Commit a4ebad65 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'x86_sgx_for_6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull x86 SGX updates from Dave Hansen:
 "These fix a deadlock in the SGX NUMA allocator.

  It's probably only triggerable today on servers with buggy BIOSes, but
  it's theoretically possible it can happen on less goofy systems"

* tag 'x86_sgx_for_6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/sgx: Log information when a node lacks an EPC section
  x86/sgx: Fix deadlock in SGX NUMA node search
parents 963d0d60 c8ddc99e

arch/x86/kernel/cpu/sgx/main.c

+21 −13
Original line number Diff line number Diff line
@@ -475,24 +475,25 @@ struct sgx_epc_page *__sgx_alloc_epc_page(void) 
{

	struct sgx_epc_page *page;

	int nid_of_current = numa_node_id();

	int nid = nid_of_current;

	int nid_start, nid;



	if (node_isset(nid_of_current, sgx_numa_mask)) {

		page = __sgx_alloc_epc_page_from_node(nid_of_current);

		if (page)

			return page;

	}



	/* Fall back to the non-local NUMA nodes: */

	while (true) {

		nid = next_node_in(nid, sgx_numa_mask);

		if (nid == nid_of_current)

			break;

	/*

	 * Try local node first. If it doesn't have an EPC section,

	 * fall back to the non-local NUMA nodes.

	 */

	if (node_isset(nid_of_current, sgx_numa_mask))

		nid_start = nid_of_current;

	else

		nid_start = next_node_in(nid_of_current, sgx_numa_mask);



	nid = nid_start;

	do {

		page = __sgx_alloc_epc_page_from_node(nid);

		if (page)

			return page;

	}



		nid = next_node_in(nid, sgx_numa_mask);

	} while (nid != nid_start);



	return ERR_PTR(-ENOMEM);

}
@@ -847,6 +848,13 @@ static bool __init sgx_page_cache_init(void) 
		return false;

	}



	for_each_online_node(nid) {

		if (!node_isset(nid, sgx_numa_mask) &&

		    node_state(nid, N_MEMORY) && node_state(nid, N_CPU))

			pr_info("node%d has both CPUs and memory but doesn't have an EPC section\n",

				nid);

	}



	return true;

}