From 8a60a041eada0fbfdc7b6b7a10fdf68ae6a840ce Mon Sep 17 00:00:00 2001 From: Kui-Feng Lee Date: Thu, 3 Aug 2023 17:51:01 -0700 Subject: bpf: fix inconsistent return types of bpf_xdp_copy_buf(). Fix inconsistent return types in two implementations of bpf_xdp_copy_buf(). There are two implementations: one is an empty implementation whose return type does not match the actual implementation. Suggested-by: Alexei Starovoitov Signed-off-by: Kui-Feng Lee Acked-by: Yonghong Song Link: https://lore.kernel.org/r/20230804005101.1534505-1-thinker.li@gmail.com Signed-off-by: Martin KaFai Lau --- include/linux/filter.h | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/include/linux/filter.h b/include/linux/filter.h index 2d6fe30bad5f..761af6b3cf2b 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -1572,10 +1572,9 @@ static inline void *bpf_xdp_pointer(struct xdp_buff *xdp, u32 offset, u32 len) return NULL; } -static inline void *bpf_xdp_copy_buf(struct xdp_buff *xdp, unsigned long off, void *buf, - unsigned long len, bool flush) +static inline void bpf_xdp_copy_buf(struct xdp_buff *xdp, unsigned long off, void *buf, + unsigned long len, bool flush) { - return NULL; } #endif /* CONFIG_NET */ -- cgit v1.2.3 From a3c485a5d8d47af5d2d1a0e5c3b7a1ed223669f9 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Mon, 7 Aug 2023 10:59:54 +0200 Subject: bpf: Add support for bpf_get_func_ip helper for uprobe program Adding support for bpf_get_func_ip helper for uprobe program to return probed address for both uprobe and return uprobe. We discussed this in [1] and agreed that uprobe can have special use of bpf_get_func_ip helper that differs from kprobe. The kprobe bpf_get_func_ip returns: - address of the function if probe is attach on function entry for both kprobe and return kprobe - 0 if the probe is not attach on function entry The uprobe bpf_get_func_ip returns: - address of the probe for both uprobe and return uprobe The reason for this semantic change is that kernel can't really tell if the probe user space address is function entry. The uprobe program is actually kprobe type program attached as uprobe. One of the consequences of this design is that uprobes do not have its own set of helpers, but share them with kprobes. As we need different functionality for bpf_get_func_ip helper for uprobe, I'm adding the bool value to the bpf_trace_run_ctx, so the helper can detect that it's executed in uprobe context and call specific code. The is_uprobe bool is set as true in bpf_prog_run_array_sleepable, which is currently used only for executing bpf programs in uprobe. Renaming bpf_prog_run_array_sleepable to bpf_prog_run_array_uprobe to address that it's only used for uprobes and that it sets the run_ctx.is_uprobe as suggested by Yafang Shao. Suggested-by: Andrii Nakryiko Tested-by: Alan Maguire [1] https://lore.kernel.org/bpf/CAEf4BzZ=xLVkG5eurEuvLU79wAMtwho7ReR+XJAgwhFF4M-7Cg@mail.gmail.com/ Signed-off-by: Jiri Olsa Tested-by: Viktor Malik Acked-by: Yonghong Song Link: https://lore.kernel.org/r/20230807085956.2344866-2-jolsa@kernel.org Signed-off-by: Martin KaFai Lau --- include/linux/bpf.h | 9 +++++++-- include/uapi/linux/bpf.h | 7 ++++++- 2 files changed, 13 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index abe75063630b..db3fe5a61b05 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1819,6 +1819,7 @@ struct bpf_cg_run_ctx { struct bpf_trace_run_ctx { struct bpf_run_ctx run_ctx; u64 bpf_cookie; + bool is_uprobe; }; struct bpf_tramp_run_ctx { @@ -1867,6 +1868,8 @@ bpf_prog_run_array(const struct bpf_prog_array *array, if (unlikely(!array)) return ret; + run_ctx.is_uprobe = false; + migrate_disable(); old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); item = &array->items[0]; @@ -1891,8 +1894,8 @@ bpf_prog_run_array(const struct bpf_prog_array *array, * rcu-protected dynamically sized maps. */ static __always_inline u32 -bpf_prog_run_array_sleepable(const struct bpf_prog_array __rcu *array_rcu, - const void *ctx, bpf_prog_run_fn run_prog) +bpf_prog_run_array_uprobe(const struct bpf_prog_array __rcu *array_rcu, + const void *ctx, bpf_prog_run_fn run_prog) { const struct bpf_prog_array_item *item; const struct bpf_prog *prog; @@ -1906,6 +1909,8 @@ bpf_prog_run_array_sleepable(const struct bpf_prog_array __rcu *array_rcu, rcu_read_lock_trace(); migrate_disable(); + run_ctx.is_uprobe = true; + array = rcu_dereference_check(array_rcu, rcu_read_lock_trace_held()); if (unlikely(!array)) goto out; diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 70da85200695..d21deb46f49f 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -5086,9 +5086,14 @@ union bpf_attr { * u64 bpf_get_func_ip(void *ctx) * Description * Get address of the traced function (for tracing and kprobe programs). + * + * When called for kprobe program attached as uprobe it returns + * probe address for both entry and return uprobe. + * * Return - * Address of the traced function. + * Address of the traced function for kprobe. * 0 for kprobes placed within the function (not at the entry). + * Address of the probe for uprobe and return uprobe. * * u64 bpf_get_attach_cookie(void *ctx) * Description -- cgit v1.2.3 From 2adbb7637fd1fcec93f4680ddb5ddbbd1a91aefb Mon Sep 17 00:00:00 2001 From: Yue Haibing Date: Tue, 8 Aug 2023 22:57:41 +0800 Subject: bpf: btf: Remove two unused function declarations Commit db559117828d ("bpf: Consolidate spin_lock, timer management into btf_record") removed the implementations but leave declarations. Signed-off-by: Yue Haibing Link: https://lore.kernel.org/r/20230808145741.33292-1-yuehaibing@huawei.com Signed-off-by: Martin KaFai Lau --- include/linux/btf.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include') diff --git a/include/linux/btf.h b/include/linux/btf.h index cac9f304e27a..df64cc642074 100644 --- a/include/linux/btf.h +++ b/include/linux/btf.h @@ -204,8 +204,6 @@ u32 btf_nr_types(const struct btf *btf); bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s, const struct btf_member *m, u32 expected_offset, u32 expected_size); -int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t); -int btf_find_timer(const struct btf *btf, const struct btf_type *t); struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type *t, u32 field_mask, u32 value_size); int btf_check_and_fixup_fields(const struct btf *btf, struct btf_record *rec); -- cgit v1.2.3