linux/arch/x86/um/bugs_32.c
Tiwei Bie 9ffc6724a3 um: Add missing headers
This will address below -Wmissing-prototypes warnings:

arch/um/kernel/mem.c:202:8: warning: no previous prototype for ‘pgd_alloc’ [-Wmissing-prototypes]
arch/um/kernel/mem.c:215:7: warning: no previous prototype for ‘uml_kmalloc’ [-Wmissing-prototypes]
arch/um/kernel/process.c:207:6: warning: no previous prototype for ‘arch_cpu_idle’ [-Wmissing-prototypes]
arch/um/kernel/process.c:328:15: warning: no previous prototype for ‘arch_align_stack’ [-Wmissing-prototypes]
arch/um/kernel/reboot.c:45:6: warning: no previous prototype for ‘machine_restart’ [-Wmissing-prototypes]
arch/um/kernel/reboot.c:51:6: warning: no previous prototype for ‘machine_power_off’ [-Wmissing-prototypes]
arch/um/kernel/reboot.c:57:6: warning: no previous prototype for ‘machine_halt’ [-Wmissing-prototypes]
arch/um/kernel/skas/mmu.c:17:5: warning: no previous prototype for ‘init_new_context’ [-Wmissing-prototypes]
arch/um/kernel/skas/mmu.c:60:6: warning: no previous prototype for ‘destroy_context’ [-Wmissing-prototypes]
arch/um/kernel/skas/process.c:36:12: warning: no previous prototype for ‘start_uml’ [-Wmissing-prototypes]
arch/um/kernel/time.c:807:15: warning: no previous prototype for ‘calibrate_delay_is_known’ [-Wmissing-prototypes]
arch/um/kernel/tlb.c:594:6: warning: no previous prototype for ‘force_flush_all’ [-Wmissing-prototypes]
arch/x86/um/bugs_32.c:22:6: warning: no previous prototype for ‘arch_check_bugs’ [-Wmissing-prototypes]
arch/x86/um/bugs_32.c:44:6: warning: no previous prototype for ‘arch_examine_signal’ [-Wmissing-prototypes]
arch/x86/um/bugs_64.c:9:6: warning: no previous prototype for ‘arch_check_bugs’ [-Wmissing-prototypes]
arch/x86/um/bugs_64.c:13:6: warning: no previous prototype for ‘arch_examine_signal’ [-Wmissing-prototypes]
arch/x86/um/elfcore.c:10:12: warning: no previous prototype for ‘elf_core_extra_phdrs’ [-Wmissing-prototypes]
arch/x86/um/elfcore.c:15:5: warning: no previous prototype for ‘elf_core_write_extra_phdrs’ [-Wmissing-prototypes]
arch/x86/um/elfcore.c:42:5: warning: no previous prototype for ‘elf_core_write_extra_data’ [-Wmissing-prototypes]
arch/x86/um/elfcore.c:63:8: warning: no previous prototype for ‘elf_core_extra_data_size’ [-Wmissing-prototypes]
arch/x86/um/fault.c:18:5: warning: no previous prototype for ‘arch_fixup’ [-Wmissing-prototypes]
arch/x86/um/os-Linux/mcontext.c:7:6: warning: no previous prototype for ‘get_regs_from_mc’ [-Wmissing-prototypes]
arch/x86/um/os-Linux/tls.c:22:6: warning: no previous prototype for ‘check_host_supports_tls’ [-Wmissing-prototypes]

Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2024-04-22 21:46:20 +02:00

76 lines
1.8 KiB
C

/*
* Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL
*/
#include <arch.h>
#include <signal.h>
#include <kern_util.h>
#include <longjmp.h>
#include <sysdep/ptrace.h>
#include <generated/asm-offsets.h>
/* Set during early boot */
static int host_has_cmov = 1;
static jmp_buf cmov_test_return;
static void cmov_sigill_test_handler(int sig)
{
host_has_cmov = 0;
longjmp(cmov_test_return, 1);
}
void arch_check_bugs(void)
{
struct sigaction old, new;
printk(UM_KERN_INFO "Checking for host processor cmov support...");
new.sa_handler = cmov_sigill_test_handler;
/* Make sure that SIGILL is enabled after the handler longjmps back */
new.sa_flags = SA_NODEFER;
sigemptyset(&new.sa_mask);
sigaction(SIGILL, &new, &old);
if (setjmp(cmov_test_return) == 0) {
unsigned long foo = 0;
__asm__ __volatile__("cmovz %0, %1" : "=r" (foo) : "0" (foo));
printk(UM_KERN_CONT "Yes\n");
} else
printk(UM_KERN_CONT "No\n");
sigaction(SIGILL, &old, &new);
}
void arch_examine_signal(int sig, struct uml_pt_regs *regs)
{
unsigned char tmp[2];
/*
* This is testing for a cmov (0x0f 0x4x) instruction causing a
* SIGILL in init.
*/
if ((sig != SIGILL) || (get_current_pid() != 1))
return;
if (copy_from_user_proc(tmp, (void *) UPT_IP(regs), 2)) {
printk(UM_KERN_ERR "SIGILL in init, could not read "
"instructions!\n");
return;
}
if ((tmp[0] != 0x0f) || ((tmp[1] & 0xf0) != 0x40))
return;
if (host_has_cmov == 0)
printk(UM_KERN_ERR "SIGILL caused by cmov, which this "
"processor doesn't implement. Boot a filesystem "
"compiled for older processors");
else if (host_has_cmov == 1)
printk(UM_KERN_ERR "SIGILL caused by cmov, which this "
"processor claims to implement");
else
printk(UM_KERN_ERR "Bad value for host_has_cmov (%d)",
host_has_cmov);
}