[PATCH bpf-next v2 0/2] bpf, btf: Add DEBUG_INFO_BTF checks for __register_bpf_struct

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* [PATCH bpf-next v2 0/2] bpf, btf: Add DEBUG_INFO_BTF checks for __register_bpf_struct_ops
@ 2024-02-03  7:51 Geliang Tang
  2024-02-03  7:51 ` [PATCH bpf-next v2 1/2] bpf, btf: Add register_check_missing_btf helper Geliang Tang
  2024-02-03  7:51 ` [PATCH bpf-next v2 2/2] bpf, btf: Check btf for register_bpf_struct_ops Geliang Tang
  0 siblings, 2 replies; 5+ messages in thread
From: Geliang Tang @ 2024-02-03  7:51 UTC (permalink / raw)
  To: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko,
	Martin KaFai Lau, Song Liu, Yonghong Song, Matthieu Baerts,
	Eduard Zingerman, John Fastabend, KP Singh, Stanislav Fomichev,
	Hao Luo, Jiri Olsa
  Cc: Geliang Tang, bpf, mptcp

From: Geliang Tang <tanggeliang@kylinos.cn>

v2:
 - add register_check_missing_btf helper as Jiri suggested.

Geliang Tang (2):
  bpf, btf: Add register_check_missing_btf helper
  bpf, btf: Check btf for register_bpf_struct_ops

 kernel/bpf/btf.c | 46 +++++++++++++++++++++++++---------------------
 1 file changed, 25 insertions(+), 21 deletions(-)

-- 
2.40.1


^ permalink raw reply	[flat|nested] 5+ messages in thread

* [PATCH bpf-next v2 1/2] bpf, btf: Add register_check_missing_btf helper
  2024-02-03  7:51 [PATCH bpf-next v2 0/2] bpf, btf: Add DEBUG_INFO_BTF checks for __register_bpf_struct_ops Geliang Tang
@ 2024-02-03  7:51 ` Geliang Tang
  2024-02-04  0:14   ` kernel test robot
  2024-02-04  1:19   ` kernel test robot
  2024-02-03  7:51 ` [PATCH bpf-next v2 2/2] bpf, btf: Check btf for register_bpf_struct_ops Geliang Tang
  1 sibling, 2 replies; 5+ messages in thread
From: Geliang Tang @ 2024-02-03  7:51 UTC (permalink / raw)
  To: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko,
	Martin KaFai Lau, Song Liu, Yonghong Song, Matthieu Baerts,
	Eduard Zingerman, John Fastabend, KP Singh, Stanislav Fomichev,
	Hao Luo, Jiri Olsa
  Cc: Geliang Tang, bpf, mptcp

From: Geliang Tang <tanggeliang@kylinos.cn>

This patch extracts duplicate code on error path when btf_get_module_btf()
returns NULL from the functions __register_btf_kfunc_id_set() and
register_btf_id_dtor_kfuncs() into a new helper named
register_check_missing_btf() to check CONFIG_DEBUG_INFO_BTF,
CONFIG_DEBUG_INFO_BTF_MODULES and CONFIG_MODULE_ALLOW_BTF_MISMATCH in it.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 kernel/bpf/btf.c | 42 ++++++++++++++++++++++--------------------
 1 file changed, 22 insertions(+), 20 deletions(-)

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index f7725cb6e564..1ebe26a3a7a5 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -7738,6 +7738,24 @@ static struct btf *btf_get_module_btf(const struct module *module)
 	return btf;
 }
 
+static int register_check_missing_btf(const struct module *module, const char *msg)
+{
+	if (!module && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) {
+		pr_err("missing vmlinux BTF, cannot register %s\n", msg);
+		return -ENOENT;
+	}
+	if (module && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES)) {
+		if (IS_ENABLED(CONFIG_MODULE_ALLOW_BTF_MISMATCH)) {
+			pr_warn("allow module %s BTF mismatch, skip register %s\n",
+				module->name, msg);
+			return 0;
+		}
+		pr_err("missing module %s BTF, cannot register %s\n", module->name, msg);
+		return -ENOENT;
+	}
+	return 0;
+}
+
 BPF_CALL_4(bpf_btf_find_by_name_kind, char *, name, int, name_sz, u32, kind, int, flags)
 {
 	struct btf *btf = NULL;
@@ -8098,15 +8116,8 @@ static int __register_btf_kfunc_id_set(enum btf_kfunc_hook hook,
 	int ret, i;
 
 	btf = btf_get_module_btf(kset->owner);
-	if (!btf) {
-		if (!kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) {
-			pr_err("missing vmlinux BTF, cannot register kfuncs\n");
-			return -ENOENT;
-		}
-		if (kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES))
-			pr_warn("missing module BTF, cannot register kfuncs\n");
-		return 0;
-	}
+	if (!btf)
+		return register_check_missing_btf(kset->owner, "kfuncs");
 	if (IS_ERR(btf))
 		return PTR_ERR(btf);
 
