Re: [PATCH stable linux-5.10.y v1 1/8] bpf: Introduce composable reg, ret and arg types.

[Sasha Levin <sashal@kernel.org>]

[ Sasha's backport helper bot ]

Hi,

✅ All tests passed successfully. No issues detected.
No action required from the submitter.

The upstream commit SHA1 provided is correct: d639b9d13a39cf15639cbe6e8b2c43eb60148a73

WARNING: Author mismatch between patch and upstream commit:
Backport author: Puranjay Mohan<puranjay@kernel.org>
Commit author: Hao Luo<haoluo@google.com>

Status in newer kernel trees:
6.15.y | Present (exact SHA1)
6.14.y | Present (exact SHA1)
6.12.y | Present (exact SHA1)
6.6.y | Present (exact SHA1)
6.1.y | Present (exact SHA1)
5.15.y | Present (different SHA1: a76020980b9f)

Note: The patch differs from the upstream commit:
---
1:  d639b9d13a39c ! 1:  b9a913ca98c49 bpf: Introduce composable reg, ret and arg types.
    @@ Metadata
      ## Commit message ##
         bpf: Introduce composable reg, ret and arg types.
     
    +    commit d639b9d13a39cf15639cbe6e8b2c43eb60148a73 upstream.
    +
         There are some common properties shared between bpf reg, ret and arg
         values. For instance, a value may be a NULL pointer, or a pointer to
         a read-only memory. Previously, to express these properties, enumeration
    @@ Commit message
     
         Signed-off-by: Hao Luo <haoluo@google.com>
         Signed-off-by: Alexei Starovoitov <ast@kernel.org>
    +    Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
         Link: https://lore.kernel.org/bpf/20211217003152.48334-2-haoluo@google.com
    +    Cc: stable@vger.kernel.org # 5.10.x
     
      ## include/linux/bpf.h ##
     @@ include/linux/bpf.h: bool bpf_map_meta_equal(const struct bpf_map *meta0,
    @@ include/linux/bpf.h: bool bpf_map_meta_equal(const struct bpf_map *meta0,
      enum bpf_arg_type {
      	ARG_DONTCARE = 0,	/* unused argument in helper function */
     @@ include/linux/bpf.h: enum bpf_arg_type {
    - 	ARG_PTR_TO_CONST_STR,	/* pointer to a null terminated read-only string */
    - 	ARG_PTR_TO_TIMER,	/* pointer to bpf_timer */
    + 	ARG_PTR_TO_BTF_ID_SOCK_COMMON,	/* pointer to in-kernel sock_common or bpf-mirrored bpf_sock */
    + 	ARG_PTR_TO_PERCPU_BTF_ID,	/* pointer to in-kernel percpu type */
      	__BPF_ARG_TYPE_MAX,
     +
     +	/* This must be the last entry. Its purpose is to ensure the enum is
    @@ include/linux/bpf.h: enum bpf_arg_type {
      /* type of values returned from helper functions */
      enum bpf_return_type {
     @@ include/linux/bpf.h: enum bpf_return_type {
    + 	RET_PTR_TO_BTF_ID_OR_NULL,	/* returns a pointer to a btf_id or NULL */
      	RET_PTR_TO_MEM_OR_BTF_ID_OR_NULL, /* returns a pointer to a valid memory or a btf_id or NULL */
      	RET_PTR_TO_MEM_OR_BTF_ID,	/* returns a pointer to a valid memory or a btf_id */
    - 	RET_PTR_TO_BTF_ID,		/* returns a pointer to a btf_id */
     +	__BPF_RET_TYPE_MAX,
     +
     +	/* This must be the last entry. Its purpose is to ensure the enum is
    @@ include/linux/bpf.h: enum bpf_return_type {
      /* eBPF function prototype used by verifier to allow BPF_CALLs from eBPF programs
       * to in-kernel helper functions and for adjusting imm32 field in BPF_CALL
     @@ include/linux/bpf.h: enum bpf_reg_type {
    - 	PTR_TO_FUNC,		 /* reg points to a bpf program function */
    - 	PTR_TO_MAP_KEY,		 /* reg points to a map element key */
    - 	__BPF_REG_TYPE_MAX,
    + 	PTR_TO_RDWR_BUF,	 /* reg points to a read/write buffer */
    + 	PTR_TO_RDWR_BUF_OR_NULL, /* reg points to a read/write buffer or NULL */
    + 	PTR_TO_PERCPU_BTF_ID,	 /* reg points to a percpu kernel variable */
    ++	__BPF_REG_TYPE_MAX,
     +
     +	/* This must be the last entry. Its purpose is to ensure the enum is
     +	 * wide enough to hold the higher bits reserved for bpf_type_flag.
    @@ include/linux/bpf.h: enum bpf_reg_type {
     
      ## include/linux/bpf_verifier.h ##
     @@ include/linux/bpf_verifier.h: int bpf_check_attach_target(struct bpf_verifier_log *log,
    + 			    u32 btf_id,
      			    struct bpf_attach_target_info *tgt_info);
    - void bpf_free_kfunc_btf_tab(struct bpf_kfunc_btf_tab *tab);
      
     +#define BPF_BASE_TYPE_MASK	GENMASK(BPF_BASE_TYPE_BITS - 1, 0)
     +
    @@ include/linux/bpf_verifier.h: int bpf_check_attach_target(struct bpf_verifier_lo
     +{
     +	return type & ~BPF_BASE_TYPE_MASK;
     +}
    - 
    ++
      #endif /* _LINUX_BPF_VERIFIER_H */
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-5.10.y       |  Success    |  Success   |