libpayload: x86: Add support for catching processor exceptions.

This functionality is already available for ARM, so lets add it to x86 as
well. We'll want to be able to hook exceptions when running as a remote GDB
target.

Change-Id: I42f640b08eb9eb86a1bcab3c327f7780191a2eb5
Signed-off-by: Gabe Black <gabeblack@google.com>
Reviewed-on: https://chromium-review.googlesource.com/179601
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: Gabe Black <gabeblack@chromium.org>
Commit-Queue: Gabe Black <gabeblack@chromium.org>
(cherry picked from commit 5b8cf0c9f70a7e14766a2b095e6739a8d6321a34)
Signed-off-by: Isaac Christensen <isaac.christensen@se-eng.com>
Reviewed-on: http://review.coreboot.org/6898
Tested-by: build bot (Jenkins)
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
This commit is contained in:
Gabe Black 2013-12-07 04:25:01 -08:00 committed by Isaac Christensen
parent 125a6a22f8
commit a799151534
6 changed files with 532 additions and 1 deletions

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@ -32,6 +32,7 @@ libc-y += main.c sysinfo.c
libc-y += timer.c coreboot.c util.S
libc-y += exec.S virtual.c
libc-y += string.c
libc-y += exception_asm.S exception.c
libcbfs-$(CONFIG_LP_CBFS) += rom_media.c

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@ -0,0 +1,199 @@
/*
* This file is part of the libpayload project.
*
* Copyright 2013 Google Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <exception.h>
#include <libpayload.h>
#include <stdint.h>
uint8_t exception_stack[0x1000] __attribute__((aligned(8)));
extern void *exception_stack_end;
struct exception_state
{
u32 eax;
u32 ecx;
u32 edx;
u32 ebx;
u32 esp;
u32 ebp;
u32 esi;
u32 edi;
u32 eip;
u32 eflags;
u32 cs;
u32 ss;
u32 ds;
u32 es;
u32 fs;
u32 gs;
u32 error_code;
u32 vector;
} __attribute__((packed));
struct exception_info
{
const char *name;
void (*error_code_printer)(u32 code);
};
static void print_segment_error_code(u32 code)
{
printf("%#x - descriptor %#x in the ", code, (code >> 3) & 0x1f);
if (code & (0x1 << 1)) {
printf("IDT");
} else {
if (code & 0x04)
printf("LDT");
else
printf("GDT");
}
if (code & (0x1 << 0))
printf(", external to the CPU");
else
printf(", internal to the CPU");
}
static void print_page_fault_error_code(u32 code)
{
printf("%#x -", code);
if (code & (0x1 << 0))
printf(" page protection");
else
printf(" page not present");
if (code & (0x1 << 1))
printf(", write");
else
printf(", read");
if (code & (0x1 << 2))
printf(", user");
else
printf(", supervisor");
if (code & (0x1 << 3))
printf(", reserved bits set");
if (code & (0x1 << 4))
printf(", instruction fetch");
}
static void print_raw_error_code(u32 code)
{
printf("%#x", code);
}
static struct exception_info exceptions[] = {
[0] = { .name = "divide by zero" },
[1] = { .name = "debug" },
[2] = { .name = "non-maskable-interrupt" },
[3] = { .name = "breakpoint" },
[4] = { .name = "overflow" },
[5] = { .name = "bound range" },
[6] = { .name = "invalid opcode" },
[7] = { .name = "device not available" },
[8] = { .name = "double fault",
.error_code_printer = &print_raw_error_code },
[10] = { .name = "invalid tss",
.error_code_printer = &print_segment_error_code },
[11] = { .name = "segment not present",
.error_code_printer = &print_segment_error_code },
[12] = { .name = "stack",
.error_code_printer = &print_segment_error_code },
[13] = { .name = "general protection",
.error_code_printer = &print_segment_error_code },
[14] = { .name = "page fault",
.error_code_printer = &print_page_fault_error_code },
[16] = { .name = "x87 floating point" },
[17] = { .name = "alignment check",
.error_code_printer = &print_raw_error_code },
[18] = { .name = "machine check" },
[19] = { .name = "SIMD floating point" },
[30] = { .name = "security",
.error_code_printer = &print_raw_error_code },
};
static void dump_stack(uintptr_t addr, size_t bytes)
{
int i, j;
const int line = 8;
uint32_t *ptr = (uint32_t *)(addr & ~(line * sizeof(*ptr) - 1));
printf("Dumping stack:\n");
for (i = bytes / sizeof(*ptr); i >= 0; i -= line) {
printf("%p: ", ptr + i);
for (j = i; j < i + line; j++)
printf("%08x ", *(ptr + j));
printf("\n");
}
}
void exception_handler(void);
void exception_handler(void)
{
struct exception_state *state =
(void *)((u8 *)exception_stack_end - sizeof(*state));
struct exception_info *info = NULL;
if (state->vector < ARRAY_SIZE(exceptions))
info = &exceptions[state->vector];
if (info)
printf("Exception %d (%s)\n", state->vector, info->name);
else
printf("Unrecognized exception %d\n", state->vector);
if (info->error_code_printer) {
printf("Error code: ");
info->error_code_printer(state->error_code);
printf("\n");
}
printf("EIP: 0x%08x\n", state->eip);
printf("CS: 0x%04x\n", state->cs);
printf("EFLAGS: 0x%08x\n", state->eflags);
printf("EAX: 0x%08x\n", state->eax);
printf("ECX: 0x%08x\n", state->ecx);
printf("EDX: 0x%08x\n", state->edx);
printf("EBX: 0x%08x\n", state->ebx);
printf("ESP: 0x%08x\n", state->esp);
printf("EBP: 0x%08x\n", state->ebp);
printf("ESI: 0x%08x\n", state->esi);
printf("EDI: 0x%08x\n", state->edi);
printf("DS: 0x%04x\n", state->ds);
printf("ES: 0x%04x\n", state->es);
printf("SS: 0x%04x\n", state->ss);
printf("FS: 0x%04x\n", state->fs);
printf("GS: 0x%04x\n", state->gs);
dump_stack(state->esp, 512);
halt();
}
void exception_init_asm(void);
void exception_init(void)
{
exception_stack_end = exception_stack + sizeof(exception_stack);
exception_init_asm();
}

