From 27ed9353aec9de4277b3389c9f2b04beb6ab7622 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Wed, 31 Aug 2022 08:26:57 -0700 Subject: [PATCH] bpf: Update descriptions for helpers bpf_get_func_arg[_cnt]() Now instead of the number of arguments, the number of registers holding argument values are stored in trampoline. Update the description of bpf_get_func_arg[_cnt]() helpers. Previous programs without struct arguments should continue to work as usual. Signed-off-by: Yonghong Song Link: https://lore.kernel.org/r/20220831152657.2078805-1-yhs@fb.com Signed-off-by: Alexei Starovoitov --- include/uapi/linux/bpf.h | 9 +++++---- tools/include/uapi/linux/bpf.h | 9 +++++---- 2 files changed, 10 insertions(+), 8 deletions(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 793103b..3df78c5 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -5079,12 +5079,12 @@ union bpf_attr { * * long bpf_get_func_arg(void *ctx, u32 n, u64 *value) * Description - * Get **n**-th argument (zero based) of the traced function (for tracing programs) + * Get **n**-th argument register (zero based) of the traced function (for tracing programs) * returned in **value**. * * Return * 0 on success. - * **-EINVAL** if n >= arguments count of traced function. + * **-EINVAL** if n >= argument register count of traced function. * * long bpf_get_func_ret(void *ctx, u64 *value) * Description @@ -5097,10 +5097,11 @@ union bpf_attr { * * long bpf_get_func_arg_cnt(void *ctx) * Description - * Get number of arguments of the traced function (for tracing programs). + * Get number of registers of the traced function (for tracing programs) where + * function arguments are stored in these registers. * * Return - * The number of arguments of the traced function. + * The number of argument registers of the traced function. * * int bpf_get_retval(void) * Description diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 793103b..3df78c5 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -5079,12 +5079,12 @@ union bpf_attr { * * long bpf_get_func_arg(void *ctx, u32 n, u64 *value) * Description - * Get **n**-th argument (zero based) of the traced function (for tracing programs) + * Get **n**-th argument register (zero based) of the traced function (for tracing programs) * returned in **value**. * * Return * 0 on success. - * **-EINVAL** if n >= arguments count of traced function. + * **-EINVAL** if n >= argument register count of traced function. * * long bpf_get_func_ret(void *ctx, u64 *value) * Description @@ -5097,10 +5097,11 @@ union bpf_attr { * * long bpf_get_func_arg_cnt(void *ctx) * Description - * Get number of arguments of the traced function (for tracing programs). + * Get number of registers of the traced function (for tracing programs) where + * function arguments are stored in these registers. * * Return - * The number of arguments of the traced function. + * The number of argument registers of the traced function. * * int bpf_get_retval(void) * Description -- 2.7.4