a9ca1e00e6e043d2ebfb
parent6ae08ae3dea2cfa03dd3665a3c8475c2d429ef47 (diff)
downloadlinux-6e07a6341277a1dbdf5ed0c41921033c234c1635.tar.bz2
bpf: Switch BPF probe insns to bpf_probe_read_kernel
Commit 2a02759ef5f8 ("bpf: Add support for BTF pointers to interpreter") explicitly states that the pointer to BTF object is a pointer to a kernel object or NULL. Therefore we should also switch to using the strict kernel probe helper which is restricted to kernel addresses only when architectures have non-overlapping address spaces. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/d2b90827837685424a4b8008dfe0460558abfada.1572649915.git.daniel@iogearbox.net
-rw-r--r--kernel/bpf/core.c9
1 files changed, 5 insertions, 4 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 8d3fbc86ca5e..df82d5a42b23 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -1306,11 +1306,12 @@ bool bpf_opcode_in_insntable(u8 code)
}
#ifndef CONFIG_BPF_JIT_ALWAYS_ON
-u64 __weak bpf_probe_read(void * dst, u32 size, const void * unsafe_ptr)
+u64 __weak bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr)
{
memset(dst, 0, size);
return -EFAULT;
}
+
/**
* __bpf_prog_run - run eBPF program on a given context
* @regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers
@@ -1566,9 +1567,9 @@ out:
LDST(W, u32)
LDST(DW, u64)
#undef LDST
-#define LDX_PROBE(SIZEOP, SIZE) \
- LDX_PROBE_MEM_##SIZEOP: \
- bpf_probe_read(&DST, SIZE, (const void *)(long) SRC); \
+#define LDX_PROBE(SIZEOP, SIZE) \
+ LDX_PROBE_MEM_##SIZEOP: \
+ bpf_probe_read_kernel(&DST, SIZE, (const void *)(long) SRC); \
CONT;
LDX_PROBE(B, 1)
LDX_PROBE(H, 2)