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@ -0,0 +1,291 @@
/*
* This file is part of the libpayload project.
*
* Copyright 2013 Google Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
.align 4
.global exception_stack_end
exception_stack_end:
.long 0
/* Some temporary variables which are used while saving exception state. */
vector:
.long 0
error_code:
.long 0
old_esp:
.long 0
old_eax:
.long 0
.align 8
/*
* Each exception vector has a small stub associated with it which sets aside
* the error code, if any, records which vector we entered from, and calls
* the common exception entry point. Some exceptions have error codes and some
* don't, so we have a macro for each type.
*/
.macro stub num
exception_stub_\num:
movl $0, error_code
movl $\num, vector
jmp exception_common
.endm
.macro stub_err num
exception_stub_\num:
popl error_code
movl $\num, vector
jmp exception_common
.endm
stub 0
stub 1
stub 2
stub 3
stub 4
stub 5
stub 6
stub 7
stub_err 8
stub 9
stub_err 10
stub_err 11
stub_err 12
stub_err 13
stub_err 14
stub 15
stub 16
stub_err 17
stub 18
stub 19
stub 20
stub 21
stub 22
stub 23
stub 24
stub 25
stub 26
stub 27
stub 28
stub 29
stub_err 30
stub 31
exception_common:
/*
* Save off the stack pointer and old eax value and install the
* exception stack. eax points to the old stack which has the
* exception ip, cs, and flags.
*/
mov %esp, old_esp
addl $12, old_esp
mov %eax, old_eax
mov %esp, %eax
mov exception_stack_end, %esp
/*
* Push values onto the top of the exception stack to form an
* exception state structure.
*/
pushl vector
pushl error_code
pushl %gs
pushl %fs
pushl %es
pushl %ds
pushl %ss
pushl 4(%eax)
pushl 8(%eax)
pushl (%eax)
pushl %edi
pushl %esi
pushl %ebp
pushl old_esp
pushl %ebx
pushl %edx
pushl %ecx
pushl old_eax
/*
* Call the C exception handler. It will find the exception state on
* the exception stack. Not passing parameters means we don't have to
* worry about what ABI is being used.
*/
call exception_handler
/*
* Restore state from the exception state structure, including any
* changes that might have been made.
*/
popl old_eax
popl %ecx
popl %edx
popl %ebx
popl old_esp
mov old_esp, %eax
subl $12, %eax
popl %ebp
popl %esi
popl %edi
popl (%eax)
popl 8(%eax)
popl 4(%eax)
popl %ss
popl %ds
popl %es
popl %fs
popl %gs
mov %eax, %esp
mov old_eax, %eax
/* Return from the exception. */
iretl
/*
* We need segment selectors for the IDT, so we need to know where things are
* in the GDT. We set one up here which is pretty standard and largely copied
* from coreboot.
*/
.align 8
gdt:
/* selgdt 0, unused */
.word 0x0000, 0x0000
.byte 0x00, 0x00, 0x00, 0x00
/* selgdt 8, unused */
.word 0x0000, 0x0000
.byte 0x00, 0x00, 0x00, 0x00
/* selgdt 0x10, flat 4GB code segment */
.word 0xffff, 0x0000
.byte 0x00, 0x9b, 0xcf, 0x00
/* selgdt 0x18, flat 4GB data segment */
.word 0xffff, 0x0000
.byte 0x00, 0x93, 0xcf, 0x00
gdt_end:
/* GDT pointer for use with lgdt */
gdt_ptr:
.word gdt_end - gdt - 1
.long gdt
/*
