linux-stable.git/tools/lib/bpf, branch v5.8.7

libbpf: Fix map index used in error message

2020-09-03T09:29:38+00:00

[ Upstream commit 1e891e513e16c145cc9b45b1fdb8bf4a4f2f9557 ]

The error message emitted by bpf_object__init_user_btf_maps() was using the
wrong section ID.

Signed-off-by: Toke Høiland-Jørgensen 
Signed-off-by: Daniel Borkmann 
Acked-by: Yonghong Song 
Link: https://lore.kernel.org/bpf/20200819110534.9058-1-toke@redhat.com
Signed-off-by: Sasha Levin

libbpf: Prevent overriding errno when logging errors

2020-09-03T09:29:33+00:00

[ Upstream commit 23ab656be263813acc3c20623757d3cd1496d9e1 ]

Turns out there were a few more instances where libbpf didn't save the
errno before writing an error message, causing errno to be overridden by
the printf() return and the error disappearing if logging is enabled.

Signed-off-by: Toke Høiland-Jørgensen 
Signed-off-by: Daniel Borkmann 
Acked-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20200813142905.160381-1-toke@redhat.com
Signed-off-by: Sasha Levin

libbpf: Fix BTF-defined map-in-map initialization on 32-bit host arches

2020-08-26T09:49:09+00:00

[ Upstream commit 15728ad3e71c120278105f20fa65b3735e715e0f ]

Libbpf built in 32-bit mode should be careful about not conflating 64-bit BPF
pointers in BPF ELF file and host architecture pointers. This patch fixes
issue of incorrect initializating of map-in-map inner map slots due to such
difference.

Fixes: 646f02ffdd49 ("libbpf: Add BTF-defined map-in-map support")
Signed-off-by: Andrii Nakryiko 
Signed-off-by: Alexei Starovoitov 
Link: https://lore.kernel.org/bpf/20200813204945.1020225-4-andriin@fb.com
Signed-off-by: Sasha Levin

libbpf: Fix register in PT_REGS MIPS macros

2020-08-19T06:26:50+00:00

[ Upstream commit 1acf8f90ea7ee59006d0474275922145ac291331 ]

The o32, n32 and n64 calling conventions require the return
value to be stored in $v0 which maps to $2 register, i.e.,
the register 2.

Fixes: c1932cd ("bpf: Add MIPS support to samples/bpf.")
Signed-off-by: Jerry Crunchtime 
Signed-off-by: Daniel Borkmann 
Acked-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/43707d31-0210-e8f0-9226-1af140907641@web.de
Signed-off-by: Sasha Levin

libbpf: Fix libbpf hashmap on (I)LP32 architectures

2020-07-10T02:38:55+00:00

On ILP32, 64-bit result was shifted by value calculated for 32-bit long type
and returned value was much outside hashmap capacity.
As advised by Andrii Nakryiko, this patch uses different hashing variant for
architectures with size_t shorter than long long.

Fixes: e3b924224028 ("libbpf: add resizable non-thread safe internal hashmap")
Signed-off-by: Jakub Bogusz 
Signed-off-by: Andrii Nakryiko 
Signed-off-by: Alexei Starovoitov 
Link: https://lore.kernel.org/bpf/20200709225723.1069937-1-andriin@fb.com

libbpf: Adjust SEC short cut for expected attach type BPF_XDP_DEVMAP

2020-06-25T20:36:00+00:00

Adjust the SEC("xdp_devmap/") prog type prefix to contain a
slash "/" for expected attach type BPF_XDP_DEVMAP.  This is consistent
with other prog types like tracing.

Fixes: 2778797037a6 ("libbpf: Add SEC name for xdp programs attached to device map")
Suggested-by: Andrii Nakryiko 
Signed-off-by: Jesper Dangaard Brouer 
Signed-off-by: Daniel Borkmann 
Acked-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/159309521882.821855.6873145686353617509.stgit@firesoul

libbpf: Fix CO-RE relocs against .text section

2020-06-24T00:01:43+00:00

bpf_object__find_program_by_title(), used by CO-RE relocation code, doesn't
return .text "BPF program", if it is a function storage for sub-programs.
Because of that, any CO-RE relocation in helper non-inlined functions will
fail. Fix this by searching for .text-corresponding BPF program manually.

Adjust one of bpf_iter selftest to exhibit this pattern.

Fixes: ddc7c3042614 ("libbpf: implement BPF CO-RE offset relocation algorithm")
Reported-by: Yonghong Song 
Signed-off-by: Andrii Nakryiko 
Signed-off-by: Yonghong Song 
Signed-off-by: Alexei Starovoitov 
Acked-by: Yonghong Song 
Link: https://lore.kernel.org/bpf/20200619230423.691274-1-andriin@fb.com

libbpf: Forward-declare bpf_stats_type for systems with outdated UAPI headers

2020-06-22T21:23:49+00:00

Systems that doesn't yet have the very latest linux/bpf.h header, enum
bpf_stats_type will be undefined, causing compilation warnings. Prevents this
by forward-declaring enum.

Fixes: 0bee106716cf ("libbpf: Add support for command BPF_ENABLE_STATS")
Signed-off-by: Andrii Nakryiko 
Signed-off-by: Daniel Borkmann 
Acked-by: Song Liu 
Link: https://lore.kernel.org/bpf/20200621031159.2279101-1-andriin@fb.com

libbpf: Support pre-initializing .bss global variables

2020-06-12T22:27:47+00:00

Remove invalid assumption in libbpf that .bss map doesn't have to be updated
in kernel. With addition of skeleton and memory-mapped initialization image,
.bss doesn't have to be all zeroes when BPF map is created, because user-code
might have initialized those variables from user-space.

Fixes: eba9c5f498a1 ("libbpf: Refactor global data map initialization")
Signed-off-by: Andrii Nakryiko 
Signed-off-by: Alexei Starovoitov 
Link: https://lore.kernel.org/bpf/20200612194504.557844-1-andriin@fb.com

libbpf: Handle GCC noreturn-turned-volatile quirk

2020-06-10T11:37:02+00:00

Handle a GCC quirk of emitting extra volatile modifier in DWARF (and
subsequently preserved in BTF by pahole) for function pointers marked as
__attribute__((noreturn)). This was the way to mark such functions before GCC
2.5 added noreturn attribute. Drop such func_proto modifiers, similarly to how
it's done for array (also to handle GCC quirk/bug).

Such volatile attribute is emitted by GCC only, so existing selftests can't
express such test. Simple repro is like this (compiled with GCC + BTF
generated by pahole):

  struct my_struct {
      void __attribute__((noreturn)) (*fn)(int);
  };
  struct my_struct a;

Without this fix, output will be:

struct my_struct {
    voidvolatile  (*fn)(int);
};

With the fix:

struct my_struct {
    void (*fn)(int);
};

Fixes: 351131b51c7a ("libbpf: add btf_dump API for BTF-to-C conversion")
Reported-by: Jean-Philippe Brucker 
Signed-off-by: Andrii Nakryiko 
Signed-off-by: Daniel Borkmann 
Tested-by: Jean-Philippe Brucker 
Link: https://lore.kernel.org/bpf/20200610052335.2862559-1-andriin@fb.com