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
..
accounting
arch	tools headers kvm: Sync kvm headers with the kernel sources	2019-09-30 17:29:30 -03:00
bpf	Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next	2019-10-26 22:57:27 -07:00
build	tools build: Add capability-related feature detection	2019-08-12 17:14:14 -03:00
cgroup	iocost_monitor: Report debt	2019-09-10 12:31:39 -06:00
debugging
firewire
firmware
gpio
hv	- First round of vmbus hibernation support from Dexuan Cui.	2019-09-24 12:36:31 -07:00
iio	tools: iio: add .gitignore	2019-08-18 20:45:57 +01:00
include	bpf: Add probe_read_{user, kernel} and probe_read_{user, kernel}_str helpers	2019-11-02 12:39:12 -07:00
io_uring
kvm/kvm_stat
laptop
leds	leds: core: Add support for composing LED class device names	2019-07-25 20:07:52 +02:00
lib	libbpf: Add auto-pinning of maps when loading BPF objects	2019-11-02 12:35:07 -07:00
memory-model	tools/memory-model: Update the informal documentation	2019-08-09 10:28:57 -07:00
nfsd
objtool	KVM: x86: Check kvm_rebooting in kvm_spurious_fault()	2019-09-25 15:23:33 +02:00
pci
pcmcia
perf	perf annotate: Don't return -1 for error when doing BPF disassembly	2019-09-30 17:30:06 -03:00
power	platform-drivers-x86 for v5.4-2	2019-09-24 12:39:40 -07:00
scripts	perf build: Do not use -Wshadow on gcc < 4.8	2019-07-23 09:04:54 -03:00
spi
testing	selftests: Add tests for automatic map pinning	2019-11-02 12:35:07 -07:00
thermal/tmon
time
usb	usbip: tools: fix GCC8 warning for strncpy	2019-07-25 18:12:20 +02:00
virtio	tools/virtio: xen stub	2019-10-13 09:38:27 -04:00
vm
wmi
Makefile	tools: Keep list of tools in alphabetical order	2019-08-14 10:59:59 -03:00