public-mirrors/linux
1
0
Fork 0
mirror of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-08-05 16:54:27 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

bpf: btf: Add BTF_FMODEL_SIGNED_ARG flag

Browse source 
s390x eBPF JIT needs to know whether a function return value is signed
and which function arguments are signed, in order to generate code
compliant with the s390x ABI.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/r/20230128000650.1516334-26-iii@linux.ibm.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Ilya Leoshkevich 2023-01-28 01:06:44 +01:00 • committed by Alexei Starovoitov
parent 0f0e5f5bd5
commit 49f67f393f
3 changed files with 29 additions and 6 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
include/linux/bpf.h
View file

@ -899,8 +899,12 @@ enum bpf_cgroup_storage_type {
/* The argument is a structure. */
#define BTF_FMODEL_STRUCT_ARG BIT(0)
/* The argument is signed. */
#define BTF_FMODEL_SIGNED_ARG BIT(1)
struct btf_func_model {
u8 ret_size;
u8 ret_flags;
u8 nr_args;
u8 arg_size[MAX_BPF_FUNC_ARGS];
u8 arg_flags[MAX_BPF_FUNC_ARGS];

15
include/linux/btf.h
View file

@ -236,6 +236,16 @@ 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 u8 btf_int_encoding(const struct btf_type *t)
{
return BTF_INT_ENCODING(*(u32 *)(t + 1));
}
static inline bool btf_type_is_signed_int(const struct btf_type *t)
{
return btf_type_is_int(t) && (btf_int_encoding(t) & BTF_INT_SIGNED);
}
static inline bool btf_type_is_enum(const struct btf_type *t)
{
return BTF_INFO_KIND(t->info) == BTF_KIND_ENUM;
@ -306,11 +316,6 @@ static inline u8 btf_int_offset(const struct btf_type *t)
return BTF_INT_OFFSET(*(u32 *)(t + 1));
}
static inline u8 btf_int_encoding(const struct btf_type *t)
{
return BTF_INT_ENCODING(*(u32 *)(t + 1));
}
static inline bool btf_type_is_scalar(const struct btf_type *t)
{
return btf_type_is_int(t) || btf_type_is_enum(t);

16
kernel/bpf/btf.c
View file

@ -6453,6 +6453,18 @@ static int __get_type_size(struct btf *btf, u32 btf_id,
return -EINVAL;
}
static u8 __get_type_fmodel_flags(const struct btf_type *t)
{
u8 flags = 0;
if (__btf_type_is_struct(t))
flags |= BTF_FMODEL_STRUCT_ARG;
if (btf_type_is_signed_int(t))
flags |= BTF_FMODEL_SIGNED_ARG;
return flags;
}
int btf_distill_func_proto(struct bpf_verifier_log *log,
struct btf *btf,
const struct btf_type *func,
@ -6473,6 +6485,7 @@ int btf_distill_func_proto(struct bpf_verifier_log *log,
m->arg_flags[i] = 0;
}
m->ret_size = 8;
m->ret_flags = 0;
m->nr_args = MAX_BPF_FUNC_REG_ARGS;
return 0;
}
@ -6492,6 +6505,7 @@ int btf_distill_func_proto(struct bpf_verifier_log *log,
return -EINVAL;
}
m->ret_size = ret;
m->ret_flags = __get_type_fmodel_flags(t);
for (i = 0; i < nargs; i++) {
if (i == nargs - 1 && args[i].type == 0) {
@ -6516,7 +6530,7 @@ int btf_distill_func_proto(struct bpf_verifier_log *log,
return -EINVAL;
}
m->arg_size[i] = ret;
m->arg_flags[i] = __btf_type_is_struct(t) ? BTF_FMODEL_STRUCT_ARG : 0;
m->arg_flags[i] = __get_type_fmodel_flags(t);
}
m->nr_args = nargs;
return 0;