Re: [PATCH 07/32] mm: Bring back vmalloc_exec

From: Johannes Thumshirn
Date: Wed May 10 2023 - 11:05:59 EST


On 09.05.23 18:56, Kent Overstreet wrote:
> +/**
> + * vmalloc_exec - allocate virtually contiguous, executable memory
> + * @size: allocation size
> + *
> + * Kernel-internal function to allocate enough pages to cover @size
> + * the page level allocator and map them into contiguous and
> + * executable kernel virtual space.
> + *
> + * For tight control over page level allocator and protection flags
> + * use __vmalloc() instead.
> + *
> + * Return: pointer to the allocated memory or %NULL on error
> + */
> +void *vmalloc_exec(unsigned long size, gfp_t gfp_mask)
> +{
> + return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
> + gfp_mask, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS,
> + NUMA_NO_NODE, __builtin_return_address(0));
> +}
> +EXPORT_SYMBOL_GPL(vmalloc_exec);

Uh W+X memory reagions.
The 90s called, they want their shellcode back.