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authorLinus Torvalds <torvalds@linux-foundation.org>2024-01-19 00:23:53 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2024-01-19 00:23:53 +0300
commitba7dd8570dc8ad4daa3d1c49a137a7b8479eae07 (patch)
treea363cd5d24cf2420c172d53f932de93ed9c97a8e /tools
parentb0d326da462e20285236e11e4cbc32085de9f363 (diff)
parent981cf568a8644161c2f15c02278ebc2834b51ba6 (diff)
downloadlinux-ba7dd8570dc8ad4daa3d1c49a137a7b8479eae07.tar.xz
Merge tag 'x86_sgx_for_6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 SGX updates from Dave Hansen: "This time, these are entirely confined to SGX selftests fixes. The mini SGX enclave built by the selftests has garnered some attention because it stands alone and does not need the sizable infrastructure of the official SGX SDK. I think that's why folks are suddently interested in cleaning it up. - Clean up selftest compilation issues, mostly from non-gcc compilers - Avoid building selftests when not on x86" * tag 'x86_sgx_for_6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: selftests/sgx: Skip non X86_64 platform selftests/sgx: Remove incomplete ABI sanitization code in test enclave selftests/sgx: Discard unsupported ELF sections selftests/sgx: Ensure expected location of test enclave buffer selftests/sgx: Ensure test enclave buffer is entirely preserved selftests/sgx: Fix linker script asserts selftests/sgx: Handle relocations in test enclave selftests/sgx: Produce static-pie executable for test enclave selftests/sgx: Remove redundant enclave base address save/restore selftests/sgx: Specify freestanding environment for enclave compilation selftests/sgx: Separate linker options selftests/sgx: Include memory clobber for inline asm in test enclave selftests/sgx: Fix uninitialized pointer dereferences in encl_get_entry selftests/sgx: Fix uninitialized pointer dereference in error path
Diffstat (limited to 'tools')
-rw-r--r--tools/testing/selftests/sgx/Makefile14
-rw-r--r--tools/testing/selftests/sgx/defines.h2
-rw-r--r--tools/testing/selftests/sgx/load.c9
-rw-r--r--tools/testing/selftests/sgx/sigstruct.c5
-rw-r--r--tools/testing/selftests/sgx/test_encl.c67
-rw-r--r--tools/testing/selftests/sgx/test_encl.lds10
-rw-r--r--tools/testing/selftests/sgx/test_encl_bootstrap.S28
7 files changed, 78 insertions, 57 deletions
diff --git a/tools/testing/selftests/sgx/Makefile b/tools/testing/selftests/sgx/Makefile
index 50aab6b57da3..867f88ce2570 100644
--- a/tools/testing/selftests/sgx/Makefile
+++ b/tools/testing/selftests/sgx/Makefile
@@ -12,14 +12,16 @@ OBJCOPY := $(CROSS_COMPILE)objcopy
endif
INCLUDES := -I$(top_srcdir)/tools/include
-HOST_CFLAGS := -Wall -Werror -g $(INCLUDES) -fPIC -z noexecstack
-ENCL_CFLAGS := -Wall -Werror -static -nostdlib -nostartfiles -fPIC \
+HOST_CFLAGS := -Wall -Werror -g $(INCLUDES) -fPIC
+HOST_LDFLAGS := -z noexecstack -lcrypto
+ENCL_CFLAGS += -Wall -Werror -static-pie -nostdlib -ffreestanding -fPIE \
-fno-stack-protector -mrdrnd $(INCLUDES)
+ENCL_LDFLAGS := -Wl,-T,test_encl.lds,--build-id=none
+ifeq ($(CAN_BUILD_X86_64), 1)
TEST_CUSTOM_PROGS := $(OUTPUT)/test_sgx
TEST_FILES := $(OUTPUT)/test_encl.elf
-ifeq ($(CAN_BUILD_X86_64), 1)
all: $(TEST_CUSTOM_PROGS) $(OUTPUT)/test_encl.elf
endif
@@ -28,7 +30,7 @@ $(OUTPUT)/test_sgx: $(OUTPUT)/main.o \
$(OUTPUT)/sigstruct.o \
$(OUTPUT)/call.o \
$(OUTPUT)/sign_key.o
- $(CC) $(HOST_CFLAGS) -o $@ $^ -lcrypto
+ $(CC) $(HOST_CFLAGS) -o $@ $^ $(HOST_LDFLAGS)
$(OUTPUT)/main.o: main.c
$(CC) $(HOST_CFLAGS) -c $< -o $@
@@ -45,8 +47,8 @@ $(OUTPUT)/call.o: call.S
$(OUTPUT)/sign_key.o: sign_key.S
$(CC) $(HOST_CFLAGS) -c $< -o $@
-$(OUTPUT)/test_encl.elf: test_encl.lds test_encl.c test_encl_bootstrap.S
- $(CC) $(ENCL_CFLAGS) -T $^ -o $@ -Wl,--build-id=none
+$(OUTPUT)/test_encl.elf: test_encl.c test_encl_bootstrap.S
+ $(CC) $(ENCL_CFLAGS) $^ -o $@ $(ENCL_LDFLAGS)
