mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-24 08:04:06 +07:00
d9838d8653
Add new cmdline setups: - noprocmm - noptracefaultinfo In case of testing, they can be used to switch off usage of /proc/mm and PTRACE_FAULTINFO independently. Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
354 lines
9.0 KiB
C
354 lines
9.0 KiB
C
/*
|
|
* Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
|
|
* Licensed under the GPL
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <unistd.h>
|
|
#include <signal.h>
|
|
#include <sched.h>
|
|
#include <errno.h>
|
|
#include <stdarg.h>
|
|
#include <stdlib.h>
|
|
#include <setjmp.h>
|
|
#include <sys/time.h>
|
|
#include <sys/wait.h>
|
|
#include <sys/mman.h>
|
|
#include <asm/unistd.h>
|
|
#include <asm/page.h>
|
|
#include "user_util.h"
|
|
#include "kern_util.h"
|
|
#include "user.h"
|
|
#include "signal_kern.h"
|
|
#include "signal_user.h"
|
|
#include "sysdep/ptrace.h"
|
|
#include "sysdep/sigcontext.h"
|
|
#include "irq_user.h"
|
|
#include "ptrace_user.h"
|
|
#include "time_user.h"
|
|
#include "init.h"
|
|
#include "os.h"
|
|
#include "uml-config.h"
|
|
#include "choose-mode.h"
|
|
#include "mode.h"
|
|
#include "tempfile.h"
|
|
#ifdef UML_CONFIG_MODE_SKAS
|
|
#include "skas.h"
|
|
#include "skas_ptrace.h"
|
|
#include "registers.h"
|
|
#endif
|
|
|
|
static int ptrace_child(void *arg)
|
|
{
|
|
int ret;
|
|
int pid = os_getpid(), ppid = getppid();
|
|
int sc_result;
|
|
|
|
if(ptrace(PTRACE_TRACEME, 0, 0, 0) < 0){
|
|
perror("ptrace");
|
|
os_kill_process(pid, 0);
|
|
}
|
|
os_stop_process(pid);
|
|
|
|
/*This syscall will be intercepted by the parent. Don't call more than
|
|
* once, please.*/
|
|
sc_result = os_getpid();
|
|
|
|
if (sc_result == pid)
|
|
ret = 1; /*Nothing modified by the parent, we are running
|
|
normally.*/
|
|
else if (sc_result == ppid)
|
|
ret = 0; /*Expected in check_ptrace and check_sysemu when they
|
|
succeed in modifying the stack frame*/
|
|
else
|
|
ret = 2; /*Serious trouble! This could be caused by a bug in
|
|
host 2.6 SKAS3/2.6 patch before release -V6, together
|
|
with a bug in the UML code itself.*/
|
|
_exit(ret);
|
|
}
|
|
|
|
static int start_ptraced_child(void **stack_out)
|
|
{
|
|
void *stack;
|
|
unsigned long sp;
|
|
int pid, n, status;
|
|
|
|
stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC,
|
|
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
|
|
if(stack == MAP_FAILED)
|
|
panic("check_ptrace : mmap failed, errno = %d", errno);
|
|
sp = (unsigned long) stack + PAGE_SIZE - sizeof(void *);
|
|
pid = clone(ptrace_child, (void *) sp, SIGCHLD, NULL);
|
|
if(pid < 0)
|
|
panic("start_ptraced_child : clone failed, errno = %d", errno);
|
|
CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
|
|
if(n < 0)
|
|
panic("check_ptrace : clone failed, errno = %d", errno);
|
|
if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP))
|
|
panic("check_ptrace : expected SIGSTOP, got status = %d",
|
|
status);
|
|
|
|
*stack_out = stack;
|
|
return(pid);
|
|
}
|
|
|
|
/* When testing for SYSEMU support, if it is one of the broken versions, we
|
|
* must just avoid using sysemu, not panic, but only if SYSEMU features are
|
|
* broken.
|
|
* So only for SYSEMU features we test mustpanic, while normal host features
|
|
* must work anyway!
