blob: 451f504bc8efc5d3aab73bebd0a66829551636f2 [file] [log] [blame]
#include "libcflat.h"
#include "desc.h"
#include "processor.h"
#include <setjmp.h>
#ifndef __x86_64__
__attribute__((regparm(1)))
#endif
void do_handle_exception(struct ex_regs *regs);
void set_idt_entry(int vec, void *addr, int dpl)
{
idt_entry_t *e = &boot_idt[vec];
memset(e, 0, sizeof *e);
e->offset0 = (unsigned long)addr;
e->selector = read_cs();
e->ist = 0;
e->type = 14;
e->dpl = dpl;
e->p = 1;
e->offset1 = (unsigned long)addr >> 16;
#ifdef __x86_64__
e->offset2 = (unsigned long)addr >> 32;
#endif
}
void set_idt_dpl(int vec, u16 dpl)
{
idt_entry_t *e = &boot_idt[vec];
e->dpl = dpl;
}
void set_idt_sel(int vec, u16 sel)
{
idt_entry_t *e = &boot_idt[vec];
e->selector = sel;
}
struct ex_record {
unsigned long rip;
unsigned long handler;
};
extern struct ex_record exception_table_start, exception_table_end;
static const char* exception_mnemonic(int vector)
{
switch(vector) {
case 0: return "#DE";
case 1: return "#DB";
case 2: return "#NMI";
case 3: return "#BP";
case 4: return "#OF";
case 5: return "#BR";
case 6: return "#UD";
case 7: return "#NM";
case 8: return "#DF";
case 10: return "#TS";
case 11: return "#NP";
case 12: return "#SS";
case 13: return "#GP";
case 14: return "#PF";
case 16: return "#MF";
case 17: return "#AC";
case 18: return "#MC";
case 19: return "#XM";
default: return "#??";
}
}
void unhandled_exception(struct ex_regs *regs, bool cpu)
{
printf("Unhandled %sexception %ld %s at ip %016lx\n",
cpu ? "cpu " : "", regs->vector,
exception_mnemonic(regs->vector), regs->rip);
if (regs->vector == 14)
printf("PF at %#lx addr %#lx\n", regs->rip, read_cr2());
printf("error_code=%04lx rflags=%08lx cs=%08lx\n"
"rax=%016lx rcx=%016lx rdx=%016lx rbx=%016lx\n"
"rbp=%016lx rsi=%016lx rdi=%016lx\n"
#ifdef __x86_64__
" r8=%016lx r9=%016lx r10=%016lx r11=%016lx\n"
"r12=%016lx r13=%016lx r14=%016lx r15=%016lx\n"
#endif
"cr0=%016lx cr2=%016lx cr3=%016lx cr4=%016lx\n"
#ifdef __x86_64__
"cr8=%016lx\n"
#endif
,
regs->error_code, regs->rflags, regs->cs,
regs->rax, regs->rcx, regs->rdx, regs->rbx,
regs->rbp, regs->rsi, regs->rdi,
#ifdef __x86_64__
regs->r8, regs->r9, regs->r10, regs->r11,
regs->r12, regs->r13, regs->r14, regs->r15,
#endif
read_cr0(), read_cr2(), read_cr3(), read_cr4()
#ifdef __x86_64__
, read_cr8()
#endif
);
dump_frame_stack((void*) regs->rip, (void*) regs->rbp);
abort();
}
static void check_exception_table(struct ex_regs *regs)
{
struct ex_record *ex;
unsigned ex_val;
ex_val = regs->vector | (regs->error_code << 16) |
(((regs->rflags >> 16) & 1) << 8);
asm("mov %0, %%gs:4" : : "r"(ex_val));
for (ex = &exception_table_start; ex != &exception_table_end; ++ex) {
if (ex->rip == regs->rip) {
regs->rip = ex->handler;
return;
}
}
unhandled_exception(regs, false);
}
static handler exception_handlers[32];
