Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
"Misc fixes:
- early_idt_handlers[] fix that fixes the build with bleeding edge
tooling
- build warning fix on GCC 5.1
- vm86 fix plus self-test to make it harder to break it again"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/asm/irq: Stop relying on magic JMP behavior for early_idt_handlers
x86/asm/entry/32, selftests: Add a selftest for kernel entries from VM86 mode
x86/boot: Add CONFIG_PARAVIRT_SPINLOCKS quirk to arch/x86/boot/compressed/misc.h
x86/asm/entry/32: Really make user_mode() work correctly for VM86 mode
hifive-unleashed-5.1
Linus Torvalds
commit
51d0f0cb3a
|
|
@ -2,15 +2,14 @@
|
|||
#define BOOT_COMPRESSED_MISC_H
|
||||
|
||||
/*
|
||||
* we have to be careful, because no indirections are allowed here, and
|
||||
* paravirt_ops is a kind of one. As it will only run in baremetal anyway,
|
||||
* we just keep it from happening
|
||||
* Special hack: we have to be careful, because no indirections are allowed here,
|
||||
* and paravirt_ops is a kind of one. As it will only run in baremetal anyway,
|
||||
* we just keep it from happening. (This list needs to be extended when new
|
||||
* paravirt and debugging variants are added.)
|
||||
*/
|
||||
#undef CONFIG_PARAVIRT
|
||||
#undef CONFIG_PARAVIRT_SPINLOCKS
|
||||
#undef CONFIG_KASAN
|
||||
#ifdef CONFIG_X86_32
|
||||
#define _ASM_X86_DESC_H 1
|
||||
#endif
|
||||
|
||||
#include <linux/linkage.h>
|
||||
#include <linux/screen_info.h>
|
||||
|
|
|
|||
|
|
@ -107,7 +107,7 @@ static inline unsigned long regs_return_value(struct pt_regs *regs)
|
|||
static inline int user_mode(struct pt_regs *regs)
|
||||
{
|
||||
#ifdef CONFIG_X86_32
|
||||
return (regs->cs & SEGMENT_RPL_MASK) == USER_RPL;
|
||||
return ((regs->cs & SEGMENT_RPL_MASK) | (regs->flags & X86_VM_MASK)) >= USER_RPL;
|
||||
#else
|
||||
return !!(regs->cs & 3);
|
||||
#endif
|
||||
|
|
|
|||
|
|
@ -231,11 +231,21 @@
|
|||
#define TLS_SIZE (GDT_ENTRY_TLS_ENTRIES* 8)
|
||||
|
||||
#ifdef __KERNEL__
|
||||
|
||||
/*
|
||||
* early_idt_handler_array is an array of entry points referenced in the
|
||||
* early IDT. For simplicity, it's a real array with one entry point
|
||||
* every nine bytes. That leaves room for an optional 'push $0' if the
|
||||
* vector has no error code (two bytes), a 'push $vector_number' (two
|
||||
* bytes), and a jump to the common entry code (up to five bytes).
|
||||
*/
|
||||
#define EARLY_IDT_HANDLER_SIZE 9
|
||||
|
||||
#ifndef __ASSEMBLY__
|
||||
|
||||
extern const char early_idt_handlers[NUM_EXCEPTION_VECTORS][2+2+5];
|
||||
extern const char early_idt_handler_array[NUM_EXCEPTION_VECTORS][EARLY_IDT_HANDLER_SIZE];
|
||||
#ifdef CONFIG_TRACING
|
||||
# define trace_early_idt_handlers early_idt_handlers
|
||||
# define trace_early_idt_handler_array early_idt_handler_array
|
||||
#endif
|
||||
|
||||
/*
|
||||
|
|
|
|||
|
|
@ -167,7 +167,7 @@ asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data)
|
|||
clear_bss();
|
||||
|
||||
for (i = 0; i < NUM_EXCEPTION_VECTORS; i++)
|
||||
set_intr_gate(i, early_idt_handlers[i]);
|
||||
set_intr_gate(i, early_idt_handler_array[i]);
|
||||
load_idt((const struct desc_ptr *)&idt_descr);
|
||||
|
||||
copy_bootdata(__va(real_mode_data));
|
||||
|
|
|
|||
|
|
@ -478,21 +478,22 @@ is486:
|
|||
__INIT
|
||||
setup_once:
|
||||
/*
|
||||
* Set up a idt with 256 entries pointing to ignore_int,
|
||||
* interrupt gates. It doesn't actually load idt - that needs
|
||||
* to be done on each CPU. Interrupts are enabled elsewhere,
|
||||
* when we can be relatively sure everything is ok.
