diff options
| -rw-r--r-- | include/backtrace.h | 20 | ||||
| -rw-r--r-- | include/panic.h | 2 | ||||
| -rw-r--r-- | src/arch/amd64/backtrace.c | 53 | ||||
| -rw-r--r-- | src/arch/amd64/boot.S | 7 | ||||
| -rw-r--r-- | src/arch/amd64/idt.S | 13 | ||||
| -rw-r--r-- | src/arch/amd64/idt.c | 5 | ||||
| -rw-r--r-- | src/arch/amd64/panic.c | 15 | ||||
| -rw-r--r-- | src/kmain.c | 24 |
8 files changed, 130 insertions, 9 deletions
diff --git a/include/backtrace.h b/include/backtrace.h new file mode 100644 index 0000000..2abece7 --- /dev/null +++ b/include/backtrace.h @@ -0,0 +1,20 @@ +#pragma once + +#include <stddef.h> + +// Fill dst with a stack trace consisting of return addresses +// in order from top to bottom. returns the number filled (at most len) +size_t backtrace(void **dst, size_t len); + + +// same as backtrace but with specified instruction and base pointer +size_t backtrace_ex(void **dst, size_t len, void* ip, void *bp); + +// TODO symbols +//size_t backtrace_symbols(char *const *dst, size_t len); + +// Log a backtrace +void log_backtrace(); + +// same as log_backtrace with specified insruction and base pointer +void log_backtrace_ex(void *ip, void *bp); diff --git a/include/panic.h b/include/panic.h index 21715fd..4f8592e 100644 --- a/include/panic.h +++ b/include/panic.h @@ -6,3 +6,5 @@ #define panic(msg) _panic_impl(_PANIC_STR(__LINE__), __FILE__, msg) _Noreturn void _panic_impl(char *line, char *file, char *msg); + +_Noreturn void panic_interrupt(void *ip, void *bp, char *msg); diff --git a/src/arch/amd64/backtrace.c b/src/arch/amd64/backtrace.c new file mode 100644 index 0000000..c882fa0 --- /dev/null +++ b/src/arch/amd64/backtrace.c @@ -0,0 +1,53 @@ +#include <backtrace.h> +#include <lib.h> +#include "serial.h" + +struct stackframe { + struct stackframe *rbp; + void *rip; +}; + +size_t backtrace(void **dst, size_t len) { + struct stackframe *rbp; + __asm__ volatile ("mov %%rbp, %0" : "=r"(rbp)); + return backtrace_ex(dst, len, rbp->rip, rbp->rbp); +} + +size_t backtrace_ex(void **dst, size_t len, void *ip, void *bp) { + struct stackframe *frame = bp; + __asm__ volatile ("mov %%rbp, %0" : "=r"(frame)); + if(len > 0) { + dst[0] = ip; + } + size_t i; + for(i = 1; frame && i < len; i++) { + dst[i] = frame->rip; + frame = frame->rbp; + } + return i; +} + +void log_backtrace() { + struct stackframe *rbp; + __asm__ volatile ("mov %%rbp, %0" : "=r"(rbp)); + log_backtrace_ex(rbp->rip, rbp->rbp); +} + + +void log_backtrace_ex(void *ip, void *bp) { + struct stackframe *frame = bp; + char buf[20]; + serial_out_str("Stack trace:\n"); + ultoa((size_t)ip, buf, 16); + serial_out_str(" 0x"); + serial_out_str(buf); + serial_out_str("\n"); + while(frame) { + ultoa((size_t)frame->rip, buf, 16); + serial_out_str(" 0x"); + serial_out_str(buf); + serial_out_str("\n"); + frame = frame->rbp; + } + +} diff --git a/src/arch/amd64/boot.S b/src/arch/amd64/boot.S index c6145d5..6768beb 100644 --- a/src/arch/amd64/boot.S +++ b/src/arch/amd64/boot.S @@ -136,13 +136,16 @@ start: bits 64 code64: - mov dx, 16 - mov ds, dx + mov dx, 16 ; set segment