From ed809e9b79f70719fa9807d363230e576912606b Mon Sep 17 00:00:00 2001 From: Jubilee Young Date: Tue, 23 Jul 2024 01:12:29 -0700 Subject: [PATCH 1/2] std: Unsafe-wrap alloc code held in-common --- library/std/src/sys/pal/common/alloc.rs | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/library/std/src/sys/pal/common/alloc.rs b/library/std/src/sys/pal/common/alloc.rs index 598b6db71f5de..54506c3229675 100644 --- a/library/std/src/sys/pal/common/alloc.rs +++ b/library/std/src/sys/pal/common/alloc.rs @@ -1,3 +1,4 @@ +#![forbid(unsafe_op_in_unsafe_fn)] use crate::alloc::{GlobalAlloc, Layout, System}; use crate::cmp; use crate::ptr; @@ -46,14 +47,16 @@ pub unsafe fn realloc_fallback( old_layout: Layout, new_size: usize, ) -> *mut u8 { - // Docs for GlobalAlloc::realloc require this to be valid: - let new_layout = Layout::from_size_align_unchecked(new_size, old_layout.align()); + // SAFETY: Docs for GlobalAlloc::realloc require this to be valid + unsafe { + let new_layout = Layout::from_size_align_unchecked(new_size, old_layout.align()); - let new_ptr = GlobalAlloc::alloc(alloc, new_layout); - if !new_ptr.is_null() { - let size = cmp::min(old_layout.size(), new_size); - ptr::copy_nonoverlapping(ptr, new_ptr, size); - GlobalAlloc::dealloc(alloc, ptr, old_layout); + let new_ptr = GlobalAlloc::alloc(alloc, new_layout); + if !new_ptr.is_null() { + let size = cmp::min(old_layout.size(), new_size); + ptr::copy_nonoverlapping(ptr, new_ptr, size); + GlobalAlloc::dealloc(alloc, ptr, old_layout); + } + new_ptr } - new_ptr } From e4d89bc802bb26fd489aa63733633c7c034830f1 Mon Sep 17 00:00:00 2001 From: Jubilee Young Date: Tue, 23 Jul 2024 01:16:46 -0700 Subject: [PATCH 2/2] std: Unsafe-wrap backtrace code held in-common --- library/std/src/sys/backtrace.rs | 118 ++++++++++++++++--------------- 1 file changed, 61 insertions(+), 57 deletions(-) diff --git a/library/std/src/sys/backtrace.rs b/library/std/src/sys/backtrace.rs index 7401d8ce32087..133ea520e30c7 100644 --- a/library/std/src/sys/backtrace.rs +++ b/library/std/src/sys/backtrace.rs @@ -1,4 +1,5 @@ //! Common code for printing backtraces. +#![forbid(unsafe_op_in_unsafe_fn)] use crate::backtrace_rs::{self, BacktraceFmt, BytesOrWideString, PrintFmt}; use crate::borrow::Cow; @@ -62,73 +63,76 @@ unsafe fn _print_fmt(fmt: &mut fmt::Formatter<'_>, print_fmt: PrintFmt) -> fmt:: // Start immediately if we're not using a short backtrace. let mut start = print_fmt != PrintFmt::Short; set_image_base(); - backtrace_rs::trace_unsynchronized(|frame| { - if print_fmt == PrintFmt::Short && idx > MAX_NB_FRAMES { - return false; - } + // SAFETY: we roll our own locking in this town + unsafe { + backtrace_rs::trace_unsynchronized(|frame| { + if print_fmt == PrintFmt::Short && idx > MAX_NB_FRAMES { + return false; + } - let mut hit = false; - backtrace_rs::resolve_frame_unsynchronized(frame, |symbol| { - hit = true; - - // Any frames between `__rust_begin_short_backtrace` and `__rust_end_short_backtrace` - // are omitted from the backtrace in short mode, `__rust_end_short_backtrace` will be - // called before the panic hook, so we won't ignore any frames if there is no - // invoke of `__rust_begin_short_backtrace`. - if print_fmt == PrintFmt::Short { - if let Some(sym) = symbol.name().and_then(|s| s.as_str()) { - if start && sym.contains("__rust_begin_short_backtrace") { - start = false; - return; - } - if sym.contains("__rust_end_short_backtrace") { - start = true; - return; - } - if !start { - omitted_count += 1; + let mut hit = false; + backtrace_rs::resolve_frame_unsynchronized(frame, |symbol| { + hit = true; + + // Any frames between `__rust_begin_short_backtrace` and `__rust_end_short_backtrace` + // are omitted from the backtrace in short mode, `__rust_end_short_backtrace` will be + // called before the panic hook, so we won't ignore any frames if there is no + // invoke of `__rust_begin_short_backtrace`. + if print_fmt == PrintFmt::Short { + if let Some(sym) = symbol.name().and_then(|s| s.as_str()) { + if start && sym.contains("__rust_begin_short_backtrace") { + start = false; + return; + } + if sym.contains("__rust_end_short_backtrace") { + start = true; + return; + } + if !start { + omitted_count += 1; + } } } - } - if start { - if omitted_count > 0 { - debug_assert!(print_fmt == PrintFmt::Short); - // only print the message between the middle of frames - if !first_omit { - let _ = writeln!( - bt_fmt.formatter(), - " [... omitted {} frame{} ...]", - omitted_count, - if omitted_count > 1 { "s" } else { "" } - ); + if start { + if omitted_count > 0 { + debug_assert!(print_fmt == PrintFmt::Short); + // only print the message between the middle of frames + if !first_omit { + let _ = writeln!( + bt_fmt.formatter(), + " [... omitted {} frame{} ...]", + omitted_count, + if omitted_count > 1 { "s" } else { "" } + ); + } + first_omit = false; + omitted_count = 0; } - first_omit = false; - omitted_count = 0; + res = bt_fmt.frame().symbol(frame, symbol); } - res = bt_fmt.frame().symbol(frame, symbol); + }); + #[cfg(target_os = "nto")] + if libc::__my_thread_exit as *mut libc::c_void == frame.ip() { + if !hit && start { + use crate::backtrace_rs::SymbolName; + res = bt_fmt.frame().print_raw( + frame.ip(), + Some(SymbolName::new("__my_thread_exit".as_bytes())), + None, + None, + ); + } + return false; } - }); - #[cfg(target_os = "nto")] - if libc::__my_thread_exit as *mut libc::c_void == frame.ip() { if !hit && start { - use crate::backtrace_rs::SymbolName; - res = bt_fmt.frame().print_raw( - frame.ip(), - Some(SymbolName::new("__my_thread_exit".as_bytes())), - None, - None, - ); + res = bt_fmt.frame().print_raw(frame.ip(), None, None, None); } - return false; - } - if !hit && start { - res = bt_fmt.frame().print_raw(frame.ip(), None, None, None); - } - idx += 1; - res.is_ok() - }); + idx += 1; + res.is_ok() + }) + }; res?; bt_fmt.finish()?; if print_fmt == PrintFmt::Short {