Merge branch 'Implement formatted output helpers with bstr_printf'

Browse source

Florent Revest says:

====================

BPF's formatted output helpers are currently implemented with
snprintf-like functions which use variadic arguments. The types of all
arguments need to be known at compilation time. BPF_CAST_FMT_ARG casts
all arguments to the size they should be (known at runtime), but the C
type promotion rules cast them back to u64s. On 32 bit architectures,
this can cause misaligned va_lists and generate mangled output.

This series refactors these helpers to avoid variadic arguments. It uses
a "binary printf" instead, where arguments are passed in a buffer
constructed at runtime.
---
Changes in v2:
- Reworded the second patch's description to better describe how
  arguments get mangled on 32 bit architectures
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

...

This commit is contained in:

Alexei Starovoitov 2021-04-27 15:50:15 -07:00

parent 2551c2d19c 48cac3f4a9

commit 05eb3791a0

7 changed files with 137 additions and 132 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

18

fs/seq_file.c

View file

22

include/linux/bpf.h

View file

4

include/linux/seq_file.h

View file

1

init/Kconfig

View file

188

kernel/bpf/helpers.c

View file

2

kernel/bpf/verifier.c

View file

32

kernel/trace/bpf_trace.c

View file