registers + mov ds, dx ; so that interrupts work mov ss, dx + xor rbp, rbp ; set ebp to 0 so we know where to end stack traces + pop rdi call amd64_shim mov rdi, rax + sti call kmain cli diff --git a/src/arch/amd64/idt.S b/src/arch/amd64/idt.S index 32670c8..8cb537e 100644 --- a/src/arch/amd64/idt.S +++ b/src/arch/amd64/idt.S @@ -49,8 +49,10 @@ align 8 isr_stub_%+%1: PUSHALL cld - mov rdi, %1 - mov rsi, 0 + mov rdi, %1 ; exception number + mov rsi, 0 ; placeholder error code + mov rdx, [rsp + 15 * 8] ; instruction pointer + mov rcx, rbp ; base pointer for stack trace call idt_exception_handler POPALL iretq @@ -64,10 +66,13 @@ align 8 isr_stub_%+%1: PUSHALL cld - mov rdi, %1 - pop rsi + mov rdi, %1 ; exception number + mov rsi, [rsp + 15 * 8] ; error code + mov rdx, [rsp + 16 * 8] ; instruction pointer + mov rcx, rbp ; base pointer for stack trace call idt_exception_handler POPALL + sub rsp, 8 ; discard error code iretq %endmacro diff --git a/src/arch/amd64/idt.c b/src/arch/amd64/idt.c index 83b792c..b4a11bb 100644 --- a/src/arch/amd64/idt.c +++ b/src/arch/amd64/idt.c @@ -4,6 +4,7 @@ #include <lib.h> #include <serial.h> +#include "backtrace.h" #include "idt.h" #include "pic.h" @@ -107,7 +108,7 @@ char *EXCEPTIONS[] = { "0x1F Reserved", }; -void idt_exception_handler(uint64_t exception, uint64_t code) { +void idt_exception_handler(uint64_t exception, uint64_t code, void *rip, void *rbp) { // TODO don't just panic char buf[24]; char msg[256] = "Exception "; @@ -127,7 +128,7 @@ void idt_exception_handler(uint64_t exception, uint64_t code) { strcat(msg, buf); } - panic(msg); + panic_interrupt(rip, rbp, msg); } void idt_pic_eoi(uint8_t exception) { diff --git a/src/arch/amd64/panic.c b/src/arch/amd64/panic.c index c034b90..7f54f98 100644 --- a/src/arch/amd64/panic.c +++ b/src/arch/amd64/panic.c @@ -1,4 +1,5 @@ #include <panic.h> +#include <backtrace.h> #include "serial.h" #include "bindings.h" @@ -12,7 +13,19 @@ _Noreturn void _panic_impl(char *line, char *file, char *msg) { serial_out_str(line); serial_out_str(":\n"); serial_out_str(msg); - serial_out('\n'); + serial_out_str("\n\n"); + log_backtrace(); + while (1) { + halt(); + } +} + +_Noreturn void panic_interrupt(void *ip, void *bp, char *msg) { + cli(); + serial_out_str("\n\n!!! PANIC !!!\n"); + serial_out_str(msg); + serial_out_str("\n\n"); + log_backtrace_ex(ip, bp); while (1) { halt(); } diff --git a/src/kmain.c b/src/kmain.c index d5bee56..b55b6a5 100644 --- a/src/kmain.c +++ b/src/kmain.c @@ -4,6 +4,30 @@ #include <fb.h> #include <shim.h> +void print_memory() { + size_t WIDTH = 64; + + for(size_t i = 0;; i += WIDTH) { + char buf[20]; + ultoa(i, buf, 16); + serial_out_str("0x"); + for(size_t k = 0; k < 6 - strlen(buf); k++) { + serial_out('0'); + } + serial_out_str(buf); + serial_out_str(": "); + for(size_t j = 0; j < WIDTH; j++) { + char x = *(char *)(i + j); + if(x < 0x20 || x >= 0x7f) { + serial_out('.'); + } else { + serial_out(x); + } + } + serial_out('\n'); + } +} + void kmain(struct boot_info *info) { memory_init(info->map); serial_out_str("entered kmain\n"); |