Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
+76
-55
+8
-6
tools/testing/selftests/sgx/Makefile
+8
-6
tools/testing/selftests/sgx/Makefile
···
12
12
endif
13
13
14
14
INCLUDES := -I$(top_srcdir)/tools/include
15
-
HOST_CFLAGS := -Wall -Werror -g $(INCLUDES) -fPIC -z noexecstack
16
-
ENCL_CFLAGS := -Wall -Werror -static -nostdlib -nostartfiles -fPIC \
15
+
HOST_CFLAGS := -Wall -Werror -g $(INCLUDES) -fPIC
16
+
HOST_LDFLAGS := -z noexecstack -lcrypto
17
+
ENCL_CFLAGS += -Wall -Werror -static-pie -nostdlib -ffreestanding -fPIE \
17
18
-fno-stack-protector -mrdrnd $(INCLUDES)
19
+
ENCL_LDFLAGS := -Wl,-T,test_encl.lds,--build-id=none
18
20
21
+
ifeq ($(CAN_BUILD_X86_64), 1)
19
22
TEST_CUSTOM_PROGS := $(OUTPUT)/test_sgx
20
23
TEST_FILES := $(OUTPUT)/test_encl.elf
21
24
22
-
ifeq ($(CAN_BUILD_X86_64), 1)
23
25
all: $(TEST_CUSTOM_PROGS) $(OUTPUT)/test_encl.elf
24
26
endif
25
27
···
30
28
$(OUTPUT)/sigstruct.o \
31
29
$(OUTPUT)/call.o \
32
30
$(OUTPUT)/sign_key.o
33
-
$(CC) $(HOST_CFLAGS) -o $@ $^ -lcrypto
31
+
$(CC) $(HOST_CFLAGS) -o $@ $^ $(HOST_LDFLAGS)
34
32
35
33
$(OUTPUT)/main.o: main.c
36
34
$(CC) $(HOST_CFLAGS) -c $< -o $@
···
47
45
$(OUTPUT)/sign_key.o: sign_key.S
48
46
$(CC) $(HOST_CFLAGS) -c $< -o $@
49
47
50
-
$(OUTPUT)/test_encl.elf: test_encl.lds test_encl.c test_encl_bootstrap.S
51
-
$(CC) $(ENCL_CFLAGS) -T $^ -o $@ -Wl,--build-id=none
48
+
$(OUTPUT)/test_encl.elf: test_encl.c test_encl_bootstrap.S
49
+
$(CC) $(ENCL_CFLAGS) $^ -o $@ $(ENCL_LDFLAGS)
52
50
53
51
EXTRA_CLEAN := \
54
52
$(OUTPUT)/test_encl.elf \
+2
tools/testing/selftests/sgx/defines.h
+2
tools/testing/selftests/sgx/defines.h
···
13
13
14
14
#define __aligned(x) __attribute__((__aligned__(x)))
15
15
#define __packed __attribute__((packed))
16
+
#define __used __attribute__((used))
17
+
#define __section(x)__attribute__((__section__(x)))
16
18
17
19
#include "../../../../arch/x86/include/asm/sgx.h"
18
20
#include "../../../../arch/x86/include/asm/enclu.h"
+6
-3
tools/testing/selftests/sgx/load.c
+6
-3
tools/testing/selftests/sgx/load.c
···
136
136
*/
137
137
uint64_t encl_get_entry(struct encl *encl, const char *symbol)
138
138
{
139
+
Elf64_Sym *symtab = NULL;
140
+
char *sym_names = NULL;
139
141
Elf64_Shdr *sections;
140
-
Elf64_Sym *symtab;
141
142
Elf64_Ehdr *ehdr;
142
-
char *sym_names;
143
-
int num_sym;
143
+
int num_sym = 0;
144
144
int i;
145
145
146
146
ehdr = encl->bin;
···
160
160
break;
161
161
}
162
162
}
163
+
164
+
if (!symtab || !sym_names)
165
+
return 0;
163
166
164
167
for (i = 0; i < num_sym; i++) {
165
168
Elf64_Sym *sym = &symtab[i];
+3
-2
tools/testing/selftests/sgx/sigstruct.c
+3
-2
tools/testing/selftests/sgx/sigstruct.c
···
318
318
struct sgx_sigstruct *sigstruct = &encl->sigstruct;
319
319
struct sgx_sigstruct_payload payload;
320
320
uint8_t digest[SHA256_DIGEST_LENGTH];
321
+
EVP_MD_CTX *ctx = NULL;
321
322
unsigned int siglen;
322
323
RSA *key = NULL;
323
-
EVP_MD_CTX *ctx;
324
324
int i;
325
325
326
326
memset(sigstruct, 0, sizeof(*sigstruct));
···
384
384
return true;
385
385
386
386
err:
387
-
EVP_MD_CTX_destroy(ctx);
387
+
if (ctx)
388
+
EVP_MD_CTX_destroy(ctx);
388
389
RSA_free(key);
389
390
return false;
390
391
}
+43
-20
tools/testing/selftests/sgx/test_encl.c
+43
-20
tools/testing/selftests/sgx/test_encl.c
···
5
5
#include "defines.h"
6
6
7
7
/*
8
-
* Data buffer spanning two pages that will be placed first in .data
9
-
* segment. Even if not used internally the second page is needed by
10
-
* external test manipulating page permissions.
