Merge tag 'x86_sgx_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 SGX updates from Borislav Petkov:
 "Add the guest side of SGX support in KVM guests. Work by Sean
  Christopherson, Kai Huang and Jarkko Sakkinen.

  Along with the usual fixes, cleanups and improvements"

* tag 'x86_sgx_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
  x86/sgx: Mark sgx_vepc_vm_ops static
  x86/sgx: Do not update sgx_nr_free_pages in sgx_setup_epc_section()
  x86/sgx: Move provisioning device creation out of SGX driver
  x86/sgx: Add helpers to expose ECREATE and EINIT to KVM
  x86/sgx: Add helper to update SGX_LEPUBKEYHASHn MSRs
  x86/sgx: Add encls_faulted() helper
  x86/sgx: Add SGX2 ENCLS leaf definitions (EAUG, EMODPR and EMODT)
  x86/sgx: Move ENCLS leaf definitions to sgx.h
  x86/sgx: Expose SGX architectural definitions to the kernel
  x86/sgx: Initialize virtual EPC driver even when SGX driver is disabled
  x86/cpu/intel: Allow SGX virtualization without Launch Control support
  x86/sgx: Introduce virtual EPC for use by KVM guests
  x86/sgx: Add SGX_CHILD_PRESENT hardware error code
  x86/sgx: Wipe out EREMOVE from sgx_free_epc_page()
  x86/cpufeatures: Add SGX1 and SGX2 sub-features
  x86/cpufeatures: Make SGX_LC feature bit depend on SGX bit
  x86/sgx: Remove unnecessary kmap() from sgx_ioc_enclave_init()
  selftests/sgx: Use getauxval() to simplify test code
  selftests/sgx: Improve error detection and messages
  x86/sgx: Add a basic NUMA allocation scheme to sgx_alloc_epc_page()
  ...

tools/testing/selftests/sgx/defines.h

@@ -14,7 +14,7 @@
 #define __aligned(x) __attribute__((__aligned__(x)))
 #define __packed __attribute__((packed))
 
-#include "../../../../arch/x86/kernel/cpu/sgx/arch.h"
+#include "../../../../arch/x86/include/asm/sgx.h"
 #include "../../../../arch/x86/include/asm/enclu.h"
 #include "../../../../arch/x86/include/uapi/asm/sgx.h"
 

tools/testing/selftests/sgx/load.c

@@ -45,19 +45,19 @@ static bool encl_map_bin(const char *path, struct encl *encl)
 
 	fd = open(path, O_RDONLY);
 	if (fd == -1)  {
-		perror("open()");
+		perror("enclave executable open()");
 		return false;
 	}
 
 	ret = stat(path, &sb);
 	if (ret) {
-		perror("stat()");
+		perror("enclave executable stat()");
 		goto err;
 	}
 
 	bin = mmap(NULL, sb.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
 	if (bin == MAP_FAILED) {
-		perror("mmap()");
+		perror("enclave executable mmap()");
 		goto err;
 	}
 
@@ -90,8 +90,7 @@ static bool encl_ioc_create(struct encl *encl)
 	ioc.src = (unsigned long)secs;
 	rc = ioctl(encl->fd, SGX_IOC_ENCLAVE_CREATE, &ioc);
 	if (rc) {
-		fprintf(stderr, "SGX_IOC_ENCLAVE_CREATE failed: errno=%d\n",
-			errno);
+		perror("SGX_IOC_ENCLAVE_CREATE failed");
 		munmap((void *)secs->base, encl->encl_size);
 		return false;
 	}
@@ -116,31 +115,72 @@ static bool encl_ioc_add_pages(struct encl *encl, struct encl_segment *seg)
 
 	rc = ioctl(encl->fd, SGX_IOC_ENCLAVE_ADD_PAGES, &ioc);
 	if (rc < 0) {
-		fprintf(stderr, "SGX_IOC_ENCLAVE_ADD_PAGES failed: errno=%d.\n",
-			errno);
+		perror("SGX_IOC_ENCLAVE_ADD_PAGES failed");
 		return false;
 	}
 
 	return true;
 }
 
+
+
 bool encl_load(const char *path, struct encl *encl)
 {
+	const char device_path[] = "/dev/sgx_enclave";
 	Elf64_Phdr *phdr_tbl;
 	off_t src_offset;
 	Elf64_Ehdr *ehdr;
+	struct stat sb;
+	void *ptr;
 	int i, j;
 	int ret;
+	int fd = -1;
 
 	memset(encl, 0, sizeof(*encl));
 
-	ret = open("/dev/sgx_enclave", O_RDWR);
-	if (ret < 0) {
-		fprintf(stderr, "Unable to open /dev/sgx_enclave\n");
+	fd = open(device_path, O_RDWR);
+	if (fd < 0) {
+		perror("Unable to open /dev/sgx_enclave");
 		goto err;
 	}
 
