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// SPDX-License-Identifier: MPL-2.0
// (c) Hare authors <https://harelang.org>
use debug::image;
use rt;
use unix::signal;
use unix::signal::{sig};
use fmt;
// altstack.s
let altstack: [ALTSTACK_SIZE]uintptr;
// 16 KiB, sync with altstack.s
def ALTSTACK_SIZE: size = 16384;
@init fn init_overflow() void = {
rt::sigaltstack(&rt::stack_t {
ss_sp = &altstack,
ss_flags = 0,
ss_size = ALTSTACK_SIZE,
}, null)!;
signal::handle(sig::SEGV, &signal_handler, signal::flag::ONSTACK);
signal::handle(sig::FPE, &signal_handler, signal::flag::ONSTACK);
signal::handle(sig::BUS, &signal_handler, signal::flag::ONSTACK);
signal::handle(sig::ILL, &signal_handler, signal::flag::ONSTACK);
};
fn signal_handler(sig: sig, info: *signal::siginfo, uctx: *opaque) void = {
begin_fatal();
const ip = uctx_ip(uctx);
const sp = uctx_sp(uctx);
const addr = info.addr: uintptr;
let frame = uctx_frame(uctx);
switch (sig) {
case sig::SEGV =>
const is_overflow = addr & ~0xFFFF == sp & ~0xFFFF;
fmt::errorfln("{} ({}) at address 0x{:x}",
if (is_overflow) "Stack overflow"
else "Illegal pointer access",
errcode_str(sig, info.code), addr): void;
case sig::BUS =>
fmt::errorfln("Bus error ({}) at address 0x{:x}",
errcode_str(sig, info.code), addr): void;
case sig::FPE =>
// addr is the location of the faulting instruction, construct
// an additional synethetic stack frame
let copy = frame; frame = mkframe(©, addr);
fmt::errorfln("Arithmetic exception ({})",
errcode_str(sig, info.code)): void;
case => void;
};
const self = match (image::self()) {
case let img: image::image =>
yield img;
case => halt();
};
defer image::close(&self);
fmt::errorln("Backtrace:"): void;
backtrace(&self, frame);
halt();
};
fn errcode_str(sig: sig, code: signal::code) const str = {
// Note: this only handles a few cases by design
// It also is limited only to error codes defined by POSIX
switch (sig) {
case sig::ILL =>
switch (code) {
case signal::code::ILLOPC => return "illegal opcode";
case signal::code::ILLOPN => return "illegal operand";
case signal::code::ILLADR => return "illegal addressing mode";
case signal::code::ILLTRP => return "illegal trap";
case signal::code::PRVOPC => return "privileged opcode";
case signal::code::PRVREG => return "privileged register";
case signal::code::COPROC => return "coprocessor error";
case signal::code::BADSTK => return "internal stack error";
case => void;
};
case sig::FPE =>
switch (code) {
case signal::code::INTDIV => return "integer divide by zero";
case signal::code::INTOVF => return "integer overflow";
case signal::code::FLTDIV => return "floating-point divide by zero";
case signal::code::FLTOVF => return "floating-point overflow";
case signal::code::FLTUND => return "floating-point underflow";
case signal::code::FLTRES => return "floating-point inexact result";
case signal::code::FLTINV => return "invalid floating-point operation";
case signal::code::FLTSUB => return "subscript out of range";
case => void;
};
case sig::SEGV =>
switch (code) {
case signal::code::MAPERR => return "address not mapped to object";
case signal::code::ACCERR => return "invalid permissions for mapped object";
case => void;
};
case sig::BUS =>
switch (code) {
case signal::code::ADRALN => return "invalid address alignment";
case signal::code::ADRERR => return "nonexistent physical address";
case signal::code::OBJERR => return "object-specific hardware error";
case => void;
};
case => void;
};
return "unknown reason";
};
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