Revision f2d7b53c0153f2daa8bc8f1ff29b5a1e03a36458 authored by Alexander Potapenko on 02 November 2022, 10:15:00 UTC, committed by Alexander Potapenko on 02 November 2022, 10:55:06 UTC
There is a case in exc_invalid_op handler that is executed outside the irqentry_enter()/irqentry_exit() region when an UD2 instruction is used to encode a call to __warn(). In that case the `struct pt_regs` passed to the interrupt handler is never unpoisoned by KMSAN (this is normally done in irqentry_enter()), which leads to false positives inside handle_bug(). Use kmsan_unpoison_entry_regs() to explicitly unpoison those registers before using them. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86@kernel.org Signed-off-by: Alexander Potapenko <glider@google.com>
1 parent 4dbc4d5
allocator.rs
// SPDX-License-Identifier: GPL-2.0
//! Allocator support.
use core::alloc::{GlobalAlloc, Layout};
use core::ptr;
use crate::bindings;
struct KernelAllocator;
unsafe impl GlobalAlloc for KernelAllocator {
unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
// `krealloc()` is used instead of `kmalloc()` because the latter is
// an inline function and cannot be bound to as a result.
unsafe { bindings::krealloc(ptr::null(), layout.size(), bindings::GFP_KERNEL) as *mut u8 }
}
unsafe fn dealloc(&self, ptr: *mut u8, _layout: Layout) {
unsafe {
bindings::kfree(ptr as *const core::ffi::c_void);
}
}
}
#[global_allocator]
static ALLOCATOR: KernelAllocator = KernelAllocator;
// `rustc` only generates these for some crate types. Even then, we would need
// to extract the object file that has them from the archive. For the moment,
// let's generate them ourselves instead.
//
// Note that `#[no_mangle]` implies exported too, nowadays.
#[no_mangle]
fn __rust_alloc(size: usize, _align: usize) -> *mut u8 {
unsafe { bindings::krealloc(core::ptr::null(), size, bindings::GFP_KERNEL) as *mut u8 }
}
#[no_mangle]
fn __rust_dealloc(ptr: *mut u8, _size: usize, _align: usize) {
unsafe { bindings::kfree(ptr as *const core::ffi::c_void) };
}
#[no_mangle]
fn __rust_realloc(ptr: *mut u8, _old_size: usize, _align: usize, new_size: usize) -> *mut u8 {
unsafe {
bindings::krealloc(
ptr as *const core::ffi::c_void,
new_size,
bindings::GFP_KERNEL,
) as *mut u8
}
}
#[no_mangle]
fn __rust_alloc_zeroed(size: usize, _align: usize) -> *mut u8 {
unsafe {
bindings::krealloc(
core::ptr::null(),
size,
bindings::GFP_KERNEL | bindings::__GFP_ZERO,
) as *mut u8
}
}
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