-	encl->fd = ret;
+	ret = stat(device_path, &sb);
+	if (ret) {
+		perror("device file stat()");
+		goto err;
+	}
+
+	/*
+	 * This just checks if the /dev file has these permission
+	 * bits set.  It does not check that the current user is
+	 * the owner or in the owning group.
+	 */
+	if (!(sb.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))) {
+		fprintf(stderr, "no execute permissions on device file %s\n", device_path);
+		goto err;
+	}
+
+	ptr = mmap(NULL, PAGE_SIZE, PROT_READ, MAP_SHARED, fd, 0);
+	if (ptr == (void *)-1) {
+		perror("mmap for read");
+		goto err;
+	}
+	munmap(ptr, PAGE_SIZE);
+
+#define ERR_MSG \
+"mmap() succeeded for PROT_READ, but failed for PROT_EXEC.\n" \
+" Check that current user has execute permissions on %s and \n" \
+" that /dev does not have noexec set: mount | grep \"/dev .*noexec\"\n" \
+" If so, remount it executable: mount -o remount,exec /dev\n\n"
+
+	ptr = mmap(NULL, PAGE_SIZE, PROT_EXEC, MAP_SHARED, fd, 0);
+	if (ptr == (void *)-1) {
+		fprintf(stderr, ERR_MSG, device_path);
+		goto err;
+	}
+	munmap(ptr, PAGE_SIZE);
+
+	encl->fd = fd;
 
 	if (!encl_map_bin(path, encl))
 		goto err;
@@ -217,6 +257,8 @@ bool encl_load(const char *path, struct encl *encl)
 	return true;
 
 err:
+	if (fd != -1)
+		close(fd);
 	encl_delete(encl);
 	return false;
 }
@@ -229,7 +271,7 @@ static bool encl_map_area(struct encl *encl)
 	area = mmap(NULL, encl_size * 2, PROT_NONE,
 		    MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 	if (area == MAP_FAILED) {
-		perror("mmap");
+		perror("reservation mmap()");
 		return false;
 	}
 
@@ -268,8 +310,7 @@ bool encl_build(struct encl *encl)
 	ioc.sigstruct = (uint64_t)&encl->sigstruct;
 	ret = ioctl(encl->fd, SGX_IOC_ENCLAVE_INIT, &ioc);
 	if (ret) {
-		fprintf(stderr, "SGX_IOC_ENCLAVE_INIT failed: errno=%d\n",
-			errno);
+		perror("SGX_IOC_ENCLAVE_INIT failed");
 		return false;
 	}
 

tools/testing/selftests/sgx/main.c

@@ -15,6 +15,7 @@
 #include <sys/stat.h>
 #include <sys/time.h>
 #include <sys/types.h>
+#include <sys/auxv.h>
 #include "defines.h"
 #include "main.h"
 #include "../kselftest.h"
@@ -28,24 +29,6 @@ struct vdso_symtab {
 	Elf64_Word *elf_hashtab;
 };
 
-static void *vdso_get_base_addr(char *envp[])
-{
-	Elf64_auxv_t *auxv;
-	int i;
-
-	for (i = 0; envp[i]; i++)
-		;
-
-	auxv = (Elf64_auxv_t *)&envp[i + 1];
-
-	for (i = 0; auxv[i].a_type != AT_NULL; i++) {
-		if (auxv[i].a_type == AT_SYSINFO_EHDR)
-			return (void *)auxv[i].a_un.a_val;
-	}
-
-	return NULL;
-}
-
 static Elf64_Dyn *vdso_get_dyntab(void *addr)
 {
 	Elf64_Ehdr *ehdr = addr;
@@ -162,7 +145,7 @@ static int user_handler(long rdi, long rsi, long rdx, long ursp, long r8, long r
 	return 0;
 }
 
-int main(int argc, char *argv[], char *envp[])
+int main(int argc, char *argv[])
 {
 	struct sgx_enclave_run run;
 	struct vdso_symtab symtab;
@@ -195,7 +178,7 @@ int main(int argc, char *argv[], char *envp[])
 		addr = mmap((void *)encl.encl_base + seg->offset, seg->size,
 			    seg->prot, MAP_SHARED | MAP_FIXED, encl.fd, 0);
 		if (addr == MAP_FAILED) {
-			fprintf(stderr, "mmap() failed, errno=%d.\n", errno);
+			perror("mmap() segment failed");
 			exit(KSFT_FAIL);
 		}
 	}
@@ -203,7 +186,8 @@ int main(int argc, char *argv[], char *envp[])
 	memset(&run, 0, sizeof(run));
 	run.tcs = encl.encl_base;
 
-	addr = vdso_get_base_addr(envp);
+	/* Get vDSO base address */
+	addr = (void *)getauxval(AT_SYSINFO_EHDR);
 	if (!addr)
 		goto err;