@@ -8214,17 +8225,8 @@ int register_btf_id_dtor_kfuncs(const struct btf_id_dtor_kfunc *dtors, u32 add_c
 	int ret;
 
 	btf = btf_get_module_btf(owner);
-	if (!btf) {
-		if (!owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) {
-			pr_err("missing vmlinux BTF, cannot register dtor kfuncs\n");
-			return -ENOENT;
-		}
-		if (owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES)) {
-			pr_err("missing module BTF, cannot register dtor kfuncs\n");
-			return -ENOENT;
-		}
-		return 0;
-	}
+	if (!btf)
+		return register_check_missing_btf(owner, "dtor kfuncs");
 	if (IS_ERR(btf))
 		return PTR_ERR(btf);
 
-- 
2.40.1


^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [PATCH bpf-next v2 1/2] bpf, btf: Add register_check_missing_btf helper
  2024-02-03  7:51 ` [PATCH bpf-next v2 1/2] bpf, btf: Add register_check_missing_btf helper Geliang Tang
@ 2024-02-04  0:14   ` kernel test robot
  2024-02-04  1:19   ` kernel test robot
  1 sibling, 0 replies; 5+ messages in thread
From: kernel test robot @ 2024-02-04  0:14 UTC (permalink / raw)
  To: Geliang Tang, Alexei Starovoitov, Daniel Borkmann,
	Andrii Nakryiko, Martin KaFai Lau, Song Liu, Yonghong Song,
	Matthieu Baerts, Eduard Zingerman, John Fastabend, KP Singh,
	Stanislav Fomichev, Hao Luo, Jiri Olsa
  Cc: oe-kbuild-all, Geliang Tang, bpf, mptcp

Hi Geliang,

kernel test robot noticed the following build errors:

[auto build test ERROR on bpf-next/master]

url:    https://github.com/intel-lab-lkp/linux/commits/Geliang-Tang/bpf-btf-Add-register_check_missing_btf-helper/20240203-155524
base:   https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
patch link:    https://lore.kernel.org/r/f4b147ddaa8fe8c07c7ba77a1d61780bffc49bb6.1706946547.git.tanggeliang%40kylinos.cn
patch subject: [PATCH bpf-next v2 1/2] bpf, btf: Add register_check_missing_btf helper
config: arm-randconfig-001-20240204 (https://download.01.org/0day-ci/archive/20240204/202402040740.WcfFYJQX-lkp@intel.com/config)
compiler: arm-linux-gnueabi-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240204/202402040740.WcfFYJQX-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202402040740.WcfFYJQX-lkp@intel.com/

All errors (new ones prefixed by >>):

   kernel/bpf/btf.c: In function 'btf_seq_show':
   kernel/bpf/btf.c:7286:29: warning: function 'btf_seq_show' might be a candidate for 'gnu_printf' format attribute [-Wsuggest-attribute=format]
    7286 |         seq_vprintf((struct seq_file *)show->target, fmt, args);
         |                             ^~~~~~~~
   kernel/bpf/btf.c: In function 'btf_snprintf_show':
   kernel/bpf/btf.c:7323:9: warning: function 'btf_snprintf_show' might be a candidate for 'gnu_printf' format attribute [-Wsuggest-attribute=format]
    7323 |         len = vsnprintf(show->target, ssnprintf->len_left, fmt, args);
         |         ^~~
   In file included from include/asm-generic/bug.h:22,
                    from arch/arm/include/asm/bug.h:60,
                    from include/linux/bug.h:5,
                    from include/linux/thread_info.h:13,
                    from include/linux/sched.h:14,
                    from include/linux/ptrace.h:6,
                    from include/uapi/asm-generic/bpf_perf_event.h:4,
                    from ./arch/arm/include/generated/uapi/asm/bpf_perf_event.h:1,
                    from include/uapi/linux/bpf_perf_event.h:11,
                    from kernel/bpf/btf.c:6:
   kernel/bpf/btf.c: In function 'register_check_missing_btf':
>> kernel/bpf/btf.c:7750:39: error: invalid use of undefined type 'const struct module'
    7750 |                                 module->name, msg);
         |                                       ^~
   include/linux/printk.h:427:33: note: in definition of macro 'printk_index_wrap'
     427 |                 _p_func(_fmt, ##__VA_ARGS__);                           \
         |                                 ^~~~~~~~~~~
   include/linux/printk.h:508:9: note: in expansion of macro 'printk'
     508 |         printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
         |         ^~~~~~
   kernel/bpf/btf.c:7749:25: note: in expansion of macro 'pr_warn'
    7749 |                         pr_warn("allow module %s BTF mismatch, skip register %s\n",
         |                         ^~~~~~~
   kernel/bpf/btf.c:7753:77: error: invalid use of undefined type 'const struct module'
    7753 |                 pr_err("missing module %s BTF, cannot register %s\n", module->name, msg);
         |                                                                             ^~
   include/linux/printk.h:427:33: note: in definition of macro 'printk_index_wrap'
     427 |                 _p_func(_fmt, ##__VA_ARGS__);                           \
         |                                 ^~~~~~~~~~~
   include/linux/printk.h:498:9: note: in expansion of macro 'printk'
     498 |         printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
         |         ^~~~~~
   kernel/bpf/btf.c:7753:17: note: in expansion of macro 'pr_err'
    7753 |                 pr_err("missing module %s BTF, cannot register %s\n", module->name, msg);
         |                 ^~~~~~