8
+
* Data buffer spanning two pages that will be placed first in the .data
9
+
* segment via the linker script. Even if not used internally the second page
10
+
* is needed by external test manipulating page permissions, so mark
11
+
* encl_buffer as "used" to make sure it is entirely preserved by the compiler.
11
12
*/
12
-
static uint8_t encl_buffer[8192] = { 1 };
13
+
static uint8_t __used __section(".data.encl_buffer") encl_buffer[8192] = { 1 };
13
14
14
15
enum sgx_enclu_function {
15
16
EACCEPT = 0x5,
···
25
24
secinfo.flags = op->flags;
26
25
27
26
asm volatile(".byte 0x0f, 0x01, 0xd7"
28
-
:
27
+
: /* no outputs */
29
28
: "a" (EMODPE),
30
29
"b" (&secinfo),
31
-
"c" (op->epc_addr));
30
+
"c" (op->epc_addr)
31
+
: "memory" /* read from secinfo pointer */);
32
32
}
33
33
34
34
static void do_encl_eaccept(void *_op)
···
44
42
: "=a" (rax)
45
43
: "a" (EACCEPT),
46
44
"b" (&secinfo),
47
-
"c" (op->epc_addr));
45
+
"c" (op->epc_addr)
46
+
: "memory" /* read from secinfo pointer */);
48
47
49
48
op->ret = rax;
50
49
}
···
122
119
123
120
}
124
121
122
+
/*
123
+
* Symbol placed at the start of the enclave image by the linker script.
124
+
* Declare this extern symbol with visibility "hidden" to ensure the compiler
125
+
* does not access it through the GOT and generates position-independent
126
+
* addressing as __encl_base(%rip), so we can get the actual enclave base
127
+
* during runtime.
128
+
*/
129
+
extern const uint8_t __attribute__((visibility("hidden"))) __encl_base;
130
+
131
+
typedef void (*encl_op_t)(void *);
132
+
static const encl_op_t encl_op_array[ENCL_OP_MAX] = {
133
+
do_encl_op_put_to_buf,
134
+
do_encl_op_get_from_buf,
135
+
do_encl_op_put_to_addr,
136
+
do_encl_op_get_from_addr,
137
+
do_encl_op_nop,
138
+
do_encl_eaccept,
139
+
do_encl_emodpe,
140
+
do_encl_init_tcs_page,
141
+
};
142
+
125
143
void encl_body(void *rdi, void *rsi)
126
144
{
127
-
const void (*encl_op_array[ENCL_OP_MAX])(void *) = {
128
-
do_encl_op_put_to_buf,
129
-
do_encl_op_get_from_buf,
130
-
do_encl_op_put_to_addr,
131
-
do_encl_op_get_from_addr,
132
-
do_encl_op_nop,
133
-
do_encl_eaccept,
134
-
do_encl_emodpe,
135
-
do_encl_init_tcs_page,
136
-
};
145
+
struct encl_op_header *header = (struct encl_op_header *)rdi;
146
+
encl_op_t op;
137
147
138
-
struct encl_op_header *op = (struct encl_op_header *)rdi;
148
+
if (header->type >= ENCL_OP_MAX)
149
+
return;
139
150
140
-
if (op->type < ENCL_OP_MAX)
141
-
(*encl_op_array[op->type])(op);
151
+
/*
152
+
* The enclave base address needs to be added, as this call site
153
+
* *cannot be* made rip-relative by the compiler, or fixed up by
154
+
* any other possible means.