EXTRA_CLEAN := \
$(OUTPUT)/test_encl.elf \
diff --git a/tools/testing/selftests/sgx/defines.h b/tools/testing/selftests/sgx/defines.h
index d8587c971941..402f8787a71c 100644
--- a/tools/testing/selftests/sgx/defines.h
+++ b/tools/testing/selftests/sgx/defines.h
@@ -13,6 +13,8 @@
#define __aligned(x) __attribute__((__aligned__(x)))
#define __packed __attribute__((packed))
+#define __used __attribute__((used))
+#define __section(x)__attribute__((__section__(x)))
#include "../../../../arch/x86/include/asm/sgx.h"
#include "../../../../arch/x86/include/asm/enclu.h"
diff --git a/tools/testing/selftests/sgx/load.c b/tools/testing/selftests/sgx/load.c
index 94bdeac1cf04..c9f658e44de6 100644
--- a/tools/testing/selftests/sgx/load.c
+++ b/tools/testing/selftests/sgx/load.c
@@ -136,11 +136,11 @@ static bool encl_ioc_add_pages(struct encl *encl, struct encl_segment *seg)
*/
uint64_t encl_get_entry(struct encl *encl, const char *symbol)
{
+ Elf64_Sym *symtab = NULL;
+ char *sym_names = NULL;
Elf64_Shdr *sections;
- Elf64_Sym *symtab;
Elf64_Ehdr *ehdr;
- char *sym_names;
- int num_sym;
+ int num_sym = 0;
int i;
ehdr = encl->bin;
@@ -161,6 +161,9 @@ uint64_t encl_get_entry(struct encl *encl, const char *symbol)
}
}
+ if (!symtab || !sym_names)
+ return 0;
+
for (i = 0; i < num_sym; i++) {
Elf64_Sym *sym = &symtab[i];
diff --git a/tools/testing/selftests/sgx/sigstruct.c b/tools/testing/selftests/sgx/sigstruct.c
index a07896a46364..d73b29becf5b 100644
--- a/tools/testing/selftests/sgx/sigstruct.c
+++ b/tools/testing/selftests/sgx/sigstruct.c
@@ -318,9 +318,9 @@ bool encl_measure(struct encl *encl)
struct sgx_sigstruct *sigstruct = &encl->sigstruct;
struct sgx_sigstruct_payload payload;
uint8_t digest[SHA256_DIGEST_LENGTH];
+ EVP_MD_CTX *ctx = NULL;
unsigned int siglen;
RSA *key = NULL;
- EVP_MD_CTX *ctx;
int i;
memset(sigstruct, 0, sizeof(*sigstruct));
@@ -384,7 +384,8 @@ bool encl_measure(struct encl *encl)
return true;
err:
- EVP_MD_CTX_destroy(ctx);
+ if (ctx)
+ EVP_MD_CTX_destroy(ctx);
RSA_free(key);
return false;
}
diff --git a/tools/testing/selftests/sgx/test_encl.c b/tools/testing/selftests/sgx/test_encl.c
index c0d6397295e3..2c4d709cce2d 100644
--- a/tools/testing/selftests/sgx/test_encl.c
+++ b/tools/testing/selftests/sgx/test_encl.c
@@ -5,11 +5,12 @@
#include "defines.h"
/*
- * Data buffer spanning two pages that will be placed first in .data
- * segment. Even if not used internally the second page is needed by
- * external test manipulating page permissions.
+ * Data buffer spanning two pages that will be placed first in the .data
+ * segment via the linker script. Even if not used internally the second page
+ * is needed by external test manipulating page permissions, so mark
+ * encl_buffer as "used" to make sure it is entirely preserved by the compiler.
*/
-static uint8_t encl_buffer[8192] = { 1 };
+static uint8_t __used __section(".data.encl_buffer") encl_buffer[8192] = { 1 };
enum sgx_enclu_function {
EACCEPT = 0x5,
@@ -24,10 +25,11 @@ static void do_encl_emodpe(void *_op)
secinfo.flags = op->flags;
asm volatile(".byte 0x0f, 0x01, 0xd7"
- :
+ : /* no outputs */
: "a" (EMODPE),
"b" (&secinfo),
- "c" (op->epc_addr));
+ "c" (op->epc_addr)
+ : "memory" /* read from secinfo pointer */);
}
static void do_encl_eaccept(void *_op)
@@ -42,7 +44,8 @@ static void do_encl_eaccept(void *_op)
: "=a" (rax)
: "a" (EACCEPT),
"b" (&secinfo),
- "c" (op->epc_addr));
+ "c" (op->epc_addr)
+ : "memory" /* read from secinfo pointer */);
op->ret = rax;
}
@@ -119,21 +122,41 @@ static void do_encl_op_nop(void *_op)
}
+/*
+ * Symbol placed at the start of the enclave image by the linker script.
+ * Declare this extern symbol with visibility "hidden" to ensure the compiler
+ * does not access it through the GOT and generates position-independent
+ * addressing as __encl_base(%rip), so we can get the actual enclave base
+ * during runtime.
