mirror of
https://github.com/torvalds/linux.git
synced 2024-11-28 07:01:32 +00:00
4d39c89f0b
Fix ~124 single-word typos and a few spelling errors in the perf tooling code, accumulated over the years. Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20210321113734.GA248990@gmail.com Link: http://lore.kernel.org/lkml/20210323160915.GA61903@gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
295 lines
9.0 KiB
C
295 lines
9.0 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Augment the raw_syscalls tracepoints with the contents of the pointer arguments.
|
|
*
|
|
* Test it with:
|
|
*
|
|
* perf trace -e tools/perf/examples/bpf/augmented_raw_syscalls.c cat /etc/passwd > /dev/null
|
|
*
|
|
* This exactly matches what is marshalled into the raw_syscall:sys_enter
|
|
* payload expected by the 'perf trace' beautifiers.
|
|
*
|
|
* For now it just uses the existing tracepoint augmentation code in 'perf
|
|
* trace', in the next csets we'll hook up these with the sys_enter/sys_exit
|
|
* code that will combine entry/exit in a strace like way.
|
|
*/
|
|
|
|
#include <unistd.h>
|
|
#include <linux/limits.h>
|
|
#include <linux/socket.h>
|
|
#include <pid_filter.h>
|
|
|
|
/* bpf-output associated map */
|
|
bpf_map(__augmented_syscalls__, PERF_EVENT_ARRAY, int, u32, __NR_CPUS__);
|
|
|
|
/*
|
|
* string_args_len: one per syscall arg, 0 means not a string or don't copy it,
|
|
* PATH_MAX for copying everything, any other value to limit
|
|
* it a la 'strace -s strsize'.
|
|
*/
|
|
struct syscall {
|
|
bool enabled;
|
|
u16 string_args_len[6];
|
|
};
|
|
|
|
bpf_map(syscalls, ARRAY, int, struct syscall, 512);
|
|
|
|
/*
|
|
* What to augment at entry?
|
|
*
|
|
* Pointer arg payloads (filenames, etc) passed from userspace to the kernel
|
|
*/
|
|
bpf_map(syscalls_sys_enter, PROG_ARRAY, u32, u32, 512);
|
|
|
|
/*
|
|
* What to augment at exit?
|
|
*
|
|
* Pointer arg payloads returned from the kernel (struct stat, etc) to userspace.
|
|
*/
|
|
bpf_map(syscalls_sys_exit, PROG_ARRAY, u32, u32, 512);
|
|
|
|
struct syscall_enter_args {
|
|
unsigned long long common_tp_fields;
|
|
long syscall_nr;
|
|
unsigned long args[6];
|
|
};
|
|
|
|
struct syscall_exit_args {
|
|
unsigned long long common_tp_fields;
|
|
long syscall_nr;
|
|
long ret;
|
|
};
|
|
|
|
struct augmented_arg {
|
|
unsigned int size;
|
|
int err;
|
|
char value[PATH_MAX];
|
|
};
|
|
|
|
pid_filter(pids_filtered);
|
|
|
|
struct augmented_args_payload {
|
|
struct syscall_enter_args args;
|
|
union {
|
|
struct {
|
|
struct augmented_arg arg, arg2;
|
|
};
|
|
struct sockaddr_storage saddr;
|
|
};
|
|
};
|
|
|
|
// 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 int augmented__output(void *ctx, struct augmented_args_payload *args, int len)
|
|
{
|
|
/* If perf_event_output fails, return non-zero so that it gets recorded unaugmented */
|
|
return perf_event_output(ctx, &__augmented_syscalls__, BPF_F_CURRENT_CPU, args, len);
|
|
}
|
|
|
|
static inline
|
|
unsigned int augmented_arg__read_str(struct augmented_arg *augmented_arg, const void *arg, unsigned int arg_len)
|
|
{
|
|
unsigned int augmented_len = sizeof(*augmented_arg);
|
|
int string_len = probe_read_str(&augmented_arg->value, arg_len, arg);
|
|
|
|
augmented_arg->size = augmented_arg->err = 0;
|
|
/*
|
|
* probe_read_str may return < 0, e.g. -EFAULT
|
|
* So we leave that in the augmented_arg->size that userspace will
|
|
*/
|
|
if (string_len > 0) {
|
|
augmented_len -= sizeof(augmented_arg->value) - string_len;
|
|
augmented_len &= sizeof(augmented_arg->value) - 1;
|
|
augmented_arg->size = string_len;
|
|
} else {
|
|
/*
|
|
* So that username notice the error while still being able
|
|
* to skip this augmented arg record
|
|
*/
|
|
augmented_arg->err = string_len;
|
|
augmented_len = offsetof(struct augmented_arg, value);
|
|
}
|
|
|
|
return augmented_len;
|
|
}
|
|
|
|
SEC("!raw_syscalls:unaugmented")
|
|
int syscall_unaugmented(struct syscall_enter_args *args)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* These will be tail_called from SEC("raw_syscalls:sys_enter"), so will find in
|
|
* augmented_args_tmp what was read by that raw_syscalls:sys_enter and go
|
|
* on from there, reading the first syscall arg as a string, i.e. open's
|
|
* filename.
