Daniel Borkmann 6ae08ae3de bpf: Add probe_read_{user, kernel} and probe_read_{user, kernel}_str helpers ... The current bpf_probe_read() and bpf_probe_read_str() helpers are broken in that they assume they can be used for probing memory access for kernel space addresses /as well as/ user space addresses. However, plain use of probe_kernel_read() for both cases will attempt to always access kernel space address space given access is performed under KERNEL_DS and some archs in-fact have overlapping address spaces where a kernel pointer and user pointer would have the /same/ address value and therefore accessing application memory via bpf_probe_read{,_str}() would read garbage values. Lets fix BPF side by making use of recently added 3d7081822f ("uaccess: Add non-pagefault user-space read functions"). Unfortunately, the only way to fix this status quo is to add dedicated bpf_probe_read_{user,kernel}() and bpf_probe_read_{user,kernel}_str() helpers. The bpf_probe_read{,_str}() helpers are kept as-is to retain their current behavior. The two *_user() variants attempt the access always under USER_DS set, the two *_kernel() variants will -EFAULT when accessing user memory if the underlying architecture has non-overlapping address ranges, also avoiding throwing the kernel warning via 00c42373d3 ("x86-64: add warning for non-canonical user access address dereferences"). Fixes: a5e8c07059 ("bpf: add bpf_probe_read_str helper") Fixes: 2541517c32 ("tracing, perf: Implement BPF programs attached to kprobes") 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/796ee46e948bc808d54891a1108435f8652c6ca4.1572649915.git.daniel@iogearbox.net		2019-11-02 12:39:12 -07:00
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asm-generic	mm: introduce MADV_PAGEOUT	2019-09-25 17:51:41 -07:00
drm	drm/amdgpu: return tcc_disabled_mask to userspace	2019-10-02 12:58:33 -05:00
linux	bpf: Add probe_read_{user, kernel} and probe_read_{user, kernel}_str helpers	2019-11-02 12:39:12 -07:00
misc	habanalabs: stop using the acronym KMD	2019-09-05 14:55:27 +03:00
mtd	mtd: abi: do not use C++ style comments in uapi header	2019-07-07 20:31:29 +02:00
rdma	RDMA/mlx5: RDMA_RX flow type support for user applications	2019-08-26 10:30:00 -04:00
scsi	scsi: use __u{8,16,32,64} instead of uint{8,16,32,64}_t in uapi headers	2019-08-12 22:19:27 -04:00
sound	Merge branch 'asoc-5.4' into asoc-next	2019-09-09 14:55:20 +01:00
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Kbuild	kbuild: re-implement Makefile.headersinst without recursion	2019-06-15 19:57:02 +09:00