|
||||
* Set up a idt with 256 interrupt gates that push zero if there
|
||||
* is no error code and then jump to early_idt_handler_common.
|
||||
* It doesn't actually load the idt - that needs to be done on
|
||||
* each CPU. Interrupts are enabled elsewhere, when we can be
|
||||
* relatively sure everything is ok.
|
||||
*/
|
||||
|
||||
movl $idt_table,%edi
|
||||
movl $early_idt_handlers,%eax
|
||||
movl $early_idt_handler_array,%eax
|
||||
movl $NUM_EXCEPTION_VECTORS,%ecx
|
||||
1:
|
||||
movl %eax,(%edi)
|
||||
movl %eax,4(%edi)
|
||||
/* interrupt gate, dpl=0, present */
|
||||
movl $(0x8E000000 + __KERNEL_CS),2(%edi)
|
||||
addl $9,%eax
|
||||
addl $EARLY_IDT_HANDLER_SIZE,%eax
|
||||
addl $8,%edi
|
||||
loop 1b
|
||||
|
||||
|
|
@ -524,26 +525,28 @@ setup_once:
|
|||
andl $0,setup_once_ref /* Once is enough, thanks */
|
||||
ret
|
||||
|
||||
ENTRY(early_idt_handlers)
|
||||
ENTRY(early_idt_handler_array)
|
||||
# 36(%esp) %eflags
|
||||
# 32(%esp) %cs
|
||||
# 28(%esp) %eip
|
||||
# 24(%rsp) error code
|
||||
i = 0
|
||||
.rept NUM_EXCEPTION_VECTORS
|
||||
.if (EXCEPTION_ERRCODE_MASK >> i) & 1
|
||||
ASM_NOP2
|
||||
.else
|
||||
.ifeq (EXCEPTION_ERRCODE_MASK >> i) & 1
|
||||
pushl $0 # Dummy error code, to make stack frame uniform
|
||||
.endif
|
||||
pushl $i # 20(%esp) Vector number
|
||||
jmp early_idt_handler
|
||||
jmp early_idt_handler_common
|
||||
i = i + 1
|
||||
.fill early_idt_handler_array + i*EARLY_IDT_HANDLER_SIZE - ., 1, 0xcc
|
||||
.endr
|
||||
ENDPROC(early_idt_handlers)
|
||||
ENDPROC(early_idt_handler_array)
|
||||
|
||||
/* This is global to keep gas from relaxing the jumps */
|
||||
ENTRY(early_idt_handler)
|
||||
early_idt_handler_common:
|
||||
/*
|
||||
* The stack is the hardware frame, an error code or zero, and the
|
||||
* vector number.
