From f28771c0691bcb7f477a0f35550b17b88c32dea8 Mon Sep 17 00:00:00 2001 From: Leon Hwang Date: Tue, 12 May 2026 23:31:50 +0800 Subject: bpf: Extend BPF syscall with common attributes support Add generic BPF syscall support for passing common attributes. The initial set of common attributes includes: 1. 'log_buf': User-provided buffer for storing logs. 2. 'log_size': Size of the log buffer. 3. 'log_level': Log verbosity level. 4. 'log_true_size': Actual log size reported by kernel. The common-attribute pointer and its size are passed as the 4th and 5th syscall arguments. A new command bit, 'BPF_COMMON_ATTRS' ('1 << 16'), indicates that common attributes are supplied. This commit adds syscall and uapi plumbing. Command-specific handling is added in follow-up patches. Signed-off-by: Leon Hwang Link: https://lore.kernel.org/r/20260512153157.28382-2-leon.hwang@linux.dev Signed-off-by: Alexei Starovoitov --- include/linux/syscalls.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index f5639d5ac331..50055ab73649 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -936,7 +936,8 @@ asmlinkage long sys_seccomp(unsigned int op, unsigned int flags, asmlinkage long sys_getrandom(char __user *buf, size_t count, unsigned int flags); asmlinkage long sys_memfd_create(const char __user *uname_ptr, unsigned int flags); -asmlinkage long sys_bpf(int cmd, union bpf_attr __user *attr, unsigned int size); +asmlinkage long sys_bpf(int cmd, union bpf_attr __user *attr, unsigned int size, + struct bpf_common_attr __user *attr_common, unsigned int size_common); asmlinkage long sys_execveat(int dfd, const char __user *filename, const char __user *const __user *argv, const char __user *const __user *envp, int flags); -- cgit v1.2.3 From 503c039ffeca7530ce9d6446a07b4bb776180b45 Mon Sep 17 00:00:00 2001 From: Leon Hwang Date: Tue, 12 May 2026 23:31:52 +0800 Subject: bpf: Refactor reporting log_true_size for prog_load The next commit will add support for reporting logs via extended common attributes, including 'log_true_size'. To prepare for that, refactor the 'log_true_size' reporting logic by introducing a new struct bpf_log_attr to encapsulate log-related behavior: * bpf_log_attr_init(): initialize log fields, which will support extended common attributes in the next commit. * bpf_log_attr_finalize(): handle log finalization and write back 'log_true_size' to userspace. Acked-by: Andrii Nakryiko Signed-off-by: Leon Hwang Link: https://lore.kernel.org/r/20260512153157.28382-4-leon.hwang@linux.dev Signed-off-by: Alexei Starovoitov --- include/linux/bpf.h | 4 +++- include/linux/bpf_verifier.h | 12 ++++++++++++ kernel/bpf/log.c | 29 +++++++++++++++++++++++++++++ kernel/bpf/syscall.c | 12 +++++++++--- kernel/bpf/verifier.c | 17 ++++------------- 5 files changed, 57 insertions(+), 17 deletions(-) (limited to 'include/linux') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 14759972f148..9e16e91647d3 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2919,7 +2919,9 @@ int bpf_check_uarg_tail_zero(bpfptr_t uaddr, size_t expected_size, size_t actual_size); /* verify correctness of eBPF program */ -int bpf_check(struct bpf_prog **fp, union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size); +struct bpf_log_attr; +int bpf_check(struct bpf_prog **fp, union bpf_attr *attr, bpfptr_t uattr, + struct bpf_log_attr *attr_log); #ifndef CONFIG_BPF_JIT_ALWAYS_ON void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth); diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index 976e2b2f40e8..8d27ad1f9f94 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -755,6 +755,18 @@ static inline bool bpf_verifier_log_needed(const struct bpf_verifier_log *log) return log && log->level; } +struct bpf_log_attr { + char __user *ubuf; + u32 size; + u32 level; + u32 offsetof_true_size; + bpfptr_t uattr; +}; + +int bpf_log_attr_init(struct bpf_log_attr *log, u64 log_buf, u32 log_size, u32 log_level, + u32 offsetof_log_true_size, bpfptr_t uattr); +int bpf_log_attr_finalize(struct bpf_log_attr *attr, struct bpf_verifier_log *log); + #define BPF_MAX_SUBPROGS 256 struct bpf_subprog_arg_info { diff --git a/kernel/bpf/log.c b/kernel/bpf/log.c index 64566b86dd27..1b1efe75398b 100644 --- a/kernel/bpf/log.c +++ b/kernel/bpf/log.c @@ -825,3 +825,32 @@ void print_insn_state(struct bpf_verifier_env *env, const struct bpf_verifier_st } print_verifier_state(env, vstate, frameno, false); } + +int bpf_log_attr_init(struct bpf_log_attr *log, u64 log_buf, u32 log_size, u32 log_level, + u32 offsetof_log_true_size, bpfptr_t uattr) +{ + char __user *ubuf = u64_to_user_ptr(log_buf); + + memset(log, 0, sizeof(*log)); + log->ubuf = ubuf; + log->size = log_size; + log->level = log_level; + log->offsetof_true_size = offsetof_log_true_size; + log->uattr = uattr; + return 0; +} + +int bpf_log_attr_finalize(struct bpf_log_attr *attr, struct bpf_verifier_log *log) +{ + u32 log_true_size; + int err; + + err = bpf_vlog_finalize(log, &log_true_size); + + if (attr->offsetof_true_size && + copy_to_bpfptr_offset(attr->uattr, attr->offsetof_true_size, &log_true_size, + sizeof(log_true_size))) + return -EFAULT; + + return err; +} diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 354f6f471a08..70b78ddcdedb 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2861,7 +2861,7 @@ static int bpf_prog_mark_insn_arrays_ready(struct bpf_prog *prog) /* last field in 'union bpf_attr' used by this command */ #define BPF_PROG_LOAD_LAST_FIELD keyring_id -static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size) +static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, struct bpf_log_attr *attr_log) { enum bpf_prog_type type = attr->prog_type; struct bpf_prog *prog, *dst_prog = NULL; @@ -3079,7 +3079,7 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size) goto free_prog_sec; /* run eBPF verifier */ - err = bpf_check(&prog, attr, uattr, uattr_size); + err = bpf_check(&prog, attr, uattr, attr_log); if (err < 0) goto free_used_maps; @@ -6215,6 +6215,8 @@ static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size, bpfptr_t uattr_common, unsigned int size_common) { struct bpf_common_attr attr_common; + u32 offsetof_log_true_size = 0; + struct bpf_log_attr attr_log; union bpf_attr attr; int err; @@ -6266,7 +6268,11 @@ static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size, err = map_freeze(&attr); break; case BPF_PROG_LOAD: - err = bpf_prog_load(&attr, uattr, size); + if (size >= offsetofend(union bpf_attr, log_true_size)) + offsetof_log_true_size = offsetof(union bpf_attr, log_true_size); + err = bpf_log_attr_init(&attr_log, attr.log_buf, attr.log_size, attr.log_level, + offsetof_log_true_size, uattr); + err = err ?: bpf_prog_load(&attr, uattr, &attr_log); break; case BPF_OBJ_PIN: err = bpf_obj_pin(&attr); diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 11054ad89c14..0e654ef01ae0 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -19294,12 +19294,12 @@ int bpf_fixup_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, return 0; } -int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size) +int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, + struct bpf_log_attr *attr_log) { u64 start_time = ktime_get_ns(); struct bpf_verifier_env *env; int i, len, ret = -EINVAL, err; - u32 log_true_size; bool is_priv; BTF_TYPE_EMIT(enum bpf_features); @@ -19346,9 +19346,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u3 /* user could have requested verbose verifier output * and supplied buffer to store the verification trace */ - ret = bpf_vlog_init(&env->log, attr->log_level, - (char __user *) (unsigned long) attr->log_buf, - attr->log_size); + ret = bpf_vlog_init(&env->log, attr_log->level, attr_log->ubuf, attr_log->size); if (ret) goto err_unlock; @@ -19510,17 +19508,10 @@ skip_full_check: env->prog->aux->verified_insns = env->insn_processed; /* preserve original error even if log finalization is successful */ - err = bpf_vlog_finalize(&env->log, &log_true_size); + err = bpf_log_attr_finalize(attr_log, &env->log); if (err) ret = err; - if (uattr_size >= offsetofend(union bpf_attr, log_true_size) && - copy_to_bpfptr_offset(uattr, offsetof(union bpf_attr, log_true_size), - &log_true_size, sizeof(log_true_size))) { - ret = -EFAULT; - goto err_release_maps; - } - if (ret) goto err_release_maps; -- cgit v1.2.3 From ac89d33fdd8183df39fe92ffa525be7af6feb9d1 Mon Sep 17 00:00:00 2001 From: Leon Hwang Date: Tue, 12 May 2026 23:31:53 +0800 Subject: bpf: Add syscall common attributes support for prog_load BPF_PROG_LOAD can now take log parameters from both union bpf_attr and struct bpf_common_attr. The merge rules are: - if both sides provide a complete log tuple (buf/size/level) and they match, use it; - if only one side provides log parameters, use that one; - if both sides provide complete tuples but they differ, return -EINVAL. Signed-off-by: Leon Hwang Link: https://lore.kernel.org/r/20260512153157.28382-5-leon.hwang@linux.dev Signed-off-by: Alexei Starovoitov --- include/linux/bpf_verifier.h | 3 ++- kernel/bpf/log.c | 34 +++++++++++++++++++++++++++------- kernel/bpf/syscall.c | 3 ++- 3 files changed, 31 insertions(+), 9 deletions(-) (limited to 'include/linux') diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index 8d27ad1f9f94..8433430dedb7 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -764,7 +764,8 @@ struct bpf_log_attr { }; int bpf_log_attr_init(struct bpf_log_attr *log, u64 log_buf, u32 log_size, u32 log_level, - u32 offsetof_log_true_size, bpfptr_t uattr); + u32 offsetof_log_true_size, bpfptr_t uattr, struct bpf_common_attr *common, + bpfptr_t uattr_common, u32 size_common); int bpf_log_attr_finalize(struct bpf_log_attr *attr, struct bpf_verifier_log *log); #define BPF_MAX_SUBPROGS 256 diff --git a/kernel/bpf/log.c b/kernel/bpf/log.c index 1b1efe75398b..fd12ad5a0338 100644 --- a/kernel/bpf/log.c +++ b/kernel/bpf/log.c @@ -13,17 +13,17 @@ #define verbose(env, fmt, args...) bpf_verifier_log_write(env, fmt, ##args) -static bool bpf_verifier_log_attr_valid(const struct bpf_verifier_log *log) +static bool bpf_verifier_log_attr_valid(u32 log_level, char __user *log_buf, u32 log_size) { /* ubuf and len_total should both be specified (or not) together */ - if (!!log->ubuf != !!log->len_total) + if (!!log_buf != !!log_size) return false; /* log buf without log_level is meaningless */ - if (log->ubuf && log->level == 0) + if (log_buf && log_level == 0) return false; - if (log->level & ~BPF_LOG_MASK) + if (log_level & ~BPF_LOG_MASK) return false; - if (log->len_total > UINT_MAX >> 2) + if (log_size > UINT_MAX >> 2) return false; return true; } @@ -36,7 +36,7 @@ int bpf_vlog_init(struct bpf_verifier_log *log, u32 log_level, log->len_total = log_size; /* log attributes have to be sane */ - if (!bpf_verifier_log_attr_valid(log)) + if (!bpf_verifier_log_attr_valid(log_level, log_buf, log_size)) return -EINVAL; return 0; @@ -827,16 +827,36 @@ void print_insn_state(struct bpf_verifier_env *env, const struct bpf_verifier_st } int bpf_log_attr_init(struct bpf_log_attr *log, u64 log_buf, u32 