perf augmented_raw_syscalls: Introduce helper to get the scratch space

We need more than the BPF stack can give us to format the
raw_syscalls:sys_enter augmented tracepoint, so we use a PERCPU_ARRAY
map for that, use a helper to shorten the sequence to access that area.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Arnaldo Carvalho de Melo 2019-08-23 15:45:54 -03:00
parent 01128065ca
commit c265784de7

View File

@ -78,8 +78,15 @@ struct augmented_args_payload {
};
};
// We need more tmp space than the BPF stack can give us
bpf_map(augmented_args_tmp, PERCPU_ARRAY, int, struct augmented_args_payload, 1);
static inline struct augmented_args_payload *augmented_args_payload(void)
{
int key = 0;
return bpf_map_lookup_elem(&augmented_args_tmp, &key);
}
static inline
unsigned int augmented_arg__read_str(struct augmented_arg *augmented_arg, const void *arg, unsigned int arg_len)
{
@ -122,8 +129,7 @@ int syscall_unaugmented(struct syscall_enter_args *args)
SEC("!syscalls:sys_enter_connect")
int sys_enter_connect(struct syscall_enter_args *args)
{
int key = 0;
struct augmented_args_payload *augmented_args = bpf_map_lookup_elem(&augmented_args_tmp, &key);
struct augmented_args_payload *augmented_args = augmented_args_payload();
const void *sockaddr_arg = (const void *)args->args[1];
unsigned int socklen = args->args[2];
unsigned int len = sizeof(augmented_args->args);
@ -143,8 +149,7 @@ int sys_enter_connect(struct syscall_enter_args *args)
SEC("!syscalls:sys_enter_sendto")
int sys_enter_sendto(struct syscall_enter_args *args)
{
int key = 0;
struct augmented_args_payload *augmented_args = bpf_map_lookup_elem(&augmented_args_tmp, &key);
struct augmented_args_payload *augmented_args = augmented_args_payload();
const void *sockaddr_arg = (const void *)args->args[4];
unsigned int socklen = args->args[5];
unsigned int len = sizeof(augmented_args->args);
@ -164,8 +169,7 @@ int sys_enter_sendto(struct syscall_enter_args *args)
SEC("!syscalls:sys_enter_open")
int sys_enter_open(struct syscall_enter_args *args)
{
int key = 0;
struct augmented_args_payload *augmented_args = bpf_map_lookup_elem(&augmented_args_tmp, &key);
struct augmented_args_payload *augmented_args = augmented_args_payload();
const void *filename_arg = (const void *)args->args[0];
unsigned int len = sizeof(augmented_args->args);
@ -181,8 +185,7 @@ int sys_enter_open(struct syscall_enter_args *args)
SEC("!syscalls:sys_enter_openat")
int sys_enter_openat(struct syscall_enter_args *args)
{
int key = 0;
struct augmented_args_payload *augmented_args = bpf_map_lookup_elem(&augmented_args_tmp, &key);
struct augmented_args_payload *augmented_args = augmented_args_payload();
const void *filename_arg = (const void *)args->args[1];
unsigned int len = sizeof(augmented_args->args);
@ -198,8 +201,7 @@ int sys_enter_openat(struct syscall_enter_args *args)
SEC("!syscalls:sys_enter_rename")
int sys_enter_rename(struct syscall_enter_args *args)
{
int key = 0;
struct augmented_args_payload *augmented_args = bpf_map_lookup_elem(&augmented_args_tmp, &key);
struct augmented_args_payload *augmented_args = augmented_args_payload();
const void *oldpath_arg = (const void *)args->args[0],
*newpath_arg = (const void *)args->args[1];
unsigned int len = sizeof(augmented_args->args), oldpath_len;
@ -217,8 +219,7 @@ int sys_enter_rename(struct syscall_enter_args *args)
SEC("!syscalls:sys_enter_renameat")
int sys_enter_renameat(struct syscall_enter_args *args)
{
int key = 0;
struct augmented_args_payload *augmented_args = bpf_map_lookup_elem(&augmented_args_tmp, &key);
struct augmented_args_payload *augmented_args = augmented_args_payload();
const void *oldpath_arg = (const void *)args->args[1],
*newpath_arg = (const void *)args->args[3];
unsigned int len = sizeof(augmented_args->args), oldpath_len;
@ -248,14 +249,13 @@ int sys_enter(struct syscall_enter_args *args)
*/
unsigned int len = sizeof(augmented_args->args);
struct syscall *syscall;
int key = 0;
if (pid_filter__has(&pids_filtered, getpid()))
return 0;
augmented_args = bpf_map_lookup_elem(&augmented_args_tmp, &key);
if (augmented_args == NULL)
return 1;
augmented_args = augmented_args_payload();
if (augmented_args == NULL)
return 1;
probe_read(&augmented_args->args, sizeof(augmented_args->args), args);