linux/scripts
Yonghong Song 492e639f0c bpf: Add bpf_seq_printf and bpf_seq_write helpers
Two helpers bpf_seq_printf and bpf_seq_write, are added for
writing data to the seq_file buffer.

bpf_seq_printf supports common format string flag/width/type
fields so at least I can get identical results for
netlink and ipv6_route targets.

For bpf_seq_printf and bpf_seq_write, return value -EOVERFLOW
specifically indicates a write failure due to overflow, which
means the object will be repeated in the next bpf invocation
if object collection stays the same. Note that if the object
collection is changed, depending how collection traversal is
done, even if the object still in the collection, it may not
be visited.

For bpf_seq_printf, format %s, %p{i,I}{4,6} needs to
read kernel memory. Reading kernel memory may fail in
the following two cases:
  - invalid kernel address, or
  - valid kernel address but requiring a major fault
If reading kernel memory failed, the %s string will be
an empty string and %p{i,I}{4,6} will be all 0.
Not returning error to bpf program is consistent with
what bpf_trace_printk() does for now.

bpf_seq_printf may return -EBUSY meaning that internal percpu
buffer for memory copy of strings or other pointees is
not available. Bpf program can return 1 to indicate it
wants the same object to be repeated. Right now, this should not
happen on no-RT kernels since migrate_disable(), which guards
bpf prog call, calls preempt_disable().