|
||||
*/
|
||||
cld
|
||||
|
||||
cmpl $2,(%esp) # X86_TRAP_NMI
|
||||
|
|
@ -603,7 +606,7 @@ ex_entry:
|
|||
is_nmi:
|
||||
addl $8,%esp /* drop vector number and error code */
|
||||
iret
|
||||
ENDPROC(early_idt_handler)
|
||||
ENDPROC(early_idt_handler_common)
|
||||
|
||||
/* This is the default interrupt "handler" :-) */
|
||||
ALIGN
|
||||
|
|
|
|||
|
|
@ -321,26 +321,28 @@ bad_address:
|
|||
jmp bad_address
|
||||
|
||||
__INIT
|
||||
.globl early_idt_handlers
|
||||
early_idt_handlers:
|
||||
ENTRY(early_idt_handler_array)
|
||||
# 104(%rsp) %rflags
|
||||
# 96(%rsp) %cs
|
||||
# 88(%rsp) %rip
|
||||
# 80(%rsp) error code
|
||||
i = 0
|
||||
.rept NUM_EXCEPTION_VECTORS
|
||||
.if (EXCEPTION_ERRCODE_MASK >> i) & 1
|
||||
ASM_NOP2
|
||||
.else
|
||||
.ifeq (EXCEPTION_ERRCODE_MASK >> i) & 1
|
||||
pushq $0 # Dummy error code, to make stack frame uniform
|
||||
.endif
|
||||
pushq $i # 72(%rsp) Vector number
|
||||
jmp early_idt_handler
|
||||
jmp early_idt_handler_common
|
||||
i = i + 1
|
||||
.fill early_idt_handler_array + i*EARLY_IDT_HANDLER_SIZE - ., 1, 0xcc
|
||||
.endr
|
||||
ENDPROC(early_idt_handler_array)
|
||||
|
||||
/* This is global to keep gas from relaxing the jumps */
|
||||
ENTRY(early_idt_handler)
|
||||
early_idt_handler_common:
|
||||
/*
|
||||
* The stack is the hardware frame, an error code or zero, and the
|
||||
* vector number.
|
||||
*/
|
||||
cld
|
||||
|
||||
cmpl $2,(%rsp) # X86_TRAP_NMI
|
||||
|
|
@ -412,7 +414,7 @@ ENTRY(early_idt_handler)
|
|||
is_nmi:
|
||||
addq $16,%rsp # drop vector number and error code
|
||||
INTERRUPT_RETURN
|
||||
ENDPROC(early_idt_handler)
|
||||
ENDPROC(early_idt_handler_common)
|
||||
|
||||
__INITDATA
|
||||
|
||||
|
|
|
|||
|
|
@ -5,8 +5,10 @@ include ../lib.mk
|
|||
.PHONY: all all_32 all_64 warn_32bit_failure clean
|
||||
|
||||
TARGETS_C_BOTHBITS := sigreturn single_step_syscall
|
||||
TARGETS_C_32BIT_ONLY := entry_from_vm86
|
||||
|
||||
BINARIES_32 := $(TARGETS_C_BOTHBITS:%=%_32)
|
||||
TARGETS_C_32BIT_ALL := $(TARGETS_C_BOTHBITS) $(TARGETS_C_32BIT_ONLY)
|
||||
BINARIES_32 := $(TARGETS_C_32BIT_ALL:%=%_32)
|
||||
BINARIES_64 := $(TARGETS_C_BOTHBITS:%=%_64)
|
||||
|
||||
CFLAGS := -O2 -g -std=gnu99 -pthread -Wall
|
||||
|
|
@ -32,7 +34,7 @@ all_64: $(BINARIES_64)
|
|||
clean:
|
||||
$(RM) $(BINARIES_32) $(BINARIES_64)
|
||||
|
||||
$(TARGETS_C_BOTHBITS:%=%_32): %_32: %.c
|
||||
$(TARGETS_C_32BIT_ALL:%=%_32): %_32: %.c
|
||||
$(CC) -m32 -o $@ $(CFLAGS) $(EXTRA_CFLAGS) $^ -lrt -ldl
|
||||
|
||||
$(TARGETS_C_BOTHBITS:%=%_64): %_64: %.c
|
||||
|
|
|
|||
|
|
@ -0,0 +1,114 @@
|
|||
/*
|
||||
* entry_from_vm86.c - tests kernel entries from vm86 mode
|
||||
* Copyright (c) 2014-2015 Andrew Lutomirski
|
||||
*
|
||||
* This exercises a few paths that need to special-case vm86 mode.
|
||||
*
|
||||
* GPL v2.