handler handle_exception(u8 v, handler fn)
{
handler old;
old = exception_handlers[v];
if (v < 32)
exception_handlers[v] = fn;
return old;
}
#ifndef __x86_64__
__attribute__((regparm(1)))
#endif
void do_handle_exception(struct ex_regs *regs)
{
if (regs->vector < 32 && exception_handlers[regs->vector]) {
exception_handlers[regs->vector](regs);
return;
}
unhandled_exception(regs, true);
}
#define EX(NAME, N) extern char NAME##_fault; \
asm (".pushsection .text \n\t" \
#NAME"_fault: \n\t" \
"push"W" $0 \n\t" \
"push"W" $"#N" \n\t" \
"jmp __handle_exception \n\t" \
".popsection")
#define EX_E(NAME, N) extern char NAME##_fault; \
asm (".pushsection .text \n\t" \
#NAME"_fault: \n\t" \
"push"W" $"#N" \n\t" \
"jmp __handle_exception \n\t" \
".popsection")
EX(de, 0);
EX(db, 1);
EX(nmi, 2);
EX(bp, 3);
EX(of, 4);
EX(br, 5);
EX(ud, 6);
EX(nm, 7);
EX_E(df, 8);
EX_E(ts, 10);
EX_E(np, 11);
EX_E(ss, 12);
EX_E(gp, 13);
EX_E(pf, 14);
EX(mf, 16);
EX_E(ac, 17);
EX(mc, 18);
EX(xm, 19);
asm (".pushsection .text \n\t"
"__handle_exception: \n\t"
#ifdef __x86_64__
"push %r15; push %r14; push %r13; push %r12 \n\t"
"push %r11; push %r10; push %r9; push %r8 \n\t"
#endif
"push %"R "di; push %"R "si; push %"R "bp; sub $"S", %"R "sp \n\t"
"push %"R "bx; push %"R "dx; push %"R "cx; push %"R "ax \n\t"
#ifdef __x86_64__
"mov %"R "sp, %"R "di \n\t"
#else
"mov %"R "sp, %"R "ax \n\t"
#endif
"call do_handle_exception \n\t"
"pop %"R "ax; pop %"R "cx; pop %"R "dx; pop %"R "bx \n\t"
"add $"S", %"R "sp; pop %"R "bp; pop %"R "si; pop %"R "di \n\t"
#ifdef __x86_64__
"pop %r8; pop %r9; pop %r10; pop %r11 \n\t"
"pop %r12; pop %r13; pop %r14; pop %r15 \n\t"
#endif
"add $"S", %"R "sp \n\t"
"add $"S", %"R "sp \n\t"
"iret"W" \n\t"
".popsection");
static void *idt_handlers[32] = {
[0] = &de_fault,
[1] = &db_fault,
[2] = &nmi_fault,
[3] = &bp_fault,
[4] = &of_fault,
[5] = &br_fault,
[6] = &ud_fault,
[7] = &nm_fault,
[8] = &df_fault,
[10] = &ts_fault,
[11] = &np_fault,
[12] = &ss_fault,
[13] = &gp_fault,
[14] = &pf_fault,
[16] = &mf_fault,
[17] = &ac_fault,
[18] = &mc_fault,
[19] = &xm_fault,
};
void setup_idt(void)
{
int i;
static bool idt_initialized = false;
if (idt_initialized) {
return;
}
idt_initialized = true;
for (i = 0; i < 32; i++)
if (idt_handlers[i])
set_idt_entry(i, idt_handlers[i], 0);
handle_exception(0, check_exception_table);
handle_exception(6, check_exception_table);
handle_exception(13, check_exception_table);
}
unsigned exception_vector(void)
{
unsigned char vector;
asm("movb %%gs:4, %0" : "=q"(vector));
return vector;
}
int write_cr4_checking(unsigned long val)
{
asm volatile(ASM_TRY("1f")
"mov %0,%%cr4\n\t"
"1:": : "r" (val));
return exception_vector();
}
unsigned exception_error_code(void)
{
unsigned short error_code;
asm("mov %%gs:6, %0" : "=r"(error_code));
return error_code;
}
