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Diffstat (limited to '')
| -rw-r--r-- | tools/perf/examples/bpf/augmented_syscalls.c | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/tools/perf/examples/bpf/augmented_syscalls.c b/tools/perf/examples/bpf/augmented_syscalls.c new file mode 100644 index 000000000..524fdb853 --- /dev/null +++ b/tools/perf/examples/bpf/augmented_syscalls.c @@ -0,0 +1,169 @@ +// 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> + +/* bpf-output associated map */ +bpf_map(__augmented_syscalls__, PERF_EVENT_ARRAY, int, u32, __NR_CPUS__); + +struct syscall_exit_args { + unsigned long long common_tp_fields; + long syscall_nr; + long ret; +}; + +struct augmented_filename { + unsigned 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, }; \ + unsigned int len = sizeof(augmented_args); \ + 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); \ + if (augmented_args.filename.size < sizeof(augmented_args.filename.value)) { \ + len -= sizeof(augmented_args.filename.value) - augmented_args.filename.size; \ + len &= sizeof(augmented_args.filename.value) - 1; \ + } \ + /* If perf_event_output fails, return non-zero so that it gets recorded unaugmented */ \ + return perf_event_output(args, &__augmented_syscalls__, BPF_F_CURRENT_CPU, \ + &augmented_args, len); \ +} \ +int syscall_exit(syscall)(struct syscall_exit_args *args) \ +{ \ + return 1; /* 0 as soon as we start copying data returned by the kernel, e.g. 'read' */ \ +} + +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); \ + /* If perf_event_output fails, return non-zero so that it gets recorded unaugmented */ \ + return perf_event_output(args, &__augmented_syscalls__, BPF_F_CURRENT_CPU, \ + &augmented_args, \ + sizeof(augmented_args) - sizeof(augmented_args.addr) + addrlen);\ +} \ +int syscall_exit(syscall)(struct syscall_exit_args *args) \ +{ \ + return 1; /* 0 as soon as we start copying data returned by the kernel, e.g. 'read' */ \ +} + +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); |