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![Arnaldo Carvalho de Melo](/assets/img/avatar_default.png)
To make the code more compact, end result is the same: # perf trace -e /home/acme/git/perf/tools/perf/examples/bpf/augmented_syscalls.c sleep 1 0.000 ( 0.008 ms): sleep/9663 openat(dfd: CWD, filename: "/etc/ld.so.cache", flags: RDONLY|CLOEXEC) = 3 0.022 ( 0.005 ms): sleep/9663 openat(dfd: CWD, filename: "/lib64/libc.so.6", flags: RDONLY|CLOEXEC) = 3 0.226 ( 0.006 ms): sleep/9663 openat(dfd: CWD, filename: "/usr/lib/locale/locale-archive", flags: RDONLY|CLOEXEC) = 3 # Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: https://lkml.kernel.org/n/tip-23z08bgizqnbc3qdsyl7jyyg@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
169 lines
5.1 KiB
C
169 lines
5.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Augment syscalls with the contents of the pointer arguments.
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*
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* Test it with:
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*
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* perf trace -e tools/perf/examples/bpf/augmented_syscalls.c cat /etc/passwd > /dev/null
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*
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* It'll catch some openat syscalls related to the dynamic linked and
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* the last one should be the one for '/etc/passwd'.
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*
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* This matches what is marshalled into the raw_syscall:sys_enter payload
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* expected by the 'perf trace' beautifiers, and can be used by them, that will
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* check if perf_sample->raw_data is more than what is expected for each
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* syscalls:sys_{enter,exit}_SYSCALL tracepoint, uing the extra data as the
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* contents of pointer arguments.
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*/
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#include <stdio.h>
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#include <linux/socket.h>
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/* bpf-output associated map */
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bpf_map(__augmented_syscalls__, PERF_EVENT_ARRAY, int, u32, __NR_CPUS__);
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struct syscall_exit_args {
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unsigned long long common_tp_fields;
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long syscall_nr;
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long ret;
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};
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struct augmented_filename {
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unsigned int size;
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int reserved;
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char value[256];
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};
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#define augmented_filename_syscall(syscall) \
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struct augmented_enter_##syscall##_args { \
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struct syscall_enter_##syscall##_args args; \
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struct augmented_filename filename; \
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}; \
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int syscall_enter(syscall)(struct syscall_enter_##syscall##_args *args) \
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{ \
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struct augmented_enter_##syscall##_args augmented_args = { .filename.reserved = 0, }; \
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unsigned int len = sizeof(augmented_args); \
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probe_read(&augmented_args.args, sizeof(augmented_args.args), args); \
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augmented_args.filename.size = probe_read_str(&augmented_args.filename.value, \
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sizeof(augmented_args.filename.value), \
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args->filename_ptr); \
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if (augmented_args.filename.size < sizeof(augmented_args.filename.value)) { \
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len -= sizeof(augmented_args.filename.value) - augmented_args.filename.size; \
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len &= sizeof(augmented_args.filename.value) - 1; \
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} \
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/* If perf_event_output fails, return non-zero so that it gets recorded unaugmented */ \
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return perf_event_output(args, &__augmented_syscalls__, BPF_F_CURRENT_CPU, \
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&augmented_args, len); \
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} \
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int syscall_exit(syscall)(struct syscall_exit_args *args) \
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{ \
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return 1; /* 0 as soon as we start copying data returned by the kernel, e.g. 'read' */ \
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}
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struct syscall_enter_openat_args {
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unsigned long long common_tp_fields;
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long syscall_nr;
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long dfd;
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char *filename_ptr;
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long flags;
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long mode;
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};
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augmented_filename_syscall(openat);
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struct syscall_enter_open_args {
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unsigned long long common_tp_fields;
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long syscall_nr;
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char *filename_ptr;
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long flags;
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long mode;
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};
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augmented_filename_syscall(open);
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struct syscall_enter_inotify_add_watch_args {
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unsigned long long common_tp_fields;
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long syscall_nr;
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long fd;
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char *filename_ptr;
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long mask;
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};
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augmented_filename_syscall(inotify_add_watch);
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struct statbuf;
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struct syscall_enter_newstat_args {
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unsigned long long common_tp_fields;
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long syscall_nr;
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char *filename_ptr;
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struct stat *statbuf;
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};
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augmented_filename_syscall(newstat);
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#ifndef _K_SS_MAXSIZE
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#define _K_SS_MAXSIZE 128
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#endif
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#define augmented_sockaddr_syscall(syscall) \
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struct augmented_enter_##syscall##_args { \
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struct syscall_enter_##syscall##_args args; \
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struct sockaddr_storage addr; \
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}; \
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int syscall_enter(syscall)(struct syscall_enter_##syscall##_args *args) \
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{ \
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struct augmented_enter_##syscall##_args augmented_args; \
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unsigned long addrlen = sizeof(augmented_args.addr); \
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probe_read(&augmented_args.args, sizeof(augmented_args.args), args); \
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/* FIXME_CLANG_OPTIMIZATION_THAT_ACCESSES_USER_CONTROLLED_ADDRLEN_DESPITE_THIS_CHECK */ \
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/* if (addrlen > augmented_args.args.addrlen) */ \
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/* addrlen = augmented_args.args.addrlen; */ \
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/* */ \
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probe_read(&augmented_args.addr, addrlen, args->addr_ptr); \
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/* If perf_event_output fails, return non-zero so that it gets recorded unaugmented */ \
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return perf_event_output(args, &__augmented_syscalls__, BPF_F_CURRENT_CPU, \
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&augmented_args, \
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sizeof(augmented_args) - sizeof(augmented_args.addr) + addrlen);\
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} \
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int syscall_exit(syscall)(struct syscall_exit_args *args) \
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{ \
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return 1; /* 0 as soon as we start copying data returned by the kernel, e.g. 'read' */ \
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}
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struct sockaddr;
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struct syscall_enter_bind_args {
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unsigned long long common_tp_fields;
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long syscall_nr;
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long fd;
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struct sockaddr *addr_ptr;
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unsigned long addrlen;
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};
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augmented_sockaddr_syscall(bind);
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struct syscall_enter_connect_args {
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unsigned long long common_tp_fields;
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long syscall_nr;
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long fd;
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struct sockaddr *addr_ptr;
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unsigned long addrlen;
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};
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augmented_sockaddr_syscall(connect);
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struct syscall_enter_sendto_args {
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unsigned long long common_tp_fields;
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long syscall_nr;
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long fd;
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void *buff;
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long len;
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unsigned long flags;
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struct sockaddr *addr_ptr;
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long addr_len;
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};
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augmented_sockaddr_syscall(sendto);
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license(GPL);
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