| Message ID | 20220328175033.2437312-15-roberto.sassu@huawei.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | bpf: Secure and authenticated preloading of eBPF programs | expand |
Hi Roberto,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on bpf-next/master]
[also build test ERROR on linus/master next-20220328]
[cannot apply to bpf/master v5.17]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/intel-lab-lkp/linux/commits/Roberto-Sassu/bpf-Secure-and-authenticated-preloading-of-eBPF-programs/20220329-015829
base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
config: i386-randconfig-c001 (https://download.01.org/0day-ci/archive/20220329/202203291042.8dll5BFm-lkp@intel.com/config)
compiler: gcc-9 (Ubuntu 9.4.0-1ubuntu1~20.04.1) 9.4.0
reproduce (this is a W=1 build):
# https://github.com/intel-lab-lkp/linux/commit/2e0e81b0296abc384efb2a73520ce03c2a5344ea
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Roberto-Sassu/bpf-Secure-and-authenticated-preloading-of-eBPF-programs/20220329-015829
git checkout 2e0e81b0296abc384efb2a73520ce03c2a5344ea
# save the config file to linux build tree
mkdir build_dir
make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
>> kernel/bpf/inode.c:25:37: error: 'CONFIG_BPF_PRELOAD_LIST' undeclared here (not in a function)
25 | static char *bpf_preload_list_str = CONFIG_BPF_PRELOAD_LIST;
| ^~~~~~~~~~~~~~~~~~~~~~~
vim +/CONFIG_BPF_PRELOAD_LIST +25 kernel/bpf/inode.c
24
> 25 static char *bpf_preload_list_str = CONFIG_BPF_PRELOAD_LIST;
26
Hi Roberto,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on bpf-next/master]
[also build test ERROR on bpf/master linus/master next-20220328]
[cannot apply to v5.17]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/intel-lab-lkp/linux/commits/Roberto-Sassu/bpf-Secure-and-authenticated-preloading-of-eBPF-programs/20220329-015829
base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
config: arm64-randconfig-r026-20220328 (https://download.01.org/0day-ci/archive/20220329/202203291125.8NpccWn1-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 0f6d9501cf49ce02937099350d08f20c4af86f3d)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install arm64 cross compiling tool for clang build
# apt-get install binutils-aarch64-linux-gnu
# https://github.com/intel-lab-lkp/linux/commit/2e0e81b0296abc384efb2a73520ce03c2a5344ea
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Roberto-Sassu/bpf-Secure-and-authenticated-preloading-of-eBPF-programs/20220329-015829
git checkout 2e0e81b0296abc384efb2a73520ce03c2a5344ea
# save the config file to linux build tree
mkdir build_dir
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm64 SHELL=/bin/bash
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
>> kernel/bpf/inode.c:25:37: error: use of undeclared identifier 'CONFIG_BPF_PRELOAD_LIST'
static char *bpf_preload_list_str = CONFIG_BPF_PRELOAD_LIST;
^
1 error generated.
vim +/CONFIG_BPF_PRELOAD_LIST +25 kernel/bpf/inode.c
24
> 25 static char *bpf_preload_list_str = CONFIG_BPF_PRELOAD_LIST;
26
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 9927564db88e..732d83764e6e 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -482,6 +482,14 @@ bgrt_disable [ACPI][X86] Disable BGRT to avoid flickering OEM logo. + bpf_preload_list= [BPF] + Specify a list of eBPF programs to preload. + Format: obj_name1,obj_name2,... + Default: bpf_preload + + Specify the list of eBPF programs to preload when the + bpf filesystem is mounted. + bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards) bttv.radio= Most important insmod options are available as kernel args too. diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c index 619cdef0ba54..c1941c65ce95 100644 --- a/kernel/bpf/inode.c +++ b/kernel/bpf/inode.c @@ -22,7 +22,14 @@ #include <linux/bpf_trace.h> #include <linux/bpf_preload.h> -static char *bpf_preload_list_str; +static char *bpf_preload_list_str = CONFIG_BPF_PRELOAD_LIST; + +static int __init bpf_preload_list_setup(char *str) +{ + bpf_preload_list_str = str; + return 1; +} +__setup("bpf_preload_list=", bpf_preload_list_setup); static void *bpf_any_get(void *raw, enum bpf_type type) { @@ -732,7 +739,12 @@ static bool bpf_preload_list_mod_get(void) struct bpf_preload_ops_item *cur; bool ret = false; - ret |= bpf_preload_mod_get("bpf_preload", &bpf_preload_ops); + /* + * Keep the legacy registration method, but do not attempt to load + * bpf_preload.ko, as it switched to the new registration method. + */ + if (bpf_preload_ops) + ret |= bpf_preload_mod_get("bpf_preload", &bpf_preload_ops); list_for_each_entry(cur, &preload_list, list) ret |= bpf_preload_mod_get(cur->obj_name, &cur->ops); diff --git a/kernel/bpf/preload/Kconfig b/kernel/bpf/preload/Kconfig index c9d45c9d6918..f878e537b0ff 100644 --- a/kernel/bpf/preload/Kconfig +++ b/kernel/bpf/preload/Kconfig @@ -4,7 +4,7 @@ config USERMODE_DRIVER default n menuconfig BPF_PRELOAD - bool "Preload BPF file system with kernel specific program and map iterators" + bool "Preload eBPF programs" depends on BPF depends on BPF_SYSCALL # The dependency on !COMPILE_TEST prevents it from being enabled @@ -12,15 +12,26 @@ menuconfig BPF_PRELOAD depends on !COMPILE_TEST select USERMODE_DRIVER help - This builds kernel module with several embedded BPF programs that are - pinned into BPF FS mount point as human readable files that are - useful in debugging and introspection of BPF programs and maps. + This enables preloading eBPF programs chosen from the kernel + configuration or from the kernel option bpf_preload_list=. if BPF_PRELOAD config BPF_PRELOAD_UMD - tristate "bpf_preload kernel module" + tristate "Preload BPF file system with kernel specific program and map iterators" default m help - This builds bpf_preload kernel module with embedded BPF programs for - introspection in bpffs. + This builds bpf_preload kernel module with several embedded BPF + programs that are pinned into BPF FS mount point as human readable + files that are useful in debugging and introspection of BPF programs + and maps. + +config BPF_PRELOAD_LIST + string "Ordered list of eBPF programs to preload" + default "bpf_preload" + help + A comma-separated list of eBPF programs to preload. Any eBPF program + left off this list will be ignored. This can be controlled at boot + with the "bpf_preload_list=" parameter. + + If unsure, leave this as the default. endif diff --git a/kernel/bpf/preload/bpf_preload_kern.c b/kernel/bpf/preload/bpf_preload_kern.c index 3839af367200..c6d97872225b 100644 --- a/kernel/bpf/preload/bpf_preload_kern.c +++ b/kernel/bpf/preload/bpf_preload_kern.c @@ -5,22 +5,6 @@ #include <linux/bpf_preload.h> #include "iterators/iterators.lskel.h" -static int __init load(void) -{ - int err; - - err = load_skel(); - if (err) - return err; - bpf_preload_ops = &ops; - return err; -} - -static void __exit fini(void) -{ - bpf_preload_ops = NULL; - free_objs_and_skel(); -} -late_initcall(load); -module_exit(fini); +late_initcall(load_skel); +module_exit(free_objs_and_skel); MODULE_LICENSE("GPL"); diff --git a/kernel/bpf/preload/iterators/iterators.lskel.h b/kernel/bpf/preload/iterators/iterators.lskel.h index 7595fc283a65..5e999564cc7a 100644 --- a/kernel/bpf/preload/iterators/iterators.lskel.h +++ b/kernel/bpf/preload/iterators/iterators.lskel.h @@ -440,6 +440,8 @@ static struct iterators_bpf *skel; static void free_objs_and_skel(void) { + bpf_preload_set_ops("bpf_preload", THIS_MODULE, NULL); + if (!IS_ERR_OR_NULL(dump_bpf_map_link)) bpf_link_put(dump_bpf_map_link); if (!IS_ERR_OR_NULL(dump_bpf_prog_link)) @@ -481,11 +483,14 @@ static struct bpf_preload_ops ops = { static int load_skel(void) { - int err; + int err = -ENOMEM; + + if (!bpf_preload_set_ops("bpf_preload", THIS_MODULE, &ops)) + return 0; skel = iterators_bpf__open(); if (!skel) - return -ENOMEM; + goto out; err = iterators_bpf__load(skel); if (err) diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c index 5593cbee1846..af939183f57a 100644 --- a/tools/bpf/bpftool/gen.c +++ b/tools/bpf/bpftool/gen.c @@ -700,7 +700,10 @@ static void codegen_preload_free(struct bpf_object *obj, const char *obj_name) \n\ static void free_objs_and_skel(void) \n\ { \n\ - "); + bpf_preload_set_ops(\"%s\", THIS_MODULE, NULL); \n\ + \n\ + ", !strcmp(obj_name, "iterators_bpf") ? + "bpf_preload" : obj_name); bpf_object__for_each_program(prog, obj) { codegen("\ @@ -864,11 +867,14 @@ static void codegen_preload_load(struct bpf_object *obj, const char *obj_name) \n\ static int load_skel(void) \n\ { \n\ - int err; \n\ + int err = -ENOMEM; \n\ + \n\ + if (!bpf_preload_set_ops(\"%2$s\", THIS_MODULE, &ops)) \n\ + return 0; \n\ \n\ skel = %1$s__open(); \n\ if (!skel) \n\ - return -ENOMEM; \n\ + goto out; \n\ \n\ err = %1$s__load(skel); \n\ if (err) \n\ @@ -877,7 +883,8 @@ static void codegen_preload_load(struct bpf_object *obj, const char *obj_name) err = %1$s__attach(skel); \n\ if (err) \n\ goto out; \n\ - ", obj_name); + ", obj_name, !strcmp(obj_name, "iterators_bpf") ? + "bpf_preload" : obj_name); bpf_object__for_each_program(prog, obj) { codegen("\
Modify the automatic generator of the light skeleton by adding three calls to bpf_preload_set_ops() for registering and unregistering a preload method, two in load_skel() (set and unset if there is an error) and one in free_objs_and_skel(). Regenerate the light skeleton of the already preloaded eBPF program iterators_bpf, which will now use the new registration method, and directly call load_skel() and free_objs_and_skel() in the init and fini module entrypoints. Finally, allow users to specify a customized list of eBPF programs to preload with the CONFIG_BPF_PRELOAD_LIST option in the kernel configuration, at build time, or with new kernel option bpf_preload_list=, at run-time. By default, set CONFIG_BPF_PRELOAD_LIST to 'bpf_preload', so that the current preloading behavior is kept unchanged. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> --- .../admin-guide/kernel-parameters.txt | 8 ++++++ kernel/bpf/inode.c | 16 ++++++++++-- kernel/bpf/preload/Kconfig | 25 +++++++++++++------ kernel/bpf/preload/bpf_preload_kern.c | 20 ++------------- .../bpf/preload/iterators/iterators.lskel.h | 9 +++++-- tools/bpf/bpftool/gen.c | 15 ++++++++--- 6 files changed, 60 insertions(+), 33 deletions(-)