cosmopolitan/libc/runtime/ftracer.c
Jōshin 6e6fc38935
Apply clang-format update to repo (#1154)
Commit bc6c183 introduced a bunch of discrepancies between what files
look like in the repo and what clang-format says they should look like.
However, there were already a few discrepancies prior to that. Most of
these discrepancies seemed to be unintentional, but a few of them were
load-bearing (e.g., a #include that violated header ordering needing
something to have been #defined by a 'later' #include.)

I opted to take what I hope is a relatively smooth-brained approach: I
reverted the .clang-format change, ran clang-format on the whole repo,
reapplied the .clang-format change, reran clang-format again, and then
reverted the commit that contained the first run. Thus the full effect
of this PR should only be to apply the changed formatting rules to the
repo, and from skimming the results, this seems to be the case.

My work can be checked by applying the short, manual commits, and then
rerunning the command listed in the autogenerated commits (those whose
messages I have prefixed auto:) and seeing if your results agree.

It might be that the other diffs should be fixed at some point but I'm
leaving that aside for now.

fd '\.c(c|pp)?$' --print0| xargs -0 clang-format -i
2024-04-25 10:38:00 -07:00

121 lines
4.6 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/calls.h"
#include "libc/errno.h"
#include "libc/fmt/itoa.h"
#include "libc/intrin/cmpxchg.h"
#include "libc/intrin/kprintf.h"
#include "libc/macros.internal.h"
#include "libc/nexgen32e/stackframe.h"
#include "libc/runtime/internal.h"
#include "libc/runtime/runtime.h"
#include "libc/runtime/stack.h"
#include "libc/thread/posixthread.internal.h"
#include "libc/thread/thread.h"
#include "libc/thread/tls.h"
#include "libc/thread/tls2.internal.h"
/**
* @fileoverview Plain-text function call logging.
*
* Able to log ~2 million function calls per second, which is mostly
* bottlenecked by system call overhead. Log size is reasonable if piped
* into gzip.
*/
#define MAX_NESTING 512
#ifdef __x86_64__
#define DETOUR_SKEW 2
#elif defined(__aarch64__)
#define DETOUR_SKEW 8
#endif
static struct CosmoFtrace g_ftrace;
__funline int GetNestingLevelImpl(struct StackFrame *frame) {
int nesting = -2;
while (frame && !kisdangerous(frame)) {
++nesting;
frame = frame->next;
}
return MAX(0, nesting);
}
__funline int GetNestingLevel(struct CosmoFtrace *ft, struct StackFrame *sf) {
int nesting;
nesting = GetNestingLevelImpl(sf);
if (nesting < ft->ft_skew)
ft->ft_skew = nesting;
nesting -= ft->ft_skew;
return MIN(MAX_NESTING, nesting);
}
/**
* Prints name of function being called.
*
* Whenever a function is called, ftrace_hook() will be called from the
* function prologue which saves the parameter registers and calls this
* function, which is responsible for logging the function call.
*
* @see ftrace_install()
*/
privileged void ftracer(void) {
long stackuse;
uintptr_t fn, st;
struct CosmoTib *tib;
struct StackFrame *sf;
struct CosmoFtrace *ft;
struct PosixThread *pt;
sf = __builtin_frame_address(0);
st = (uintptr_t)__argv - sizeof(uintptr_t);
if (__ftrace <= 0)
return;
if (__tls_enabled) {
tib = __get_tls_privileged();
if (tib->tib_ftrace <= 0)
return;
ft = &tib->tib_ftracer;
if ((char *)sf >= tib->tib_sigstack_addr &&
(char *)sf <= tib->tib_sigstack_addr + tib->tib_sigstack_size) {
st = (uintptr_t)tib->tib_sigstack_addr + tib->tib_sigstack_size;
} else if ((pt = (struct PosixThread *)tib->tib_pthread) &&
pt->pt_attr.__stacksize) {
st = (uintptr_t)pt->pt_attr.__stackaddr + pt->pt_attr.__stacksize;
}
} else {
ft = &g_ftrace;
}
stackuse = st - (intptr_t)sf;
if (_cmpxchg(&ft->ft_once, false, true)) {
ft->ft_lastaddr = -1;
ft->ft_skew = GetNestingLevelImpl(sf);
}
if (_cmpxchg(&ft->ft_noreentry, false, true)) {
sf = sf->next;
fn = sf->addr + DETOUR_SKEW;
if (fn != ft->ft_lastaddr) {
kprintf("%rFUN %6P %6H %'18T %'*ld %*s%t\n", ftrace_stackdigs, stackuse,
GetNestingLevel(ft, sf) * 2, "", fn);
ft->ft_lastaddr = fn;
}
ft->ft_noreentry = false;
}
}