log_size, u32 log_level, - u32 offsetof_log_true_size, bpfptr_t uattr) + u32 offsetof_log_true_size, bpfptr_t uattr, struct bpf_common_attr *common, + bpfptr_t uattr_common, u32 size_common) { + char __user *ubuf_common = u64_to_user_ptr(common->log_buf); char __user *ubuf = u64_to_user_ptr(log_buf); + if (!bpf_verifier_log_attr_valid(common->log_level, ubuf_common, common->log_size) || + !bpf_verifier_log_attr_valid(log_level, ubuf, log_size)) + return -EINVAL; + + if (ubuf && ubuf_common && (ubuf != ubuf_common || log_size != common->log_size || + log_level != common->log_level)) + return -EINVAL; + memset(log, 0, sizeof(*log)); log->ubuf = ubuf; log->size = log_size; log->level = log_level; log->offsetof_true_size = offsetof_log_true_size; log->uattr = uattr; + + if (!ubuf && ubuf_common) { + log->ubuf = ubuf_common; + log->size = common->log_size; + log->level = common->log_level; + log->uattr = uattr_common; + log->offsetof_true_size = 0; + if (size_common >= offsetofend(struct bpf_common_attr, log_true_size)) + log->offsetof_true_size = offsetof(struct bpf_common_attr, log_true_size); + } return 0; } diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 70b78ddcdedb..db893cae826c 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -6271,7 +6271,8 @@ static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size, if (size >= offsetofend(union bpf_attr, log_true_size)) offsetof_log_true_size = offsetof(union bpf_attr, log_true_size); err = bpf_log_attr_init(&attr_log, attr.log_buf, attr.log_size, attr.log_level, - offsetof_log_true_size, uattr); + offsetof_log_true_size, uattr, &attr_common, uattr_common, + size_common); err = err ?: bpf_prog_load(&attr, uattr, &attr_log); break; case BPF_OBJ_PIN: -- cgit v1.2.3 From ceeb7eda94a3548958b30818495ef7eb12898727 Mon Sep 17 00:00:00 2001 From: Leon Hwang Date: Tue, 12 May 2026 23:31:54 +0800 Subject: bpf: Add syscall common attributes support for btf_load BPF_BTF_LOAD can now take log parameters from both union bpf_attr and struct bpf_common_attr, with the same merge rules as BPF_PROG_LOAD: - if both sides provide a complete log tuple (buf/size/level) and they match, use it; - if only one side provides log parameters, use that one; - if both sides provide complete tuples but they differ, return -EINVAL. Acked-by: Andrii Nakryiko Signed-off-by: Leon Hwang Link: https://lore.kernel.org/r/20260512153157.28382-6-leon.hwang@linux.dev Signed-off-by: Alexei Starovoitov --- include/linux/btf.h | 3 ++- kernel/bpf/btf.c | 30 +++++++----------------------- kernel/bpf/syscall.c | 11 ++++++++--- 3 files changed, 17 insertions(+), 27 deletions(-) (limited to 'include/linux') diff --git a/include/linux/btf.h b/include/linux/btf.h index c82d0d689059..240401d9b25b 100644 --- a/include/linux/btf.h +++ b/include/linux/btf.h @@ -145,7 +145,8 @@ const char *btf_get_name(const struct btf *btf); void btf_get(struct btf *btf); void btf_put(struct btf *btf); const struct btf_header *btf_header(const struct btf *btf); -int btf_new_fd(const union bpf_attr *attr, bpfptr_t uattr, u32 uattr_sz); +struct bpf_log_attr; +int btf_new_fd(const union bpf_attr *attr, bpfptr_t uattr, struct bpf_log_attr *attr_log); struct btf *btf_get_by_fd(int fd); int btf_get_info_by_fd(const struct btf *btf, const union bpf_attr *attr, diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 77af44d8a3ad..a6bf4781943c 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -5907,25 +5907,10 @@ static int btf_check_type_tags(struct btf_verifier_env *env, return 0; } -static int finalize_log(struct bpf_verifier_log *log, bpfptr_t uattr, u32 uattr_size) -{ - u32 log_true_size; - int err; - - err = bpf_vlog_finalize(log, &log_true_size); - - if (uattr_size >= offsetofend(union bpf_attr, btf_log_true_size) && - copy_to_bpfptr_offset(uattr, offsetof(union bpf_attr, btf_log_true_size), - &log_true_size, sizeof(log_true_size))) - err = -EFAULT; - - return err; -} - -static struct btf *btf_parse(const union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size) +static struct btf *btf_parse(const union bpf_attr *attr, bpfptr_t uattr, + struct bpf_log_attr *attr_log) { bpfptr_t btf_data = make_bpfptr(attr->btf, uattr.is_kernel); - char __user *log_ubuf = u64_to_user_ptr(attr->btf_log_buf); struct btf_struct_metas *struct_meta_tab; struct btf_verifier_env *env = NULL; struct btf *btf = NULL; @@ -5942,8 +5927,7 @@ static struct btf *btf_parse(const union bpf_attr *attr, bpfptr_t uattr, u32 uat /* user could have requested verbose verifier output * and supplied buffer to store the verification trace */ - err = bpf_vlog_init(&env->log, attr->btf_log_level, - log_ubuf, attr->btf_log_size); + err = bpf_vlog_init(&env->log, attr_log->level, attr_log->ubuf, attr_log->size); if (err) goto errout_free; @@ -6008,7 +5992,7 @@ static struct btf *btf_parse(const union bpf_attr *attr, bpfptr_t uattr, u32 uat } } - err = finalize_log(&env->log, uattr, uattr_size); + err = bpf_log_attr_finalize(attr_log, &env->log); if (err) goto errout_free; @@ -6020,7 +6004,7 @@ errout_meta: btf_free_struct_meta_tab(btf); errout: /* overwrite err with -ENOSPC or -EFAULT */ - ret = finalize_log(&env->log, uattr, uattr_size); + ret = bpf_log_attr_finalize(attr_log, &env->log); if (ret) err = ret; errout_free: @@ -8189,12 +8173,12 @@ static int __btf_new_fd(struct btf *btf) return anon_inode_getfd("btf", &btf_fops, btf, O_RDONLY | O_CLOEXEC); } -int btf_new_fd(const union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size) +int btf_new_fd(const union bpf_attr *attr, bpfptr_t uattr, struct bpf_log_attr *attr_log) { struct btf *btf; int ret; - btf = btf_parse(attr, uattr, uattr_size); + btf = btf_parse(attr, uattr, attr_log); if (IS_ERR(btf)) return PTR_ERR(btf); diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index db893cae826c..2fa05ba8f161 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -5474,7 +5474,7 @@ static int bpf_obj_get_info_by_fd(const union bpf_attr *attr, #define BPF_BTF_LOAD_LAST_FIELD btf_token_fd -static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size) +static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, struct bpf_log_attr *attr_log) { struct bpf_token *token = NULL; @@ -5501,7 +5501,7 @@ static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_ bpf_token_put(token); - return btf_new_fd(attr, uattr, uattr_size); + return btf_new_fd(attr, uattr, attr_log); } #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD fd_by_id_token_fd @@ -6318,7 +6318,12 @@ static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size, err = bpf_raw_tracepoint_open(&attr); break; case BPF_BTF_LOAD: - err = bpf_btf_load(&attr, uattr, size); + if (size >= offsetofend(union bpf_attr, btf_log_true_size)) + offsetof_log_true_size = offsetof(union bpf_attr, btf_log_true_size); + err = bpf_log_attr_init(&attr_log, attr.btf_log_buf, attr.btf_log_size, + attr.btf_log_level, offsetof_log_true_size, uattr, + &attr_common, uattr_common, size_common); + err = err ?: bpf_btf_load(&attr, uattr, &attr_log); break; case BPF_BTF_GET_FD_BY_ID: err = bpf_btf_get_fd_by_id(&attr); -- cgit v1.2.3 From 49f9b2b2a18c5ce06b21fc2b3399352d80dee0c6 Mon Sep 17 00:00:00 2001 From: Leon Hwang Date: Tue, 12 May 2026 23:31:55 +0800 Subject: bpf: Add syscall common attributes support for map_create Many BPF_MAP_CREATE validation failures currently return -EINVAL