diff --git a/library/std/src/panicking.rs b/library/std/src/panicking.rs index 336e34d7b95..1c972d38100 100644 --- a/library/std/src/panicking.rs +++ b/library/std/src/panicking.rs @@ -23,8 +23,8 @@ use crate::panic::{BacktraceStyle, PanicHookInfo}; use crate::sync::atomic::{AtomicBool, Ordering}; use crate::sync::{PoisonError, RwLock}; +use crate::sys::backtrace; use crate::sys::stdio::panic_output; -use crate::sys::{backtrace, dbg}; use crate::{fmt, intrinsics, process, thread}; // Binary interface to the panic runtime that the standard library depends on. @@ -859,14 +859,6 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { #[cfg_attr(not(test), rustc_std_internal_symbol)] #[cfg(not(feature = "panic_immediate_abort"))] fn rust_panic(msg: &mut dyn PanicPayload) -> ! { - // Break into the debugger if it is attached. - // The return value is not currently used. - // - // This function isn't used anywhere else, and - // using inside `#[panic_handler]` doesn't seem - // to count, so a warning is issued. - let _ = dbg::breakpoint_if_debugging(); - let code = unsafe { __rust_start_panic(msg) }; rtabort!("failed to initiate panic, error {code}") } @@ -874,14 +866,6 @@ fn rust_panic(msg: &mut dyn PanicPayload) -> ! { #[cfg_attr(not(test), rustc_std_internal_symbol)] #[cfg(feature = "panic_immediate_abort")] fn rust_panic(_: &mut dyn PanicPayload) -> ! { - // Break into the debugger if it is attached. - // The return value is not currently used. - // - // This function isn't used anywhere else, and - // using inside `#[panic_handler]` doesn't seem - // to count, so a warning is issued. - let _ = dbg::breakpoint_if_debugging(); - unsafe { crate::intrinsics::abort(); } diff --git a/library/std/src/sys/dbg.rs b/library/std/src/sys/dbg.rs deleted file mode 100644 index 7266a739e78..00000000000 --- a/library/std/src/sys/dbg.rs +++ /dev/null @@ -1,152 +0,0 @@ -//! Debugging aids. - -/// Presence of a debugger. The debugger being concerned -/// is expected to use the OS API to debug this process. -#[derive(Copy, Clone, Debug)] -#[allow(unused)] -pub(crate) enum DebuggerPresence { - /// The debugger is attached to this process. - Detected, - /// The debugger is not attached to this process. - NotDetected, -} - -#[cfg(target_os = "windows")] -mod os { - use super::DebuggerPresence; - - #[link(name = "kernel32")] - extern "system" { - fn IsDebuggerPresent() -> i32; - } - - pub(super) fn is_debugger_present() -> Option { - // SAFETY: No state is shared between threads. The call reads - // a field from the Thread Environment Block using the OS API - // as required by the documentation. - if unsafe { IsDebuggerPresent() } != 0 { - Some(DebuggerPresence::Detected) - } else { - Some(DebuggerPresence::NotDetected) - } - } -} - -#[cfg(any(target_vendor = "apple", target_os = "freebsd"))] -mod os { - use libc::{CTL_KERN, KERN_PROC, KERN_PROC_PID, c_int, sysctl}; - - use super::DebuggerPresence; - use crate::io::{Cursor, Read, Seek, SeekFrom}; - use crate::process; - - const P_TRACED: i32 = 0x00000800; - - // The assumption is that the kernel structures available to the - // user space may not shrink or repurpose the existing fields over - // time. The kernels normally adhere to that for the backward - // compatibility of the user space. - - // The macOS 14.5 SDK comes with a header `MacOSX14.5.sdk/usr/include/sys/sysctl.h` - // that defines `struct kinfo_proc` be of `648` bytes on the 64-bit system. That has - // not changed since macOS 10.13 (released in 2017) at least, validated by building - // a C program in XCode while changing the build target. Apple provides this example - // for reference: https://developer.apple.com/library/archive/qa/qa1361/_index.html. - #[cfg(target_vendor = "apple")] - const KINFO_PROC_SIZE: usize = if cfg!(target_pointer_width = "64") { 648 } else { 492 }; - #[cfg(target_vendor = "apple")] - const KINFO_PROC_FLAGS_OFFSET: u64 = if cfg!