155
+
*/
156
+
op = ((uint64_t)&__encl_base) + encl_op_array[header->type];
157
+
158
+
(*op)(header);
142
159
}
+5
-5
tools/testing/selftests/sgx/test_encl.lds
+5
-5
tools/testing/selftests/sgx/test_encl.lds
···
10
10
SECTIONS
11
11
{
12
12
. = 0;
13
+
__encl_base = .;
13
14
.tcs : {
14
15
*(.tcs*)
15
16
} : tcs
···
24
23
} : text
25
24
26
25
.data : {
26
+
*(.data.encl_buffer)
27
27
*(.data*)
28
28
} : data
29
29
···
33
31
*(.note*)
34
32
*(.debug*)
35
33
*(.eh_frame*)
34
+
*(.dyn*)
35
+
*(.gnu.hash)
36
36
}
37
37
}
38
38
39
-
ASSERT(!DEFINED(.altinstructions), "ALTERNATIVES are not supported in enclaves")
40
-
ASSERT(!DEFINED(.altinstr_replacement), "ALTERNATIVES are not supported in enclaves")
41
-
ASSERT(!DEFINED(.discard.retpoline_safe), "RETPOLINE ALTERNATIVES are not supported in enclaves")
42
-
ASSERT(!DEFINED(.discard.nospec), "RETPOLINE ALTERNATIVES are not supported in enclaves")
43
-
ASSERT(!DEFINED(.got.plt), "Libcalls are not supported in enclaves")
39
+
ASSERT(!DEFINED(_GLOBAL_OFFSET_TABLE_), "Libcalls through GOT are not supported in enclaves")
+9
-19
tools/testing/selftests/sgx/test_encl_bootstrap.S
+9
-19
tools/testing/selftests/sgx/test_encl_bootstrap.S
···
42
42
encl_entry:
43
43
# RBX contains the base address for TCS, which is the first address
44
44
# inside the enclave for TCS #1 and one page into the enclave for
45
-
# TCS #2. By adding the value of encl_stack to it, we get
46
-
# the absolute address for the stack.
47
-
lea (encl_stack)(%rbx), %rax
45
+
# TCS #2. First make it relative by substracting __encl_base and
46
+
# then add the address of encl_stack to get the address for the stack.
47
+
lea __encl_base(%rip), %rax
48
+
sub %rax, %rbx
49
+
lea encl_stack(%rip), %rax
50
+
add %rbx, %rax
48
51
jmp encl_entry_core
49
52
encl_dyn_entry:
50
53
# Entry point for dynamically created TCS page expected to follow
···
58
55
push %rax
59
56
60
57
push %rcx # push the address after EENTER
61
-
push %rbx # push the enclave base address
62
58
59
+
# NOTE: as the selftest enclave is *not* intended for production,
60
+
# simplify the code by not initializing ABI registers on entry or
61
+
# cleansing caller-save registers on exit.
63
62
call encl_body
64
-
65
-
pop %rbx # pop the enclave base address
66
-
67
-
/* Clear volatile GPRs, except RAX (EEXIT function). */
68
-
xor %rcx, %rcx
69
-
xor %rdx, %rdx
70
-
xor %rdi, %rdi
71
-
xor %rsi, %rsi
72
-
xor %r8, %r8
73
-
xor %r9, %r9
74
-
xor %r10, %r10
75
-
xor %r11, %r11
76
-
77
-
# Reset status flags.
78
-
add %rdx, %rdx # OF = SF = AF = CF = 0; ZF = PF = 1
79
63
80
64
# Prepare EEXIT target by popping the address of the instruction after
81
65
# EENTER to RBX.