without any explanation to userspace. Plumb common syscall log attributes into map_create(), create a verifier log from bpf_common_attr::log_buf/log_size/log_level, and report map-creation failure reasons through that buffer. This improves debuggability by allowing userspace to inspect why map creation failed and read back log_true_size from common attributes. Signed-off-by: Leon Hwang Link: https://lore.kernel.org/r/20260512153157.28382-7-leon.hwang@linux.dev Signed-off-by: Alexei Starovoitov --- include/linux/bpf_verifier.h | 3 ++ kernel/bpf/log.c | 29 +++++++++++++++++++ kernel/bpf/syscall.c | 66 +++++++++++++++++++++++++++++++++++++------- 3 files changed, 88 insertions(+), 10 deletions(-) (limited to 'include/linux') diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index 8433430dedb7..c15a4c26a43b 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -766,6 +766,9 @@ struct bpf_log_attr { int bpf_log_attr_init(struct bpf_log_attr *log, u64 log_buf, u32 log_size, u32 log_level, u32 offsetof_log_true_size, bpfptr_t uattr, struct bpf_common_attr *common, bpfptr_t uattr_common, u32 size_common); +struct bpf_verifier_log *bpf_log_attr_create_vlog(struct bpf_log_attr *attr_log, + struct bpf_common_attr *common, bpfptr_t uattr, + u32 size); int bpf_log_attr_finalize(struct bpf_log_attr *attr, struct bpf_verifier_log *log); #define BPF_MAX_SUBPROGS 256 diff --git a/kernel/bpf/log.c b/kernel/bpf/log.c index fd12ad5a0338..62fe6ed18374 100644 --- a/kernel/bpf/log.c +++ b/kernel/bpf/log.c @@ -860,6 +860,35 @@ int bpf_log_attr_init(struct bpf_log_attr *log, u64 log_buf, u32 log_size, u32 l return 0; } +struct bpf_verifier_log *bpf_log_attr_create_vlog(struct bpf_log_attr *attr_log, + struct bpf_common_attr *common, bpfptr_t uattr, + u32 size) +{ + struct bpf_verifier_log *log; + int err; + + memset(attr_log, 0, sizeof(*attr_log)); + attr_log->uattr = uattr; + if (size >= offsetofend(struct bpf_common_attr, log_true_size)) + attr_log->offsetof_true_size = offsetof(struct bpf_common_attr, log_true_size); + + if (!size) + return NULL; + + log = kzalloc_obj(*log, GFP_KERNEL); + if (!log) + return ERR_PTR(-ENOMEM); + + err = bpf_vlog_init(log, common->log_level, u64_to_user_ptr(common->log_buf), + common->log_size); + if (err) { + kfree(log); + return ERR_PTR(err); + } + + return log; +} + int bpf_log_attr_finalize(struct bpf_log_attr *attr, struct bpf_verifier_log *log) { u32 log_true_size; diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 2fa05ba8f161..6600e126fbfb 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1359,7 +1359,7 @@ free_map_tab: #define BPF_MAP_CREATE_LAST_FIELD excl_prog_hash_size /* called via syscall */ -static int map_create(union bpf_attr *attr, bpfptr_t uattr) +static int __map_create(union bpf_attr *attr, bpfptr_t uattr, struct bpf_verifier_log *log) { const struct bpf_map_ops *ops; struct bpf_token *token = NULL; @@ -1371,8 +1371,10 @@ static int map_create(union bpf_attr *attr, bpfptr_t uattr) int err; err = CHECK_ATTR(BPF_MAP_CREATE); - if (err) + if (err) { + bpf_log(log, "Invalid attr.\n"); return -EINVAL; + } /* check BPF_F_TOKEN_FD flag, remember if it's set, and then clear it * to avoid per-map type checks tripping on unknown flag @@ -1381,17 +1383,25 @@ static int map_create(union bpf_attr *attr, bpfptr_t uattr) attr->map_flags &= ~BPF_F_TOKEN_FD; if (attr->btf_vmlinux_value_type_id) { - if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS || - attr->btf_key_type_id || attr->btf_value_type_id) + if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS) { + bpf_log(log, "btf_vmlinux_value_type_id can only be used with struct_ops maps.