On Sun, Sep 25, 2022 at 07:42:48AM +0200, Martynas Pumputis wrote: > On 9/22/22 23:03, Jiri Olsa wrote: > > Changing return value of kprobe's version of bpf_get_func_ip > > to return zero if the attach address is not on the function's > > entry point. > > > > For kprobes attached in the middle of the function we can't easily > > get to the function address especially now with the CONFIG_X86_KERNEL_IBT > > support. > > > > If user cares about current IP for kprobes attached within the > > function body, they can get it with PT_REGS_IP(ctx). > > > > Suggested-by: Andrii Nakryiko <andrii@xxxxxxxxxx> > > Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx> > > Tested the patches with "pwru --filter-func='.*skb.*' > --filter-dst-ip=1.1.1.1" from [1] - the symbol name resolution works, > thanks! > > Without your patches: > > SKB CPU PROCESS FUNC > 0xffff8989c159b4e8 0 [curl] 0xffffffffbbb06164 > 0xffff8989c223f000 0 [curl] 0xffffffffbbb07534 > 0xffff8989c223f000 0 [curl] 0xffffffffbbb04934 > 0xffff8989c223f000 0 [curl] skb_release_data > 0xffff8989c223f000 0 [curl] kfree_skbmem > 0xffff8989c159b4e8 0 [curl] 0xffffffffbbb00db4 > [..] > > With patches: > > SKB CPU PROCESS FUNC > 0xffffa4564159b4e8 0 [curl] validate_xmit_skb_list > 0xffffa4564159b4e8 0 [curl] netif_skb_features > 0xffffa4564159b4e8 0 [curl] skb_network_protocol > 0xffffa4564159b4e8 0 [curl] skb_csum_hwoffload_help > 0xffffa4564159b4e8 0 [curl] skb_checksum_help > 0xffffa4564159b4e8 0 [curl] skb_ensure_writable > 0xffffa4564159b4e8 0 [curl] skb_to_sgvec > [..] > > [1]: https://github.com/cilium/pwru/tree/test-ibt-kernel-fix > > Acked-by: Martynas Pumputis <m@xxxxxxxxx> awesome, thanks jirka > > > --- > > kernel/trace/bpf_trace.c | 5 ++++- > > tools/testing/selftests/bpf/progs/get_func_ip_test.c | 4 ++-- > > 2 files changed, 6 insertions(+), 3 deletions(-) > > [..]