|
|
*/
|
|
static int stop_ptraced_child(int pid, void *stack, int exitcode,
|
|
int mustpanic)
|
|
{
|
|
int status, n, ret = 0;
|
|
|
|
if(ptrace(PTRACE_CONT, pid, 0, 0) < 0)
|
|
panic("check_ptrace : ptrace failed, errno = %d", errno);
|
|
CATCH_EINTR(n = waitpid(pid, &status, 0));
|
|
if(!WIFEXITED(status) || (WEXITSTATUS(status) != exitcode)) {
|
|
int exit_with = WEXITSTATUS(status);
|
|
if (exit_with == 2)
|
|
printk("check_ptrace : child exited with status 2. "
|
|
"Serious trouble happening! Try updating your "
|
|
"host skas patch!\nDisabling SYSEMU support.");
|
|
printk("check_ptrace : child exited with exitcode %d, while "
|
|
"expecting %d; status 0x%x", exit_with,
|
|
exitcode, status);
|
|
if (mustpanic)
|
|
panic("\n");
|
|
else
|
|
printk("\n");
|
|
ret = -1;
|
|
}
|
|
|
|
if(munmap(stack, PAGE_SIZE) < 0)
|
|
panic("check_ptrace : munmap failed, errno = %d", errno);
|
|
return ret;
|
|
}
|
|
|
|
int ptrace_faultinfo = 1;
|
|
int proc_mm = 1;
|
|
|
|
static int __init skas0_cmd_param(char *str, int* add)
|
|
{
|
|
ptrace_faultinfo = proc_mm = 0;
|
|
return 0;
|
|
}
|
|
|
|
__uml_setup("skas0", skas0_cmd_param,
|
|
"skas0\n"
|
|
" Disables SKAS3 usage, so that SKAS0 is used, unless \n"
|
|
" you specify mode=tt.\n\n");
|
|
|
|
static int force_sysemu_disabled = 0;
|
|
|
|
static int __init nosysemu_cmd_param(char *str, int* add)
|
|
{
|
|
force_sysemu_disabled = 1;
|
|
return 0;
|
|
}
|
|
|
|
__uml_setup("nosysemu", nosysemu_cmd_param,
|
|
"nosysemu\n"
|
|
" Turns off syscall emulation patch for ptrace (SYSEMU) on.\n"
|
|
" SYSEMU is a performance-patch introduced by Laurent Vivier. It changes\n"
|
|
" behaviour of ptrace() and helps reducing host context switch rate.\n"
|
|
" To make it working, you need a kernel patch for your host, too.\n"
|
|
" See http://perso.wanadoo.fr/laurent.vivier/UML/ for further \n"
|
|
" information.\n\n");
|
|
|
|
static void __init check_sysemu(void)
|
|
{
|
|
void *stack;
|
|
int pid, syscall, n, status, count=0;
|
|
|
|
printk("Checking syscall emulation patch for ptrace...");
|
|
sysemu_supported = 0;
|
|
pid = start_ptraced_child(&stack);
|
|
|
|
if(ptrace(PTRACE_SYSEMU, pid, 0, 0) < 0)
|
|
goto fail;
|
|
|
|
CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
|
|
if (n < 0)
|
|
panic("check_sysemu : wait failed, errno = %d", errno);
|
|
if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP))
|
|
panic("check_sysemu : expected SIGTRAP, "
|
|
"got status = %d", status);
|
|
|
|
n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_RET_OFFSET,
|
|
os_getpid());
|
|
if(n < 0)
|
|
panic("check_sysemu : failed to modify system "
|
|
"call return, errno = %d", errno);
|
|
|
|
if (stop_ptraced_child(pid, stack, 0, 0) < 0)
|
|
goto fail_stopped;
|
|
|
|
sysemu_supported = 1;
|
|
printk("OK\n");
|
|
set_using_sysemu(!force_sysemu_disabled);
|
|
|
|
printk("Checking advanced syscall emulation patch for ptrace...");
|
|
pid = start_ptraced_child(&stack);
|
|
while(1){
|
|
count++;
|
|
if(ptrace(PTRACE_SYSEMU_SINGLESTEP, pid, 0, 0) < 0)
|
|
goto fail;
|
|
CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
|
|
if(n < 0)
|
|
panic("check_ptrace : wait failed, errno = %d", errno);
|
|
if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP))
|
|
panic("check_ptrace : expected (SIGTRAP|SYSCALL_TRAP), "
|
|
"got status = %d", status);
|
|
|
|
syscall = ptrace(PTRACE_PEEKUSR, pid, PT_SYSCALL_NR_OFFSET,
|
|
0);
|
|
if(syscall == __NR_getpid){
|
|
if (!count)
|
|
panic("check_ptrace : SYSEMU_SINGLESTEP doesn't singlestep");
|
|
n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_RET_OFFSET,