\n"); return -EINVAL; + } + if (attr->btf_key_type_id || attr->btf_value_type_id) { + bpf_log(log, "btf_vmlinux_value_type_id is mutually exclusive with btf_key_type_id and btf_value_type_id.\n"); + return -EINVAL; + } } else if (attr->btf_key_type_id && !attr->btf_value_type_id) { + bpf_log(log, "Invalid btf_value_type_id.\n"); return -EINVAL; } if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER && attr->map_type != BPF_MAP_TYPE_ARENA && - attr->map_extra != 0) + attr->map_extra != 0) { + bpf_log(log, "Invalid map_extra.\n"); return -EINVAL; + } f_flags = bpf_get_file_flag(attr->map_flags); if (f_flags < 0) @@ -1399,13 +1409,17 @@ static int map_create(union bpf_attr *attr, bpfptr_t uattr) if (numa_node != NUMA_NO_NODE && ((unsigned int)numa_node >= nr_node_ids || - !node_online(numa_node))) + !node_online(numa_node))) { + bpf_log(log, "Invalid numa_node.\n"); return -EINVAL; + } /* find map type and init map: hashtable vs rbtree vs bloom vs ... */ map_type = attr->map_type; - if (map_type >= ARRAY_SIZE(bpf_map_types)) + if (map_type >= ARRAY_SIZE(bpf_map_types)) { + bpf_log(log, "Invalid map_type.\n"); return -EINVAL; + } map_type = array_index_nospec(map_type, ARRAY_SIZE(bpf_map_types)); ops = bpf_map_types[map_type]; if (!ops) @@ -1423,8 +1437,10 @@ static int map_create(union bpf_attr *attr, bpfptr_t uattr) if (token_flag) { token = bpf_token_get_from_fd(attr->map_token_fd); - if (IS_ERR(token)) + if (IS_ERR(token)) { + bpf_log(log, "Invalid map_token_fd.\n"); return PTR_ERR(token); + } /* if current token doesn't grant map creation permissions, * then we can't use this token, so ignore it and rely on @@ -1507,8 +1523,10 @@ static int map_create(union bpf_attr *attr, bpfptr_t uattr) err = bpf_obj_name_cpy(map->name, attr->map_name, sizeof(attr->map_name)); - if (err < 0) + if (err < 0) { + bpf_log(log, "Invalid map_name.\n"); goto free_map; + } preempt_disable(); map->cookie = gen_cookie_next(&bpf_map_cookie); @@ -1531,6 +1549,7 @@ static int map_create(union bpf_attr *attr, bpfptr_t uattr) btf = btf_get_by_fd(attr->btf_fd); if (IS_ERR(btf)) { + bpf_log(log, "Invalid btf_fd.\n"); err = PTR_ERR(btf); goto free_map; } @@ -1558,6 +1577,7 @@ static int map_create(union bpf_attr *attr, bpfptr_t uattr) bpfptr_t uprog_hash = make_bpfptr(attr->excl_prog_hash, uattr.is_kernel); if (attr->excl_prog_hash_size != SHA256_DIGEST_SIZE) { + bpf_log(log, "Invalid excl_prog_hash_size.\n"); err = -EINVAL; goto free_map; } @@ -1573,6 +1593,7 @@ static int map_create(union bpf_attr *attr, bpfptr_t uattr) goto free_map; } } else if (attr->excl_prog_hash_size) { + bpf_log(log, "Invalid excl_prog_hash_size.\n"); err = -EINVAL; goto free_map; } @@ -1611,6 +1632,31 @@ put_token: return err; } +static int map_create(union bpf_attr *attr, bpfptr_t uattr, struct bpf_common_attr *attr_common, + bpfptr_t uattr_common, u32 size_common) +{ + struct bpf_verifier_log *log; + struct bpf_log_attr attr_log; + int err, ret; + + log = bpf_log_attr_create_vlog(&attr_log, attr_common, uattr_common, size_common); + if (IS_ERR(log)) + return PTR_ERR(log); + + err = __map_create(attr, uattr, log); + + /* preserve original error even if log finalization is successful */ + ret = bpf_log_attr_finalize(&attr_log, log); + if (ret) { + if (err >= 0) + close_fd(err); + err = ret; + } + + kfree(log); + return err; +} + void bpf_map_inc(struct bpf_map *map) { atomic64_inc(&map->refcnt); @@ -6250,7 +6296,7 @@ static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size, switch (cmd) { case BPF_MAP_CREATE: - err = map_create(&attr, uattr); + err = map_create(&attr, uattr, &attr_common, uattr_common, size_common); break; case BPF_MAP_LOOKUP_ELEM: err = map_lookup_elem(&attr); -- cgit v1.2.3