* Record the target and construct the actual entry at init time. This
* is necessary because the linker doesn't want to construct the entry
* for us.
*/
.macro interrupt_gate target
.long \target
.long \target
.endm
.align 8
.global idt
idt:
interrupt_gate exception_stub_0
interrupt_gate exception_stub_1
interrupt_gate exception_stub_2
interrupt_gate exception_stub_3
interrupt_gate exception_stub_4
interrupt_gate exception_stub_5
interrupt_gate exception_stub_6
interrupt_gate exception_stub_7
interrupt_gate exception_stub_8
interrupt_gate exception_stub_9
interrupt_gate exception_stub_10
interrupt_gate exception_stub_11
interrupt_gate exception_stub_12
interrupt_gate exception_stub_13
interrupt_gate exception_stub_14
interrupt_gate exception_stub_15
interrupt_gate exception_stub_16
interrupt_gate exception_stub_17
interrupt_gate exception_stub_18
interrupt_gate exception_stub_19
interrupt_gate exception_stub_20
interrupt_gate exception_stub_21
interrupt_gate exception_stub_22
interrupt_gate exception_stub_23
interrupt_gate exception_stub_24
interrupt_gate exception_stub_25
interrupt_gate exception_stub_26
interrupt_gate exception_stub_27
interrupt_gate exception_stub_28
interrupt_gate exception_stub_29
interrupt_gate exception_stub_30
interrupt_gate exception_stub_31
idt_end:
/* IDT pointer for use with lidt */
idt_ptr:
.word idt_end - idt - 1
.long idt
.global exception_init_asm
exception_init_asm:
/* Save eax so we can use it as a temporary variable. */
pushl %eax
/* Install the GDT. */
lgdt gdt_ptr
/* Load the segment registers from it. */
ljmp $0x10, $1f
1: movl $0x18, %eax
movl %eax, %ds
movl %eax, %es
movl %eax, %ss
movl %eax, %fs
movl %eax, %gs
/*
* Loop over the entries which start out as two copies of the target
* address. We can turn them into real interrupt gates by selectively
* replacing certain bit fields.
*/
movl $idt, %eax
1:
andl $0x0000ffff, (%eax)
orl $0x00100000, (%eax)
andl $0xffff0000, 4(%eax)
orl $0x0000ee00, 4(%eax)
addl $8, %eax
cmp $idt_end, %eax
jne 1b
/* Install the IDT. */
lidt idt_ptr
/* Restore eax and return to the caller. */
popl %eax
ret

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@ -27,6 +27,7 @@
* SUCH DAMAGE.
*/
#include <exception.h>
#include <libpayload.h>
unsigned long loader_eax; /**< The value of EAX passed from the loader */
@ -54,6 +55,8 @@ void start_main(void)
console_init();
#endif
exception_init();
/*
* Any other system init that has to happen before the
* user gets control goes here.

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@ -30,9 +30,9 @@
#ifndef _ARCH_EXCEPTION_H
#define _ARCH_EXCEPTION_H
#include <exception.h>
#include <stdint.h>
void exception_init(void);
void set_vbar(uint32_t vbar);
#endif

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@ -0,0 +1,37 @@
/*
* This file is part of the libpayload project.
*
* Copyright 2013 Google Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef _EXCEPTION_H
#define _EXCEPTION_H
#include <stdint.h>
void exception_init(void);
#endif