|
|
os_getpid());
|
|
if(n < 0)
|
|
panic("check_sysemu : failed to modify system "
|
|
"call return, errno = %d", errno);
|
|
break;
|
|
}
|
|
}
|
|
if (stop_ptraced_child(pid, stack, 0, 0) < 0)
|
|
goto fail_stopped;
|
|
|
|
sysemu_supported = 2;
|
|
printk("OK\n");
|
|
|
|
if ( !force_sysemu_disabled )
|
|
set_using_sysemu(sysemu_supported);
|
|
return;
|
|
|
|
fail:
|
|
stop_ptraced_child(pid, stack, 1, 0);
|
|
fail_stopped:
|
|
printk("missing\n");
|
|
}
|
|
|
|
static void __init check_ptrace(void)
|
|
{
|
|
void *stack;
|
|
int pid, syscall, n, status;
|
|
|
|
printk("Checking that ptrace can change system call numbers...");
|
|
pid = start_ptraced_child(&stack);
|
|
|
|
if(ptrace(PTRACE_OLDSETOPTIONS, pid, 0, (void *)PTRACE_O_TRACESYSGOOD) < 0)
|
|
panic("check_ptrace: PTRACE_OLDSETOPTIONS failed, errno = %d", errno);
|
|
|
|
while(1){
|
|
if(ptrace(PTRACE_SYSCALL, pid, 0, 0) < 0)
|
|
panic("check_ptrace : ptrace failed, errno = %d",
|
|
errno);
|
|
CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
|
|
if(n < 0)
|
|
panic("check_ptrace : wait failed, errno = %d", errno);
|
|
if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP + 0x80))
|
|
panic("check_ptrace : expected SIGTRAP + 0x80, "
|
|
"got status = %d", status);
|
|
|
|
syscall = ptrace(PTRACE_PEEKUSR, pid, PT_SYSCALL_NR_OFFSET,
|
|
0);
|
|
if(syscall == __NR_getpid){
|
|
n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_NR_OFFSET,
|
|
__NR_getppid);
|
|
if(n < 0)
|
|
panic("check_ptrace : failed to modify system "
|
|
"call, errno = %d", errno);
|
|
break;
|
|
}
|
|
}
|
|
stop_ptraced_child(pid, stack, 0, 1);
|
|
printk("OK\n");
|
|
check_sysemu();
|
|
}
|
|
|
|
void os_early_checks(void)
|
|
{
|
|
check_ptrace();
|
|
}
|
|
|
|
static int __init noprocmm_cmd_param(char *str, int* add)
|
|
{
|
|
proc_mm = 0;
|
|
return 0;
|
|
}
|
|
|
|
__uml_setup("noprocmm", noprocmm_cmd_param,
|
|
"noprocmm\n"
|
|
" Turns off usage of /proc/mm, even if host supports it.\n"
|
|
" To support /proc/mm, the host needs to be patched using\n"
|
|
" the current skas3 patch.\n\n");
|
|
|
|
static int __init noptracefaultinfo_cmd_param(char *str, int* add)
|
|
{
|
|
ptrace_faultinfo = 0;
|
|
return 0;
|
|
}
|
|
|
|
__uml_setup("noptracefaultinfo", noptracefaultinfo_cmd_param,
|
|
"noptracefaultinfo\n"
|
|
" Turns off usage of PTRACE_FAULTINFO, even if host supports\n"
|
|
" it. To support PTRACE_FAULTINFO, the host needs to be patched\n"
|
|
" using the current skas3 patch.\n\n");
|
|
|
|
#ifdef UML_CONFIG_MODE_SKAS
|
|
static inline void check_skas3_ptrace_support(void)
|
|
{
|
|
struct ptrace_faultinfo fi;
|
|
void *stack;
|
|
int pid, n;
|
|
|
|
printf("Checking for the skas3 patch in the host...");
|
|
pid = start_ptraced_child(&stack);
|
|
|
|
n = ptrace(PTRACE_FAULTINFO, pid, 0, &fi);
|
|
if (n < 0) {
|
|
ptrace_faultinfo = 0;
|
|
if(errno == EIO)
|
|
printf("not found\n");
|
|
else
|
|
perror("not found");
|
|
}
|
|
else {
|
|
if (!ptrace_faultinfo)
|
|
printf("found but disabled on command line\n");
|
|
else
|
|
printf("found\n");
|
|
}
|
|
|
|
init_registers(pid);
|
|
stop_ptraced_child(pid, stack, 1, 1);
|
|
}
|
|
|
|
int can_do_skas(void)
|
|
{
|
|
printf("Checking for /proc/mm...");
|
|
if (os_access("/proc/mm", OS_ACC_W_OK) < 0) {
|
|
proc_mm = 0;
|
|
printf("not found\n");
|
|
}
|
|
else {
|
|
if (!proc_mm)
|
|
printf("found but disabled on command line\n");
|
|
else
|
|
printf("found\n");
|
|
}
|
|
|
|
check_skas3_ptrace_support();
|
|
return 1;
|
|
}
|
|
#else
|
|
int can_do_skas(void)
|
|
{
|
|
return(0);
|
|
}
|
|
#endif
|