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bpf: Enable private stack for eligible subprogs

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If private stack is used by any subprog, set that subprog
prog->aux->jits_use_priv_stack to be true so later jit can allocate
private stack for that subprog properly.

Also set env->prog->aux->jits_use_priv_stack to be true if
any subprog uses private stack. This is a use case for a
single main prog (no subprogs) to use private stack, and
also a use case for later struct-ops progs where
env->prog->aux->jits_use_priv_stack will enable recursion
check if any subprog uses private stack.

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20241112163912.2224007-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Yonghong Song 2024-11-12 08:39:12 -08:00 committed by Alexei Starovoitov
parent a76ab5731e
commit e00931c025
2 changed files with 12 additions and 0 deletions
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1
include/linux/bpf.h
View File

@ -1523,6 +1523,7 @@ struct bpf_prog_aux {
bool exception_cb;
bool exception_boundary;
bool is_extended; /* true if extended by freplace program */
bool jits_use_priv_stack;
u64 prog_array_member_cnt; /* counts how many times as member of prog_array */
struct mutex ext_mutex; /* mutex for is_extended and prog_array_member_cnt */
struct bpf_arena *arena;

11
kernel/bpf/verifier.c
View File

@ -6334,6 +6334,14 @@ static int check_max_stack_depth(struct bpf_verifier_env *env)
return ret;
}
}
for (int i = 0; i < env->subprog_cnt; i++) {
if (si[i].priv_stack_mode == PRIV_STACK_ADAPTIVE) {
env->prog->aux->jits_use_priv_stack = true;
break;
}
}
return 0;
}
@ -20274,6 +20282,9 @@ static int jit_subprogs(struct bpf_verifier_env *env)
func[i]->aux->name[0] = 'F';
func[i]->aux->stack_depth = env->subprog_info[i].stack_depth;
if (env->subprog_info[i].priv_stack_mode == PRIV_STACK_ADAPTIVE)
func[i]->aux->jits_use_priv_stack = true;
func[i]->jit_requested = 1;
func[i]->blinding_requested = prog->blinding_requested;
func[i]->aux->kfunc_tab = prog->aux->kfunc_tab;