+ */
+extern const uint8_t __attribute__((visibility("hidden"))) __encl_base;
+
+typedef void (*encl_op_t)(void *);
+static const encl_op_t encl_op_array[ENCL_OP_MAX] = {
+ do_encl_op_put_to_buf,
+ do_encl_op_get_from_buf,
+ do_encl_op_put_to_addr,
+ do_encl_op_get_from_addr,
+ do_encl_op_nop,
+ do_encl_eaccept,
+ do_encl_emodpe,
+ do_encl_init_tcs_page,
+};
+
void encl_body(void *rdi, void *rsi)
{
- const void (*encl_op_array[ENCL_OP_MAX])(void *) = {
- do_encl_op_put_to_buf,
- do_encl_op_get_from_buf,
- do_encl_op_put_to_addr,
- do_encl_op_get_from_addr,
- do_encl_op_nop,
- do_encl_eaccept,
- do_encl_emodpe,
- do_encl_init_tcs_page,
- };
-
- struct encl_op_header *op = (struct encl_op_header *)rdi;
-
- if (op->type < ENCL_OP_MAX)
- (*encl_op_array[op->type])(op);
+ struct encl_op_header *header = (struct encl_op_header *)rdi;
+ encl_op_t op;
+
+ if (header->type >= ENCL_OP_MAX)
+ return;
+
+ /*
+ * The enclave base address needs to be added, as this call site
+ * *cannot be* made rip-relative by the compiler, or fixed up by
+ * any other possible means.
+ */
+ op = ((uint64_t)&__encl_base) + encl_op_array[header->type];
+
+ (*op)(header);
}
diff --git a/tools/testing/selftests/sgx/test_encl.lds b/tools/testing/selftests/sgx/test_encl.lds
index a1ec64f7d91f..ffe851a1cac4 100644
--- a/tools/testing/selftests/sgx/test_encl.lds
+++ b/tools/testing/selftests/sgx/test_encl.lds
@@ -10,6 +10,7 @@ PHDRS
SECTIONS
{
. = 0;
+ __encl_base = .;
.tcs : {
*(.tcs*)
} : tcs
@@ -23,6 +24,7 @@ SECTIONS
} : text
.data : {
+ *(.data.encl_buffer)
*(.data*)
} : data
@@ -31,11 +33,9 @@ SECTIONS
*(.note*)
*(.debug*)
*(.eh_frame*)
+ *(.dyn*)
+ *(.gnu.hash)
}
}
-ASSERT(!DEFINED(.altinstructions), "ALTERNATIVES are not supported in enclaves")
-ASSERT(!DEFINED(.altinstr_replacement), "ALTERNATIVES are not supported in enclaves")
-ASSERT(!DEFINED(.discard.retpoline_safe), "RETPOLINE ALTERNATIVES are not supported in enclaves")
-ASSERT(!DEFINED(.discard.nospec), "RETPOLINE ALTERNATIVES are not supported in enclaves")
-ASSERT(!DEFINED(.got.plt), "Libcalls are not supported in enclaves")
+ASSERT(!DEFINED(_GLOBAL_OFFSET_TABLE_), "Libcalls through GOT are not supported in enclaves")
diff --git a/tools/testing/selftests/sgx/test_encl_bootstrap.S b/tools/testing/selftests/sgx/test_encl_bootstrap.S
index 03ae0f57e29d..d8c4ac94e032 100644
--- a/tools/testing/selftests/sgx/test_encl_bootstrap.S
+++ b/tools/testing/selftests/sgx/test_encl_bootstrap.S
@@ -42,9 +42,12 @@
encl_entry:
# RBX contains the base address for TCS, which is the first address
# inside the enclave for TCS #1 and one page into the enclave for
- # TCS #2. By adding the value of encl_stack to it, we get
- # the absolute address for the stack.
- lea (encl_stack)(%rbx), %rax
+ # TCS #2. First make it relative by substracting __encl_base and
+ # then add the address of encl_stack to get the address for the stack.
+ lea __encl_base(%rip), %rax
+ sub %rax, %rbx
+ lea encl_stack(%rip), %rax
+ add %rbx, %rax
jmp encl_entry_core
encl_dyn_entry:
# Entry point for dynamically created TCS page expected to follow
@@ -55,25 +58,12 @@ encl_entry_core:
push %rax
push %rcx # push the address after EENTER
- push %rbx # push the enclave base address
+ # NOTE: as the selftest enclave is *not* intended for production,
+ # simplify the code by not initializing ABI registers on entry or
+ # cleansing caller-save registers on exit.
call encl_body
- pop %rbx # pop the enclave base address
-
- /* Clear volatile GPRs, except RAX (EEXIT function). */
- xor %rcx, %rcx
- xor %rdx, %rdx
- xor %rdi, %rdi
- xor %rsi, %rsi
- xor %r8, %r8
- xor %r9, %r9
- xor %r10, %r10
- xor %r11, %r11
-
- # Reset status flags.
- add %rdx, %rdx # OF = SF = AF = CF = 0; ZF = PF = 1
-
# Prepare EEXIT target by popping the address of the instruction after
# EENTER to RBX.
pop %rbx