Fix --ftrace with cosmo_dlopen()

This change ensures function call logging won't crash the process when
cosmo_dlopen() is called.
This commit is contained in:
Justine Tunney 2024-01-05 15:11:37 -08:00
parent 15548b523c
commit 2d93788ce3
No known key found for this signature in database
GPG key ID: BE714B4575D6E328
8 changed files with 35 additions and 7 deletions

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@ -291,7 +291,7 @@ static wontreturn dontinstrument void foreign_helper(void **p) {
__foreign.dlsym = p[1];
__foreign.dlclose = p[2];
__foreign.dlerror = p[3];
longjmp(__foreign.jb, 1);
_longjmp(__foreign.jb, 1);
}
static dontinline void elf_exec(const char *file, char **envp) {

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@ -28,6 +28,7 @@
.ftrace1
longjmp:
.ftrace2
_longjmp:
#ifdef __x86_64__
mov %esi,%eax
test %eax,%eax
@ -61,5 +62,5 @@ longjmp:
#error "unsupported architecture"
#endif
.endfn longjmp,globl
.alias longjmp,_longjmp
.endfn _longjmp,globl
.alias longjmp,siglongjmp

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@ -0,0 +1,26 @@
/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8 -*-│
vi: set et ft=asm ts=8 tw=8 fenc=utf-8 :vi
Copyright 2024 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/macros.internal.h"
// we can't allow ftrace here since ftrace needs tls
sys_set_tls:
mov __NR_set_tls(%rip),%eax
syscall
ret
.endfn sys_set_tls,globl

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@ -28,12 +28,13 @@
int sys_set_tls();
textstartup void __set_tls(struct CosmoTib *tib) {
// we can't allow --ftrace here because cosmo_dlopen() calls this
// function to fix the tls register, and ftrace needs it unbroken
dontinstrument textstartup void __set_tls(struct CosmoTib *tib) {
tib = __adj_tls(tib);
#ifdef __x86_64__
// ask the operating system to change the x86 segment register
if (IsWindows()) {
npassert(0 <= __tls_index && __tls_index < 64);
asm("mov\t%1,%%gs:%0" : "=m"(*((long *)0x1480 + __tls_index)) : "r"(tib));
} else if (IsFreebsd()) {
sys_set_tls(129 /*AMD64_SET_FSBASE*/, tib);

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@ -1,2 +0,0 @@
#include "libc/sysv/macros.internal.h"
.scall sys_set_tls,0x13d1490a5300309e,4095,3,165,globl,hidden

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@ -1725,6 +1725,7 @@ syscon nr __NR_ioperm 0x00ad 0x0fff 0xfff 0xfff 0xfff 0xfff 0xfff
syscon nr __NR_init_module 0x00af 0x0069 0xfff 0xfff 0xfff 0xfff 0xfff 0xfff
syscon nr __NR_delete_module 0x00b0 0x006a 0xfff 0xfff 0xfff 0xfff 0xfff 0xfff
syscon nr __NR_gettid 0x00ba 0x00b2 0x100001b 0xfff 432 299 311 0xfff # TODO(jart): thread_self_trap vs. gettid?
syscon nr __NR_set_tls 0x009e 0xfff 0x3000003 0xfff 0x00a5 0x0149 0x13d 0xfff
syscon nr __NR_readahead 0x00bb 0x00d5 0xfff 0xfff 0xfff 0xfff 0xfff 0xfff
syscon nr __NR_setxattr 0x00bc 0x0005 0x20000ec 0x00ec 0xfff 0xfff 0x177 0xfff
syscon nr __NR_fsetxattr 0x00be 0x0007 0x20000ed 0x00ed 0xfff 0xfff 0x179 0xfff

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@ -0,0 +1,2 @@
#include "libc/sysv/consts/syscon.internal.h"
.syscon nr,__NR_set_tls,0x009e,0xfff,0x3000003,0xfff,0x00a5,0x0149,0x13d,0xfff

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@ -201,7 +201,6 @@ scall sys_modify_ldt 0xfffffffffffff09a 0xfff globl # no wrapper
scall sys_pivot_root 0xfffffffffffff09b 0x029 globl hidden
#scall prctl 0xfffffffffffff09d 0x0a7 globl # wrapped manually
scall sys_arch_prctl 0x0a50a50a5ffff09e 0xfff globl hidden # sysarch() on bsd
scall sys_set_tls 0x13d1490a5300309e 0xfff globl hidden # arch_prctl on linux, sysarch on freebsd, _lwp_setprivate on netbsd, __set_tcb on openbsd, _lwp_setprivate on netbsd, thread_fast_set_cthread_self on xnu
scall sys_adjtimex 0xfffffffffffff09f 0x0ab globl # no wrapper
scall sys_swapon 0xffffff05520550a7 0x0e0 globl # no wrapper
scall sys_swapoff 0xffffff1a8ffff0a8 0x0e1 globl # no wrapper