vim +7750 kernel/bpf/btf.c

  7740	
  7741	static int register_check_missing_btf(const struct module *module, const char *msg)
  7742	{
  7743		if (!module && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) {
  7744			pr_err("missing vmlinux BTF, cannot register %s\n", msg);
  7745			return -ENOENT;
  7746		}
  7747		if (module && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES)) {
  7748			if (IS_ENABLED(CONFIG_MODULE_ALLOW_BTF_MISMATCH)) {
  7749				pr_warn("allow module %s BTF mismatch, skip register %s\n",
> 7750					module->name, msg);
  7751				return 0;
  7752			}
  7753			pr_err("missing module %s BTF, cannot register %s\n", module->name, msg);
  7754			return -ENOENT;
  7755		}
  7756		return 0;
  7757	}
  7758	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH bpf-next v2 1/2] bpf, btf: Add register_check_missing_btf helper
  2024-02-03  7:51 ` [PATCH bpf-next v2 1/2] bpf, btf: Add register_check_missing_btf helper Geliang Tang
  2024-02-04  0:14   ` kernel test robot
@ 2024-02-04  1:19   ` kernel test robot
  1 sibling, 0 replies; 5+ messages in thread
From: kernel test robot @ 2024-02-04  1:19 UTC (permalink / raw)
  To: Geliang Tang, Alexei Starovoitov, Daniel Borkmann,
	Andrii Nakryiko, Martin KaFai Lau, Song Liu, Yonghong Song,
	Matthieu Baerts, Eduard Zingerman, John Fastabend, KP Singh,
	Stanislav Fomichev, Hao Luo, Jiri Olsa
  Cc: llvm, oe-kbuild-all, Geliang Tang, bpf, mptcp

Hi Geliang,

kernel test robot noticed the following build errors:

[auto build test ERROR on bpf-next/master]

url:    https://github.com/intel-lab-lkp/linux/commits/Geliang-Tang/bpf-btf-Add-register_check_missing_btf-helper/20240203-155524
base:   https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
patch link:    https://lore.kernel.org/r/f4b147ddaa8fe8c07c7ba77a1d61780bffc49bb6.1706946547.git.tanggeliang%40kylinos.cn
patch subject: [PATCH bpf-next v2 1/2] bpf, btf: Add register_check_missing_btf helper
config: arm-imxrt_defconfig (https://download.01.org/0day-ci/archive/20240204/202402040934.Fph0XeEo-lkp@intel.com/config)
compiler: clang version 19.0.0git (https://github.com/llvm/llvm-project 7dd790db8b77c4a833c06632e903dc4f13877a64)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240204/202402040934.Fph0XeEo-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202402040934.Fph0XeEo-lkp@intel.com/

All errors (new ones prefixed by >>):