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175914.2476661-1-yhs@fb.com
2020-05-09 17:05:26 -07:00
..
atomic locking/atomics: Use sed(1) instead of non-standard head(1) option 2019-06-25 10:17:07 +02:00
basic SPDX patches for 5.7-rc1. 2020-04-03 13:12:26 -07:00
coccinelle mm: remove __krealloc 2020-02-04 03:05:24 +00:00
dtc kbuild: check libyaml installation for 'make dt_binding_check' 2020-04-17 10:45:23 -05:00
dummy-tools kbuild: add dummy toolchains to enable all cc-option etc. in Kconfig 2020-04-09 00:13:45 +09:00
gcc-plugins gcc-plugins: drop support for GCC <= 4.7 2020-04-09 00:13:45 +09:00
gdb .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
genksyms .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
kconfig kconfig: qconf: Fix a few alignment issues 2020-04-09 00:13:45 +09:00
ksymoops
mod kernel/module: Hide vermagic header file from general use 2020-04-21 13:27:37 -07:00
package kbuild: deb-pkg: fix warning when CONFIG_DEBUG_INFO is unset 2020-03-30 09:23:00 +09:00
selinux SPDX patches for 5.7-rc1. 2020-04-03 13:12:26 -07:00
tracing treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 166 2019-05-30 11:26:39 -07:00
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
adjust_autoksyms.sh kbuild: split adjust_autoksyms.sh in two parts 2020-03-03 20:49:21 +09:00
asn1_compiler.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36 2019-05-24 17:27:11 +02:00
bin2c.c
bloat-o-meter bloat-o-meter: ignore __addressable_ symbols 2018-12-28 12:11:44 -08:00
bootgraph.pl treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 391 2019-06-05 17:37:11 +02:00
bpf_helpers_doc.py bpf: Add bpf_seq_printf and bpf_seq_write helpers 2020-05-09 17:05:26 -07:00
cc-can-link.sh
check_extable.sh
check-sysctl-docs docs: add a script to check sysctl docs 2020-02-25 03:35:16 -07:00
checkincludes.pl
checkkconfigsymbols.py treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 166 2019-05-30 11:26:39 -07:00
checkpatch.pl checkpatch: fix a typo in the regex for $allocFunctions 2020-04-21 11:11:55 -07:00
checkstack.pl scripts/checkstack.pl: Fix arm64 wrong or unknown architecture 2019-06-05 02:33:10 +09:00
checksyscalls.sh checksyscalls: fix up mq_timedreceive and stat exceptions 2019-02-19 21:27:53 +01:00
checkversion.pl
clang-version.sh kbuild: update comment block of scripts/clang-version.sh 2019-03-04 22:34:54 +09:00
cleanfile
cleanpatch
coccicheck
config scripts/config: allow colons in option strings for sed 2020-04-23 01:10:16 +09:00
const_structs.checkpatch
decode_stacktrace.sh scripts/decode_stacktrace: Accept dash/underscore in modules 2019-07-12 11:05:41 -07:00
decodecode scripts/decodecode: set ARCH when running natively on arm/arm64 2018-12-28 12:11:44 -08:00
depmod.sh
diffconfig
documentation-file-ref-check scripts: documentation-file-ref-check: Add line break before exit 2020-04-15 15:13:13 -06:00
export_report.pl modpost: move the namespace field in Module.symvers last 2020-03-17 08:59:03 +09:00
extract_xc3028.pl treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 339 2019-06-05 17:37:07 +02:00
extract-cert.c
extract-ikconfig
extract-module-sig.pl
extract-sys-certs.pl
extract-vmlinux treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 378 2019-06-05 17:37:10 +02:00
faddr2line
file-size.sh
find-unused-docs.sh scripts/find-unused-docs: Fix massive false positives 2020-01-27 14:25:06 -07:00
gcc-goto.sh jump_label: move 'asm goto' support test to Kconfig 2019-01-06 09:46:51 +09:00
gcc-ld
gcc-plugin.sh gcc-plugins: drop support for GCC <= 4.7 2020-04-09 00:13:45 +09:00
gcc-version.sh kbuild: clean up scripts/gcc-version.sh 2019-03-04 22:35:04 +09:00
gcc-x86_32-has-stack-protector.sh
gcc-x86_64-has-stack-protector.sh
gen_autoksyms.sh kbuild: generate autoksyms.h early 2020-03-03 20:49:21 +09:00
gen_compile_commands.py gen_compile_commands: lower the entry count threshold 2019-07-27 12:18:19 +09:00
gen_ksymdeps.sh
get_abi.pl doc: ABI scripts: add a SPDX header file 2019-06-21 16:58:37 +02:00
get_dvb_firmware treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 61 2019-05-24 17:36:45 +02:00
get_maintainer.pl scripts/get_maintainer.pl: deprioritize old Fixes: addresses 2020-02-21 11:22:15 -08:00
gfp-translate treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 166 2019-05-30 11:26:39 -07:00
headerdep.pl
headers_check.pl
headers_install.sh kbuild: re-implement detection of CONFIG options leaked to user-space 2019-08-21 21:05:21 +09:00
insert-sys-cert.c
jobserver-exec docs, parallelism: Rearrange how jobserver reservations are made 2019-11-22 10:35:18 -07:00
kallsyms.c scripts/kallsyms: fix wrong kallsyms_relative_base 2020-03-19 23:40:20 +09:00
