kernel_optimize_test/tools/perf/examples/bpf/augmented_syscalls.c
Arnaldo Carvalho de Melo 4c8f0a726e perf trace augmented_syscalls: Rename augmented_*_syscall__enter to just *_syscall
As we'll also hook into the syscalls:sys_exit_SYSCALL for which there
are enter hooks.

This way we'll be able to iterate the ELF file for the eBPF program,
find the syscalls that have hooks and filter them out from the general
raw_syscalls:sys_{enter,exit} tracepoint for not-yet-augmented (the ones
with pointer arguments not yet being attached to the usual syscalls
tracepoint payload) and non augmentable syscalls (syscalls without
pointer arguments).

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-cl1xyghwb1usp500354mv37h@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2018-08-30 15:52:21 -03:00

157 lines
4.4 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Augment syscalls with the contents of the pointer arguments.
*
* Test it with:
*
* perf trace -e tools/perf/examples/bpf/augmented_syscalls.c cat /etc/passwd > /dev/null
*
* It'll catch some openat syscalls related to the dynamic linked and
* the last one should be the one for '/etc/passwd'.
*
* This matches what is marshalled into the raw_syscall:sys_enter payload
* expected by the 'perf trace' beautifiers, and can be used by them, that will
* check if perf_sample->raw_data is more than what is expected for each
* syscalls:sys_{enter,exit}_SYSCALL tracepoint, uing the extra data as the
* contents of pointer arguments.
*/
#include <stdio.h>
#include <linux/socket.h>
struct bpf_map SEC("maps") __augmented_syscalls__ = {
.type = BPF_MAP_TYPE_PERF_EVENT_ARRAY,
.key_size = sizeof(int),
.value_size = sizeof(u32),
.max_entries = __NR_CPUS__,
};
struct augmented_filename {
int size;
int reserved;
char value[256];
};
#define augmented_filename_syscall(syscall) \
struct augmented_enter_##syscall##_args { \
struct syscall_enter_##syscall##_args args; \
struct augmented_filename filename; \
}; \
int syscall_enter(syscall)(struct syscall_enter_##syscall##_args *args) \
{ \
struct augmented_enter_##syscall##_args augmented_args = { .filename.reserved = 0, }; \
probe_read(&augmented_args.args, sizeof(augmented_args.args), args); \
augmented_args.filename.size = probe_read_str(&augmented_args.filename.value, \
sizeof(augmented_args.filename.value), \
args->filename_ptr); \
perf_event_output(args, &__augmented_syscalls__, BPF_F_CURRENT_CPU, \
&augmented_args, \
(sizeof(augmented_args) - sizeof(augmented_args.filename.value) + \
augmented_args.filename.size)); \
return 0; \
}
struct syscall_enter_openat_args {
unsigned long long common_tp_fields;
long syscall_nr;
long dfd;
char *filename_ptr;
long flags;
long mode;
};
augmented_filename_syscall(openat);
struct syscall_enter_open_args {
unsigned long long common_tp_fields;
long syscall_nr;
char *filename_ptr;
long flags;
long mode;
};
augmented_filename_syscall(open);
struct syscall_enter_inotify_add_watch_args {
unsigned long long common_tp_fields;
long syscall_nr;
long fd;
char *filename_ptr;
long mask;
};
augmented_filename_syscall(inotify_add_watch);
struct statbuf;
struct syscall_enter_newstat_args {
unsigned long long common_tp_fields;
long syscall_nr;
char *filename_ptr;
struct stat *statbuf;
};
augmented_filename_syscall(newstat);
#ifndef _K_SS_MAXSIZE
#define _K_SS_MAXSIZE 128
#endif
#define augmented_sockaddr_syscall(syscall) \
struct augmented_enter_##syscall##_args { \
struct syscall_enter_##syscall##_args args; \
struct sockaddr_storage addr; \
}; \
int syscall_enter(syscall)(struct syscall_enter_##syscall##_args *args) \
{ \
struct augmented_enter_##syscall##_args augmented_args; \
unsigned long addrlen = sizeof(augmented_args.addr); \
probe_read(&augmented_args.args, sizeof(augmented_args.args), args); \
/* FIXME_CLANG_OPTIMIZATION_THAT_ACCESSES_USER_CONTROLLED_ADDRLEN_DESPITE_THIS_CHECK */ \
/* if (addrlen > augmented_args.args.addrlen) */ \
/* addrlen = augmented_args.args.addrlen; */ \
/* */ \
probe_read(&augmented_args.addr, addrlen, args->addr_ptr); \
perf_event_output(args, &__augmented_syscalls__, BPF_F_CURRENT_CPU, \
&augmented_args, \
sizeof(augmented_args) - sizeof(augmented_args.addr) + addrlen); \
return 0; \
}
struct sockaddr;
struct syscall_enter_bind_args {
unsigned long long common_tp_fields;
long syscall_nr;
long fd;
struct sockaddr *addr_ptr;
unsigned long addrlen;
};
augmented_sockaddr_syscall(bind);
struct syscall_enter_connect_args {
unsigned long long common_tp_fields;
long syscall_nr;
long fd;
struct sockaddr *addr_ptr;
unsigned long addrlen;
};
augmented_sockaddr_syscall(connect);
struct syscall_enter_sendto_args {
unsigned long long common_tp_fields;
long syscall_nr;
long fd;
void *buff;
long len;
unsigned long flags;
struct sockaddr *addr_ptr;
long addr_len;
};
augmented_sockaddr_syscall(sendto);
license(GPL);