(target_pointer_width = "64") { 32 } else { 16 }; - - // Works for FreeBSD stable (13.3, 13.4) and current (14.0, 14.1). - // The size of the structure has stayed the same for a long time, - // at least since 2005: - // https://lists.freebsd.org/pipermail/freebsd-stable/2005-November/019899.html - #[cfg(target_os = "freebsd")] - const KINFO_PROC_SIZE: usize = if cfg!(target_pointer_width = "64") { 1088 } else { 768 }; - #[cfg(target_os = "freebsd")] - const KINFO_PROC_FLAGS_OFFSET: u64 = if cfg!(target_pointer_width = "64") { 368 } else { 296 }; - - pub(super) fn is_debugger_present() -> Option { - debug_assert_ne!(KINFO_PROC_SIZE, 0); - - let mut flags = [0u8; 4]; // `ki_flag` under FreeBSD and `p_flag` under macOS. - let mut mib = [CTL_KERN, KERN_PROC, KERN_PROC_PID, process::id() as c_int]; - let mut info_size = KINFO_PROC_SIZE; - let mut kinfo_proc = [0u8; KINFO_PROC_SIZE]; - - // SAFETY: No state is shared with other threads. The sysctl call - // is safe according to the documentation. - if unsafe { - sysctl( - mib.as_mut_ptr(), - mib.len() as u32, - kinfo_proc.as_mut_ptr().cast(), - &mut info_size, - core::ptr::null_mut(), - 0, - ) - } != 0 - { - return None; - } - debug_assert_eq!(info_size, KINFO_PROC_SIZE); - - let mut reader = Cursor::new(kinfo_proc); - reader.seek(SeekFrom::Start(KINFO_PROC_FLAGS_OFFSET)).ok()?; - reader.read_exact(&mut flags).ok()?; - // Just in case, not limiting this to the little-endian systems. - let flags = i32::from_ne_bytes(flags); - - if flags & P_TRACED != 0 { - Some(DebuggerPresence::Detected) - } else { - Some(DebuggerPresence::NotDetected) - } - } -} - -#[cfg(not(any(target_os = "windows", target_vendor = "apple", target_os = "freebsd")))] -mod os { - pub(super) fn is_debugger_present() -> Option { - None - } -} - -/// Detect the debugger presence. -/// -/// The code does not try to detect the debugger at all costs (e.g., when anti-debugger -/// tricks are at play), it relies on the interfaces provided by the OS. -/// -/// Return value: -/// * `None`: it's not possible to conclude whether the debugger is attached to this -/// process or not. When checking for the presence of the debugger, the detection logic -/// encountered an issue, such as the OS API throwing an error or the feature not being -/// implemented. -/// * `Some(DebuggerPresence::Detected)`: yes, the debugger is attached -/// to this process. -/// * `Some(DebuggerPresence::NotDetected)`: no, the debugger is not -/// attached to this process. -pub(crate) fn is_debugger_present() -> Option { - if cfg!(miri) { None } else { os::is_debugger_present() } -} - -/// Execute the breakpoint instruction if the debugger presence is detected. -/// Useful for breaking into the debugger without the need to set a breakpoint -/// in the debugger. -/// -/// Note that there is a race between attaching or detaching the debugger, and running the -/// breakpoint instruction. This is nonetheless memory-safe, like [`crate::process::abort`] -/// is. In case the debugger is attached and the function is about -/// to run the breakpoint instruction yet right before that the debugger detaches, the -/// process will crash due to running the breakpoint instruction and the debugger not -/// handling the trap exception. -pub(crate) fn breakpoint_if_debugging() -> Option { - let debugger_present = is_debugger_present(); - if let Some(DebuggerPresence::Detected) = debugger_present { - // SAFETY: Executing the breakpoint instruction. No state is shared - // or modified by this code. - unsafe { core::intrinsics::breakpoint() }; - } - - debugger_present -} diff --git a/library/std/src/sys/mod.rs b/library/std/src/sys/mod.rs index df25b84fbbe..f17dd47dece 100644 --- a/library/std/src/sys/mod.rs +++ b/library/std/src/sys/mod.rs @@ -11,7 +11,6 @@ pub mod anonymous_pipe; pub mod backtrace; pub mod cmath; -pub mod dbg; pub mod exit_guard; pub mod os_str; pub mod path;