Kbuild.include kbuild: remove *.tmp file when filechk fails 2020-01-16 00:26:22 +09:00
Kconfig.include gcc-plugins: drop support for GCC <= 4.7 2020-04-09 00:13:45 +09:00
kernel-doc scripts/kernel-doc: Add missing close-paren in c:function directives 2020-04-15 14:58:12 -06:00
ld-version.sh
leaking_addresses.pl treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 166 2019-05-30 11:26:39 -07:00
Lindent
link-vmlinux.sh bpf: Support llvm-objcopy for vmlinux BTF 2020-03-19 12:32:38 +01:00
Makefile kbuild: remove -I$(srctree)/tools/include from scripts/Makefile 2020-04-09 00:13:45 +09:00
Makefile.asm-generic kbuild: force all architectures except um to include mandatory-y 2019-03-17 12:56:32 +09:00
Makefile.build kbuild: link lib-y objects to vmlinux forcibly when CONFIG_MODULES=y 2020-04-09 00:13:45 +09:00
Makefile.clean gcc-plugins: drop support for GCC <= 4.7 2020-04-09 00:13:45 +09:00
Makefile.dtbinst kbuild: refactor Makefile.dtbinst more 2020-03-25 10:19:43 +09:00
Makefile.extrawarn kbuild: Enable -Wtautological-compare 2020-04-09 00:13:45 +09:00
Makefile.gcc-plugins gcc-plugins: structleak: Generalize to all variable types 2019-03-04 09:29:41 -08:00
Makefile.headersinst kbuild: move headers_check rule to usr/include/Makefile 2019-11-15 00:23:10 +09:00
Makefile.host gcc-plugins: drop support for GCC <= 4.7 2020-04-09 00:13:45 +09:00
Makefile.kasan kasan/arm64: fix CONFIG_KASAN_SW_TAGS && KASAN_INLINE 2019-08-15 13:24:04 +01:00
Makefile.kcov treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile.lib kbuild: fix DT binding schema rule again to avoid needless rebuilds 2020-04-23 10:50:26 +09:00
Makefile.modfinal kbuild: move modkern_{c,a}flags to Makefile.lib from Makefile.build 2019-08-22 01:14:11 +09:00
Makefile.modinst kbuild: modinst: read modules.order instead of $(MODVERDIR)/*.mod 2019-07-17 22:39:27 +09:00
Makefile.modpost modpost: return error if module is missing ns imports and MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS=n 2020-03-13 10:04:36 +09:00
Makefile.modsign kbuild: modsign: read modules.order instead of $(MODVERDIR)/*.mod 2019-07-17 22:39:27 +09:00
Makefile.package kbuild: Add make dir-pkg build option 2019-11-11 20:10:01 +09:00
Makefile.ubsan ubsan: split "bounds" checker from other options 2020-04-07 10:43:44 -07:00
makelst
markup_oops.pl treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 373 2019-06-05 17:37:10 +02:00
mkcompile_h kbuild: mkcompile_h: Include $LD version in /proc/version 2020-04-09 00:13:45 +09:00
mkmakefile kbuild: get rid of $(realpath ...) from scripts/mkmakefile 2019-08-29 23:54:29 +09:00
mksysmap
mkuboot.sh
module-common.lds
modules-check.sh kbuild: get rid of kernel/ prefix from in-tree modules.{order,builtin} 2019-07-17 22:39:27 +09:00
namespace.pl namespace: fix namespace.pl script to support relative paths 2019-10-05 15:29:49 +09:00
nsdeps scripts/nsdeps: support nsdeps for external module builds 2019-11-11 20:10:01 +09:00
objdiff treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 199 2019-05-30 11:29:23 -07:00
parse-maintainers.pl parse-maintainers: Do not sort section content by default 2020-03-26 15:08:27 -07:00
patch-kernel
profile2linkerlist.pl
prune-kernel
recordmcount.c ARM: 8950/1: ftrace/recordmcount: filter relocation types 2020-01-19 16:08:25 +00:00
recordmcount.h recordmcount: Fix nop_mcount() function 2019-10-12 20:49:33 -04:00
recordmcount.pl treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 166 2019-05-30 11:26:39 -07:00
setlocalversion scripts: setlocalversion: replace backquote to dollar parenthesis 2019-11-11 20:10:01 +09:00
show_delta treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 438 2019-06-05 17:37:17 +02:00
sign-file.c
sorttable.c scripts/sorttable: Implement build-time ORC unwind table sorting 2019-12-13 10:47:58 +01:00
sorttable.h scripts/sorttable: Implement build-time ORC unwind table sorting 2019-12-13 10:47:58 +01:00
spdxcheck-test.sh scripts: add spdxcheck.py self test 2018-12-28 12:11:44 -08:00
spdxcheck.py spdxcheck.py: fix directory structures 2019-06-01 15:51:31 -07:00
spelling.txt scripts/spelling.txt: add more spellings to spelling.txt 2020-04-02 09:35:25 -07:00
sphinx-pre-install scripts/sphinx-pre-install: add '-p python3' to virtualenv 2020-03-02 13:08:11 -07:00
split-man.pl
stackdelta
stackusage
subarch.include
tags.sh kbuild: add a flag to force absolute path for srctree 2019-07-11 00:05:09 +09:00
tools-support-relr.sh scripts/tools-support-relr.sh: un-quote variables 2019-11-13 10:52:05 +00:00
unifdef.c
ver_linux ver_linux: Query ld cache for versions of libc/libcpp run-time 2020-02-10 13:35:15 -08:00
xen-hypercalls.sh
xz_wrap.sh