zephyr/arch/sparc/core/fatal.c

219 lines
6.2 KiB
C

/*
* Copyright (c) 2019-2020 Cobham Gaisler AB
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <kernel.h>
#include <logging/log.h>
LOG_MODULE_DECLARE(os, CONFIG_KERNEL_LOG_LEVEL);
/*
* EXAMPLE OUTPUT
*
* ---------------------------------------------------------------------
*
* tt = 0x02, illegal_instruction
*
* INS LOCALS OUTS GLOBALS
* 0: 00000000 f3900fc0 40007c50 00000000
* 1: 00000000 40004bf0 40008d30 40008c00
* 2: 00000000 40004bf4 40008000 00000003
* 3: 40009158 00000000 40009000 00000002
* 4: 40008fa8 40003c00 40008fa8 00000008
* 5: 40009000 f3400fc0 00000000 00000080
* 6: 4000a1f8 40000050 4000a190 00000000
* 7: 40002308 00000000 40001fb8 000000c1
*
* psr: f30000c7 wim: 00000008 tbr: 40000020 y: 00000000
* pc: 4000a1f4 npc: 4000a1f8
*
* pc sp
* #0 4000a1f4 4000a190
* #1 40002308 4000a1f8
* #2 40003b24 4000a258
*
* ---------------------------------------------------------------------
*
*
* INTERPRETATION
*
* INS, LOCALS, OUTS and GLOBALS represent the %i, %l, %o and %g
* registers before the trap was taken.
*
* wim, y, pc and npc are the values before the trap was taken.
* tbr has the tbr.tt field (bits 11..4) filled in by hardware
* representing the current trap type. psr is read immediately
* after the trap was taken so it will have the new CWP and ET=0.
*
* The "#i pc sp" rows is the stack backtrace. All register
* windows are flushed to the stack prior to printing. First row
* is the trapping pc and sp (o6).
*
*
* HOW TO USE
*
* When invesetigating a crashed program, the first things to look
* at is typically the tt, pc and sp (o6). You can lookup the pc
* in the assembly list file or use addr2line. In the listing, the
* register values in the table above can be used. The linker map
* file will give a hint on which stack is active and if it has
* overflowed.
*
* psr bits 11..8 is the processor interrupt (priority) level. 0
* is lowest priority level (all can be taken), and 0xf is the
* highest level where only non-maskable interrupts are taken.
*
* g0 is always zero. g5, g6 are never accessed by the compiler.
* g7 is the TLS pointer if enabled. A SAVE instruction decreases
* the current window pointer (psr bits 4..0) which results in %o
* registers becoming %i registers and a new set of %l registers
* appear. RESTORE does the oppposite.
*/
/*
* The SPARC V8 ABI guarantees that the stack pointer register
* (o6) points to an area organized as "struct savearea" below at
* all times when traps are enabled. This is the register save
* area where register window registers can be flushed to the
* stack.
*
* We flushed registers to this space in the fault trap entry
* handler. Note that the space is allocated by the ABI (compiler)
* for each stack frame.
*
* When printing the registers, we get the "local" and "in"
* registers from the ABI stack save area, while the "out" and
* "global" registares are taken from the exception stack frame
* generated in the fault trap entry.
*/
struct savearea {
uint32_t local[8];
uint32_t in[8];
};
/*
* Exception trap type (tt) values according to The SPARC V8
* manual, Table 7-1.
*/
static const struct {
int tt;
const char *desc;
} TTDESC[] = {
{ .tt = 0x02, .desc = "illegal_instruction", },
{ .tt = 0x07, .desc = "mem_address_not_aligned", },
{ .tt = 0x2B, .desc = "data_store_error", },
{ .tt = 0x29, .desc = "data_access_error", },
{ .tt = 0x09, .desc = "data_access_exception", },
{ .tt = 0x21, .desc = "instruction_access_error", },
{ .tt = 0x01, .desc = "instruction_access_exception", },
{ .tt = 0x04, .desc = "fp_disabled", },
{ .tt = 0x08, .desc = "fp_exception", },
{ .tt = 0x2A, .desc = "division_by_zero", },
{ .tt = 0x03, .desc = "privileged_instruction", },
{ .tt = 0x20, .desc = "r_register_access_error", },
{ .tt = 0x0B, .desc = "watchpoint_detected", },
{ .tt = 0x2C, .desc = "data_access_MMU_miss", },
{ .tt = 0x3C, .desc = "instruction_access_MMU_miss", },
{ .tt = 0x05, .desc = "window_overflow", },
{ .tt = 0x06, .desc = "window_underflow", },
{ .tt = 0x0A, .desc = "tag_overflow", },
};
static void print_trap_type(const z_arch_esf_t *esf)
{
const int tt = (esf->tbr & TBR_TT) >> TBR_TT_BIT;
const char *desc = "unknown";
if (tt & 0x80) {
desc = "trap_instruction";
} else if (tt >= 0x11 && tt <= 0x1F) {
desc = "interrupt";
} else {
for (int i = 0; i < ARRAY_SIZE(TTDESC); i++) {
if (TTDESC[i].tt == tt) {
desc = TTDESC[i].desc;
break;
}
}
}
LOG_ERR("tt = 0x%02X, %s", tt, desc);
}
static void print_integer_registers(const z_arch_esf_t *esf)
{
const struct savearea *flushed = (struct savearea *) esf->out[6];
LOG_ERR(" INS LOCALS OUTS GLOBALS");
for (int i = 0; i < 8; i++) {
LOG_ERR(
" %d: %08x %08x %08x %08x",
i,
flushed ? flushed->in[i] : 0,
flushed ? flushed->local[i] : 0,
esf->out[i],
esf->global[i]
);
}
}
static void print_special_registers(const z_arch_esf_t *esf)
{
LOG_ERR(
"psr: %08x wim: %08x tbr: %08x y: %08x",
esf->psr, esf->wim, esf->tbr, esf->y
);
LOG_ERR(" pc: %08x npc: %08x", esf->pc, esf->npc);
}
static void print_backtrace(const z_arch_esf_t *esf)
{
const int MAX_LOGLINES = 40;
const struct savearea *s = (struct savearea *) esf->out[6];
LOG_ERR(" pc sp");
LOG_ERR(" #0 %08x %08x", esf->pc, (unsigned int) s);
for (int i = 1; s && i < MAX_LOGLINES; i++) {
const uint32_t pc = s->in[7];
const uint32_t sp = s->in[6];
if (sp == 0U && pc == 0U) {
break;
}
LOG_ERR(" #%-2d %08x %08x", i, pc, sp);
if (sp == 0U || sp & 7U) {
break;
}
s = (const struct savearea *) sp;
}
}
static void print_all(const z_arch_esf_t *esf)
{
LOG_ERR("");
print_trap_type(esf);
LOG_ERR("");
print_integer_registers(esf);
LOG_ERR("");
print_special_registers(esf);
LOG_ERR("");
print_backtrace(esf);
LOG_ERR("");
}
FUNC_NORETURN void z_sparc_fatal_error(unsigned int reason,
const z_arch_esf_t *esf)
{
if (esf != NULL) {
if (IS_ENABLED(CONFIG_EXTRA_EXCEPTION_INFO)) {
print_all(esf);
} else {
print_special_registers(esf);
}
}
z_fatal_error(reason, esf);
CODE_UNREACHABLE;
}