mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-30 08:02:30 +00:00
a9b59159d3
To ensure btf_ctx_access() is safe the verifier checks that the BTF
arg type is an int, enum, or pointer. When the function does the
BTF arg lookup it uses the calculation 'arg = off / 8' using the
fact that registers are 8B. This requires that the first arg is
in the first reg, the second in the second, and so on. However,
for __int128 the arg will consume two registers by default LLVM
implementation. So this will cause the arg layout assumed by the
'arg = off / 8' calculation to be incorrect.
Because __int128 is uncommon this patch applies the easiest fix and
will force int types to be sizeof(u64) or smaller so that they will
fit in a single register.
v2: remove unneeded parens per Andrii's feedback
Fixes: 9e15db6613
("bpf: Implement accurate raw_tp context access via BTF")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/159303723962.11287.13309537171132420717.stgit@john-Precision-5820-Tower
162 lines
4.8 KiB
C
162 lines
4.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
/* Copyright (c) 2018 Facebook */
|
|
|
|
#ifndef _LINUX_BTF_H
|
|
#define _LINUX_BTF_H 1
|
|
|
|
#include <linux/types.h>
|
|
#include <uapi/linux/btf.h>
|
|
|
|
#define BTF_TYPE_EMIT(type) ((void)(type *)0)
|
|
|
|
struct btf;
|
|
struct btf_member;
|
|
struct btf_type;
|
|
union bpf_attr;
|
|
|
|
extern const struct file_operations btf_fops;
|
|
|
|
void btf_put(struct btf *btf);
|
|
int btf_new_fd(const union bpf_attr *attr);
|
|
struct btf *btf_get_by_fd(int fd);
|
|
int btf_get_info_by_fd(const struct btf *btf,
|
|
const union bpf_attr *attr,
|
|
union bpf_attr __user *uattr);
|
|
/* Figure out the size of a type_id. If type_id is a modifier
|
|
* (e.g. const), it will be resolved to find out the type with size.
|
|
*
|
|
* For example:
|
|
* In describing "const void *", type_id is "const" and "const"
|
|
* refers to "void *". The return type will be "void *".
|
|
*
|
|
* If type_id is a simple "int", then return type will be "int".
|
|
*
|
|
* @btf: struct btf object
|
|
* @type_id: Find out the size of type_id. The type_id of the return
|
|
* type is set to *type_id.
|
|
* @ret_size: It can be NULL. If not NULL, the size of the return
|
|
* type is set to *ret_size.
|
|
* Return: The btf_type (resolved to another type with size info if needed).
|
|
* NULL is returned if type_id itself does not have size info
|
|
* (e.g. void) or it cannot be resolved to another type that
|
|
* has size info.
|
|
* *type_id and *ret_size will not be changed in the
|
|
* NULL return case.
|
|
*/
|
|
const struct btf_type *btf_type_id_size(const struct btf *btf,
|
|
u32 *type_id,
|
|
u32 *ret_size);
|
|
void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj,
|
|
struct seq_file *m);
|
|
int btf_get_fd_by_id(u32 id);
|
|
u32 btf_id(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);
|
|
bool btf_type_is_void(const struct btf_type *t);
|
|
s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind);
|
|
const struct btf_type *btf_type_skip_modifiers(const struct btf *btf,
|
|
u32 id, u32 *res_id);
|
|
const struct btf_type *btf_type_resolve_ptr(const struct btf *btf,
|
|
u32 id, u32 *res_id);
|
|
const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf,
|
|
u32 id, u32 *res_id);
|
|
const struct btf_type *
|
|
btf_resolve_size(const struct btf *btf, const struct btf_type *type,
|
|
u32 *type_size, const struct btf_type **elem_type,
|
|
u32 *total_nelems);
|
|
|
|
#define for_each_member(i, struct_type, member) \
|
|
for (i = 0, member = btf_type_member(struct_type); \
|
|
i < btf_type_vlen(struct_type); \
|
|
i++, member++)
|
|
|
|
static inline bool btf_type_is_ptr(const struct btf_type *t)
|
|
{
|
|
return BTF_INFO_KIND(t->info) == BTF_KIND_PTR;
|
|
}
|
|
|
|
static inline bool btf_type_is_int(const struct btf_type *t)
|
|
{
|
|
return BTF_INFO_KIND(t->info) == BTF_KIND_INT;
|
|
}
|
|
|
|
static inline bool btf_type_is_small_int(const struct btf_type *t)
|
|
{
|
|
return btf_type_is_int(t) && t->size <= sizeof(u64);
|
|
}
|
|
|
|
static inline bool btf_type_is_enum(const struct btf_type *t)
|
|
{
|
|
return BTF_INFO_KIND(t->info) == BTF_KIND_ENUM;
|
|
}
|
|
|
|
static inline bool btf_type_is_typedef(const struct btf_type *t)
|
|
{
|
|
return BTF_INFO_KIND(t->info) == BTF_KIND_TYPEDEF;
|
|
}
|
|
|
|
static inline bool btf_type_is_func(const struct btf_type *t)
|
|
{
|
|
return BTF_INFO_KIND(t->info) == BTF_KIND_FUNC;
|
|
}
|
|
|
|
static inline bool btf_type_is_func_proto(const struct btf_type *t)
|
|
{
|
|
return BTF_INFO_KIND(t->info) == BTF_KIND_FUNC_PROTO;
|
|
}
|
|
|
|
static inline u16 btf_type_vlen(const struct btf_type *t)
|
|
{
|
|
return BTF_INFO_VLEN(t->info);
|
|
}
|
|
|
|
static inline u16 btf_func_linkage(const struct btf_type *t)
|
|
{
|
|
return BTF_INFO_VLEN(t->info);
|
|
}
|
|
|
|
static inline bool btf_type_kflag(const struct btf_type *t)
|
|
{
|
|
return BTF_INFO_KFLAG(t->info);
|
|
}
|
|
|
|
static inline u32 btf_member_bit_offset(const struct btf_type *struct_type,
|
|
const struct btf_member *member)
|
|
{
|
|
return btf_type_kflag(struct_type) ? BTF_MEMBER_BIT_OFFSET(member->offset)
|
|
: member->offset;
|
|
}
|
|
|
|
static inline u32 btf_member_bitfield_size(const struct btf_type *struct_type,
|
|
const struct btf_member *member)
|
|
{
|
|
return btf_type_kflag(struct_type) ? BTF_MEMBER_BITFIELD_SIZE(member->offset)
|
|
: 0;
|
|
}
|
|
|
|
static inline const struct btf_member *btf_type_member(const struct btf_type *t)
|
|
{
|
|
return (const struct btf_member *)(t + 1);
|
|
}
|
|
|
|
#ifdef CONFIG_BPF_SYSCALL
|
|
const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id);
|
|
const char *btf_name_by_offset(const struct btf *btf, u32 offset);
|
|
struct btf *btf_parse_vmlinux(void);
|
|
struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog);
|
|
#else
|
|
static inline const struct btf_type *btf_type_by_id(const struct btf *btf,
|
|
u32 type_id)
|
|
{
|
|
return NULL;
|
|
}
|
|
static inline const char *btf_name_by_offset(const struct btf *btf,
|
|
u32 offset)
|
|
{
|
|
return NULL;
|
|
}
|
|
#endif
|
|
|
|
#endif
|