|
|
*/
|
|
SEC("!syscalls:sys_enter_connect")
|
|
int sys_enter_connect(struct syscall_enter_args *args)
|
|
{
|
|
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);
|
|
|
|
if (augmented_args == NULL)
|
|
return 1; /* Failure: don't filter */
|
|
|
|
if (socklen > sizeof(augmented_args->saddr))
|
|
socklen = sizeof(augmented_args->saddr);
|
|
|
|
probe_read(&augmented_args->saddr, socklen, sockaddr_arg);
|
|
|
|
return augmented__output(args, augmented_args, len + socklen);
|
|
}
|
|
|
|
SEC("!syscalls:sys_enter_sendto")
|
|
int sys_enter_sendto(struct syscall_enter_args *args)
|
|
{
|
|
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);
|
|
|
|
if (augmented_args == NULL)
|
|
return 1; /* Failure: don't filter */
|
|
|
|
if (socklen > sizeof(augmented_args->saddr))
|
|
socklen = sizeof(augmented_args->saddr);
|
|
|
|
probe_read(&augmented_args->saddr, socklen, sockaddr_arg);
|
|
|
|
return augmented__output(args, augmented_args, len + socklen);
|
|
}
|
|
|
|
SEC("!syscalls:sys_enter_open")
|
|
int sys_enter_open(struct syscall_enter_args *args)
|
|
{
|
|
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);
|
|
|
|
if (augmented_args == NULL)
|
|
return 1; /* Failure: don't filter */
|
|
|
|
len += augmented_arg__read_str(&augmented_args->arg, filename_arg, sizeof(augmented_args->arg.value));
|
|
|
|
return augmented__output(args, augmented_args, len);
|
|
}
|
|
|
|
SEC("!syscalls:sys_enter_openat")
|
|
int sys_enter_openat(struct syscall_enter_args *args)
|
|
{
|
|
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);
|
|
|
|
if (augmented_args == NULL)
|
|
return 1; /* Failure: don't filter */
|
|
|
|
len += augmented_arg__read_str(&augmented_args->arg, filename_arg, sizeof(augmented_args->arg.value));
|
|
|
|
return augmented__output(args, augmented_args, len);
|
|
}
|
|
|
|
SEC("!syscalls:sys_enter_rename")
|
|
int sys_enter_rename(struct syscall_enter_args *args)
|
|
{
|
|
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;
|
|
|
|
if (augmented_args == NULL)
|
|
return 1; /* Failure: don't filter */
|
|
|
|
oldpath_len = augmented_arg__read_str(&augmented_args->arg, oldpath_arg, sizeof(augmented_args->arg.value));
|
|
len += oldpath_len + augmented_arg__read_str((void *)(&augmented_args->arg) + oldpath_len, newpath_arg, sizeof(augmented_args->arg.value));
|
|
|
|
return augmented__output(args, augmented_args, len);
|
|
}
|
|
|
|
SEC("!syscalls:sys_enter_renameat")
|
|
int sys_enter_renameat(struct syscall_enter_args *args)
|
|
{
|
|
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;
|
|
|
|
if (augmented_args == NULL)
|
|
return 1; /* Failure: don't filter */
|
|
|
|
oldpath_len = augmented_arg__read_str(&augmented_args->arg, oldpath_arg, sizeof(augmented_args->arg.value));
|
|
len += oldpath_len + augmented_arg__read_str((void *)(&augmented_args->arg) + oldpath_len, newpath_arg, sizeof(augmented_args->arg.value));
|
|
|
|
return augmented__output(args, augmented_args, len);
|
|
}
|
|
|
|
SEC("raw_syscalls:sys_enter")
|
|
int sys_enter(struct syscall_enter_args *args)
|
|
{
|
|
struct augmented_args_payload *augmented_args;
|
|
/*
|
|
* We start len, the amount of data that will be in the perf ring
|
|
* buffer, if this is not filtered out by one of pid_filter__has(),
|
|
* syscall->enabled, etc, with the non-augmented raw syscall payload,
|
|
* i.e. sizeof(augmented_args->args).
|
|
*
|
|
* We'll add to this as we add augmented syscalls right after that
|
|
* initial, non-augmented raw_syscalls:sys_enter payload.
|
|
*/
|
|
unsigned int len = sizeof(augmented_args->args);
|
|
struct syscall *syscall;
|
|
|
|
if (pid_filter__has(&pids_filtered, getpid()))
|
|
return 0;
|
|
|
|
augmented_args = augmented_args_payload();
|
|
if (augmented_args == NULL)
|
|
return 1;
|
|
|
|
probe_read(&augmented_args->args, sizeof(augmented_args->args), args);
|
|
|
|
/*
|
|
* Jump to syscall specific augmenter, even if the default one,
|
|
* "!raw_syscalls:unaugmented" that will just return 1 to return the
|
|
* unaugmented tracepoint payload.
|
|
*/
|
|
bpf_tail_call(args, &syscalls_sys_enter, augmented_args->args.syscall_nr);
|
|
|
|
// If not found on the PROG_ARRAY syscalls map, then we're filtering it:
|
|
return 0;
|
|
}
|
|
|
|
SEC("raw_syscalls:sys_exit")
|
|
int sys_exit(struct syscall_exit_args *args)
|
|
{
|
|
struct syscall_exit_args exit_args;
|
|
|
|
if (pid_filter__has(&pids_filtered, getpid()))
|
|
return 0;
|
|
|
|
probe_read(&exit_args, sizeof(exit_args), args);
|
|
/*
|
|
* Jump to syscall specific return augmenter, even if the default one,
|
|
* "!raw_syscalls:unaugmented" that will just return 1 to return the
|
|
* unaugmented tracepoint payload.
|
|
*/
|
|
bpf_tail_call(args, &syscalls_sys_exit, exit_args.syscall_nr);
|
|
/*
|
|
* If not found on the PROG_ARRAY syscalls map, then we're filtering it:
|
|
*/
|
|
return 0;
|
|
}
|
|
|
|
license(GPL);
|