>> kernel/bpf/btf.c:7750:11: error: incomplete definition of type 'struct module'
    7750 |                                 module->name, msg);
         |                                 ~~~~~~^
   include/linux/printk.h:508:37: note: expanded from macro 'pr_warn'
     508 |         printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
         |                                            ^~~~~~~~~~~
   include/linux/printk.h:455:60: note: expanded from macro 'printk'
     455 | #define printk(fmt, ...) printk_index_wrap(_printk, fmt, ##__VA_ARGS__)
         |                                                            ^~~~~~~~~~~
   include/linux/printk.h:427:19: note: expanded from macro 'printk_index_wrap'
     427 |                 _p_func(_fmt, ##__VA_ARGS__);                           \
         |                                 ^~~~~~~~~~~
   include/linux/printk.h:348:8: note: forward declaration of 'struct module'
     348 | struct module;
         |        ^
   kernel/bpf/btf.c:7753:63: error: incomplete definition of type 'struct module'
    7753 |                 pr_err("missing module %s BTF, cannot register %s\n", module->name, msg);
         |                                                                       ~~~~~~^
   include/linux/printk.h:498:33: note: expanded from macro 'pr_err'
     498 |         printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
         |                                        ^~~~~~~~~~~
   include/linux/printk.h:455:60: note: expanded from macro 'printk'
     455 | #define printk(fmt, ...) printk_index_wrap(_printk, fmt, ##__VA_ARGS__)
         |                                                            ^~~~~~~~~~~
   include/linux/printk.h:427:19: note: expanded from macro 'printk_index_wrap'
     427 |                 _p_func(_fmt, ##__VA_ARGS__);                           \
         |                                 ^~~~~~~~~~~
   include/linux/printk.h:348:8: note: forward declaration of 'struct module'
     348 | struct module;
         |        ^
   2 errors generated.


vim +7750 kernel/bpf/btf.c

  7740	
  7741	static int register_check_missing_btf(const struct module *module, const char *msg)
  7742	{
  7743		if (!module && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) {
  7744			pr_err("missing vmlinux BTF, cannot register %s\n", msg);
  7745			return -ENOENT;
  7746		}
  7747		if (module && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES)) {
  7748			if (IS_ENABLED(CONFIG_MODULE_ALLOW_BTF_MISMATCH)) {
  7749				pr_warn("allow module %s BTF mismatch, skip register %s\n",
> 7750					module->name, msg);
  7751				return 0;
  7752			}
  7753			pr_err("missing module %s BTF, cannot register %s\n", module->name, msg);
  7754			return -ENOENT;
  7755		}
  7756		return 0;
  7757	}
  7758	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

^ permalink raw reply	[flat|nested] 5+ messages in thread

* [PATCH bpf-next v2 2/2] bpf, btf: Check btf for register_bpf_struct_ops
  2024-02-03  7:51 [PATCH bpf-next v2 0/2] bpf, btf: Add DEBUG_INFO_BTF checks for __register_bpf_struct_ops Geliang Tang
  2024-02-03  7:51 ` [PATCH bpf-next v2 1/2] bpf, btf: Add register_check_missing_btf helper Geliang Tang
@ 2024-02-03  7:51 ` Geliang Tang
  1 sibling, 0 replies; 5+ messages in thread
From: Geliang Tang @ 2024-02-03  7:51 UTC (permalink / raw)
  To: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko,
	Martin KaFai Lau, Song Liu, Yonghong Song, Matthieu Baerts,
	Eduard Zingerman, John Fastabend, KP Singh, Stanislav Fomichev,
	Hao Luo, Jiri Olsa
  Cc: Geliang Tang, bpf, mptcp

From: Geliang Tang <tanggeliang@kylinos.cn>

Similar to the handling in the functions __register_btf_kfunc_id_set()
and register_btf_id_dtor_kfuncs(), this patch uses the newly added
helper register_check_missing_btf() and IS_ERR() to check the return
value of btf_get_module_btf().

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 kernel/bpf/btf.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 1ebe26a3a7a5..2d99f85adc82 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -8889,7 +8889,9 @@ int __register_bpf_struct_ops(struct bpf_struct_ops *st_ops)
 
 	btf = btf_get_module_btf(st_ops->owner);
 	if (!btf)
-		return -EINVAL;
+		return register_check_missing_btf(st_ops->owner, "structs");
+	if (IS_ERR(btf))
+		return PTR_ERR(btf);
 
 	log = kzalloc(sizeof(*log), GFP_KERNEL | __GFP_NOWARN);
 	if (!log) {
-- 
2.40.1


^ permalink raw reply related	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2024-02-04  1:19 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2024-02-03  7:51 [PATCH bpf-next v2 0/2] bpf, btf: Add DEBUG_INFO_BTF checks for __register_bpf_struct_ops Geliang Tang
2024-02-03  7:51 ` [PATCH bpf-next v2 1/2] bpf, btf: Add register_check_missing_btf helper Geliang Tang
2024-02-04  0:14   ` kernel test robot
2024-02-04  1:19   ` kernel test robot
2024-02-03  7:51 ` [PATCH bpf-next v2 2/2] bpf, btf: Check btf for register_bpf_struct_ops Geliang Tang

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