bool exception_rflags_rf(void)
{
unsigned char rf_flag;
asm("movb %%gs:5, %b0" : "=q"(rf_flag));
return rf_flag & 1;
}
static char intr_alt_stack[4096];
#ifndef __x86_64__
void set_gdt_entry(int sel, u32 base, u32 limit, u8 access, u8 gran)
{
int num = sel >> 3;
/* Setup the descriptor base address */
gdt32[num].base_low = (base & 0xFFFF);
gdt32[num].base_middle = (base >> 16) & 0xFF;
gdt32[num].base_high = (base >> 24) & 0xFF;
/* Setup the descriptor limits */
gdt32[num].limit_low = (limit & 0xFFFF);
gdt32[num].granularity = ((limit >> 16) & 0x0F);
/* Finally, set up the granularity and access flags */
gdt32[num].granularity |= (gran & 0xF0);
gdt32[num].access = access;
}
void set_gdt_task_gate(u16 sel, u16 tss_sel)
{
set_gdt_entry(sel, tss_sel, 0, 0x85, 0); // task, present
}
void set_idt_task_gate(int vec, u16 sel)
{
idt_entry_t *e = &boot_idt[vec];
memset(e, 0, sizeof *e);
e->selector = sel;
e->ist = 0;
e->type = 5;
e->dpl = 0;
e->p = 1;
}
/*
* 0 - main task
* 1 - interrupt task
*/
tss32_t tss_intr;
void setup_tss32(void)
{
u16 desc_size = sizeof(tss32_t);
tss.cr3 = read_cr3();
tss_intr.cr3 = read_cr3();
tss_intr.ss0 = tss_intr.ss1 = tss_intr.ss2 = 0x10;
tss_intr.esp = tss_intr.esp0 = tss_intr.esp1 = tss_intr.esp2 =
(u32)intr_alt_stack + 4096;
tss_intr.cs = 0x08;
tss_intr.ds = tss_intr.es = tss_intr.fs = tss_intr.gs = tss_intr.ss = 0x10;
tss_intr.iomap_base = (u16)desc_size;
set_gdt_entry(TSS_INTR, (u32)&tss_intr, desc_size - 1, 0x89, 0x0f);
}
void set_intr_task_gate(int e, void *fn)
{
tss_intr.eip = (u32)fn;
set_idt_task_gate(e, TSS_INTR);
}
void setup_alt_stack(void)
{
setup_tss32();
}
void set_intr_alt_stack(int e, void *fn)
{
set_intr_task_gate(e, fn);
}
void print_current_tss_info(void)
{
u16 tr = str();
if (tr != TSS_MAIN && tr != TSS_INTR)
printf("Unknown TSS %x\n", tr);
else
printf("TR=%x (%s) Main TSS back link %x. Intr TSS back link %x\n",
tr, tr ? "interrupt" : "main", tss.prev, tss_intr.prev);
}
#else
void set_intr_alt_stack(int e, void *addr)
{
set_idt_entry(e, addr, 0);
boot_idt[e].ist = 1;
}
void setup_alt_stack(void)
{
tss.ist1 = (u64)intr_alt_stack + 4096;
}
#endif
static bool exception;
static jmp_buf *exception_jmpbuf;
static void exception_handler_longjmp(void)
{
longjmp(*exception_jmpbuf, 1);
}
static void exception_handler(struct ex_regs *regs)
{
/* longjmp must happen after iret, so do not do it now. */
exception = true;
regs->rip = (unsigned long)&exception_handler_longjmp;
regs->cs = read_cs();
}
bool test_for_exception(unsigned int ex, void (*trigger_func)(void *data),
void *data)
{
handler old;
jmp_buf jmpbuf;
int ret;
old = handle_exception(ex, exception_handler);
ret = set_exception_jmpbuf(jmpbuf);
if (ret == 0)
trigger_func(data);
handle_exception(ex, old);
return ret;
}
void __set_exception_jmpbuf(jmp_buf *addr)
{
exception_jmpbuf = addr;
}