|
||||
*/
|
||||
|
||||
#define _GNU_SOURCE
|
||||
|
||||
#include <assert.h>
|
||||
#include <stdlib.h>
|
||||
#include <sys/syscall.h>
|
||||
#include <sys/signal.h>
|
||||
#include <sys/ucontext.h>
|
||||
#include <unistd.h>
|
||||
#include <stdio.h>
|
||||
#include <string.h>
|
||||
#include <inttypes.h>
|
||||
#include <sys/mman.h>
|
||||
#include <err.h>
|
||||
#include <stddef.h>
|
||||
#include <stdbool.h>
|
||||
#include <errno.h>
|
||||
#include <sys/vm86.h>
|
||||
|
||||
static unsigned long load_addr = 0x10000;
|
||||
static int nerrs = 0;
|
||||
|
||||
asm (
|
||||
".pushsection .rodata\n\t"
|
||||
".type vmcode_bound, @object\n\t"
|
||||
"vmcode:\n\t"
|
||||
"vmcode_bound:\n\t"
|
||||
".code16\n\t"
|
||||
"bound %ax, (2048)\n\t"
|
||||
"int3\n\t"
|
||||
"vmcode_sysenter:\n\t"
|
||||
"sysenter\n\t"
|
||||
".size vmcode, . - vmcode\n\t"
|
||||
"end_vmcode:\n\t"
|
||||
".code32\n\t"
|
||||
".popsection"
|
||||
);
|
||||
|
||||
extern unsigned char vmcode[], end_vmcode[];
|
||||
extern unsigned char vmcode_bound[], vmcode_sysenter[];
|
||||
|
||||
static void do_test(struct vm86plus_struct *v86, unsigned long eip,
|
||||
const char *text)
|
||||
{
|
||||
long ret;
|
||||
|
||||
printf("[RUN]\t%s from vm86 mode\n", text);
|
||||
v86->regs.eip = eip;
|
||||
ret = vm86(VM86_ENTER, v86);
|
||||
|
||||
if (ret == -1 && errno == ENOSYS) {
|
||||
printf("[SKIP]\tvm86 not supported\n");
|
||||
return;
|
||||
}
|
||||
|
||||
if (VM86_TYPE(ret) == VM86_INTx) {
|
||||
char trapname[32];
|
||||
int trapno = VM86_ARG(ret);
|
||||
if (trapno == 13)
|
||||
strcpy(trapname, "GP");
|
||||
else if (trapno == 5)
|
||||
strcpy(trapname, "BR");
|
||||
else if (trapno == 14)
|
||||
strcpy(trapname, "PF");
|
||||
else
|
||||
sprintf(trapname, "%d", trapno);
|
||||
|
||||
printf("[OK]\tExited vm86 mode due to #%s\n", trapname);
|
||||
} else if (VM86_TYPE(ret) == VM86_UNKNOWN) {
|
||||
printf("[OK]\tExited vm86 mode due to unhandled GP fault\n");
|
||||
} else {
|
||||
printf("[OK]\tExited vm86 mode due to type %ld, arg %ld\n",
|
||||
VM86_TYPE(ret), VM86_ARG(ret));
|
||||
}
|
||||
}
|
||||
|
||||
int main(void)
|
||||
{
|
||||
struct vm86plus_struct v86;
|
||||
unsigned char *addr = mmap((void *)load_addr, 4096,
|
||||
PROT_READ | PROT_WRITE | PROT_EXEC,
|
||||
MAP_ANONYMOUS | MAP_PRIVATE, -1,0);
|
||||
if (addr != (unsigned char *)load_addr)
|
||||
err(1, "mmap");
|
||||
|
||||
memcpy(addr, vmcode, end_vmcode - vmcode);
|
||||
addr[2048] = 2;
|
||||
addr[2050] = 3;
|
||||
|
||||
memset(&v86, 0, sizeof(v86));
|
||||
|
||||
v86.regs.cs = load_addr / 16;
|
||||
v86.regs.ss = load_addr / 16;
|
||||
v86.regs.ds = load_addr / 16;
|
||||
v86.regs.es = load_addr / 16;
|
||||
|
||||
assert((v86.regs.cs & 3) == 0); /* Looks like RPL = 0 */
|
||||
|
||||
/* #BR -- should deliver SIG??? */
|
||||
do_test(&v86, vmcode_bound - vmcode, "#BR");
|
||||
|
||||
/* SYSENTER -- should cause #GP or #UD depending on CPU */
|
||||
do_test(&v86, vmcode_sysenter - vmcode, "SYSENTER");
|
||||
|
||||
return (nerrs == 0 ? 0 : 1);
|
||||
}
|
||||
Loading…
Reference in New Issue