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authorLinus Torvalds <torvalds@linux-foundation.org>2018-02-14 17:02:15 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2018-02-14 17:02:15 -0800
commitd4667ca142610961c89ae7c41a823b3358fcdd0e (patch)
treeff43d39e20feaf477a1ceaf35eba841eebd7e0a6 /tools
parent6556677a80400ca5744340d8ff6fbed22621293e (diff)
parente48657573481a5dff7cfdc3d57005c80aa816500 (diff)
downloadlinux-stericsson-d4667ca142610961c89ae7c41a823b3358fcdd0e.tar.gz
Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 PTI and Spectre related fixes and updates from Ingo Molnar: "Here's the latest set of Spectre and PTI related fixes and updates: Spectre: - Add entry code register clearing to reduce the Spectre attack surface - Update the Spectre microcode blacklist - Inline the KVM Spectre helpers to get close to v4.14 performance again. - Fix indirect_branch_prediction_barrier() - Fix/improve Spectre related kernel messages - Fix array_index_nospec_mask() asm constraint - KVM: fix two MSR handling bugs PTI: - Fix a paranoid entry PTI CR3 handling bug - Fix comments objtool: - Fix paranoid_entry() frame pointer warning - Annotate WARN()-related UD2 as reachable - Various fixes - Add Add Peter Zijlstra as objtool co-maintainer Misc: - Various x86 entry code self-test fixes - Improve/simplify entry code stack frame generation and handling after recent heavy-handed PTI and Spectre changes. (There's two more WIP improvements expected here.) - Type fix for cache entries There's also some low risk non-fix changes I've included in this branch to reduce backporting conflicts: - rename a confusing x86_cpu field name - de-obfuscate the naming of single-TLB flushing primitives" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits) x86/entry/64: Fix CR3 restore in paranoid_exit() x86/cpu: Change type of x86_cache_size variable to unsigned int x86/spectre: Fix an error message x86/cpu: Rename cpu_data.x86_mask to cpu_data.x86_stepping selftests/x86/mpx: Fix incorrect bounds with old _sigfault x86/mm: Rename flush_tlb_single() and flush_tlb_one() to __flush_tlb_one_[user|kernel]() x86/speculation: Add <asm/msr-index.h> dependency nospec: Move array_index_nospec() parameter checking into separate macro x86/speculation: Fix up array_index_nospec_mask() asm constraint x86/debug: Use UD2 for WARN() x86/debug, objtool: Annotate WARN()-related UD2 as reachable objtool: Fix segfault in ignore_unreachable_insn() selftests/x86: Disable tests requiring 32-bit support on pure 64-bit systems selftests/x86: Do not rely on "int $0x80" in single_step_syscall.c selftests/x86: Do not rely on "int $0x80" in test_mremap_vdso.c selftests/x86: Fix build bug caused by the 5lvl test which has been moved to the VM directory selftests/x86/pkeys: Remove unused functions selftests/x86: Clean up and document sscanf() usage selftests/x86: Fix vDSO selftest segfault for vsyscall=none x86/entry/64: Remove the unused 'icebp' macro ...
Diffstat (limited to 'tools')
-rw-r--r--tools/objtool/check.c53
-rw-r--r--tools/objtool/check.h1
-rw-r--r--tools/testing/selftests/x86/Makefile24
-rw-r--r--tools/testing/selftests/x86/mpx-mini-test.c32
-rw-r--r--tools/testing/selftests/x86/protection_keys.c28
-rw-r--r--tools/testing/selftests/x86/single_step_syscall.c5
-rw-r--r--tools/testing/selftests/x86/test_mremap_vdso.c4
-rw-r--r--tools/testing/selftests/x86/test_vdso.c55
-rw-r--r--tools/testing/selftests/x86/test_vsyscall.c11
9 files changed, 159 insertions, 54 deletions
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index b00b1896547e..a8cb69a26576 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -852,8 +852,14 @@ static int add_switch_table(struct objtool_file *file, struct symbol *func,
* This is a fairly uncommon pattern which is new for GCC 6. As of this
* writing, there are 11 occurrences of it in the allmodconfig kernel.
*
+ * As of GCC 7 there are quite a few more of these and the 'in between' code
+ * is significant. Esp. with KASAN enabled some of the code between the mov
+ * and jmpq uses .rodata itself, which can confuse things.
+ *
* TODO: Once we have DWARF CFI and smarter instruction decoding logic,
* ensure the same register is used in the mov and jump instructions.
+ *
+ * NOTE: RETPOLINE made it harder still to decode dynamic jumps.
*/
static struct rela *find_switch_table(struct objtool_file *file,
struct symbol *func,
@@ -875,12 +881,25 @@ static struct rela *find_switch_table(struct objtool_file *file,
text_rela->addend + 4);
if (!rodata_rela)
return NULL;
+
file->ignore_unreachables = true;
return rodata_rela;
}
/* case 3 */
- func_for_each_insn_continue_reverse(file, func, insn) {
+ /*
+ * Backward search using the @first_jump_src links, these help avoid
+ * much of the 'in between' code. Which avoids us getting confused by
+ * it.
+ */
+ for (insn = list_prev_entry(insn, list);
+
+ &insn->list != &file->insn_list &&
+ insn->sec == func->sec &&
+ insn->offset >= func->offset;
+
+ insn = insn->first_jump_src ?: list_prev_entry(insn, list)) {
+
if (insn->type == INSN_JUMP_DYNAMIC)
break;
@@ -910,14 +929,32 @@ static struct rela *find_switch_table(struct objtool_file *file,
return NULL;
}
+
static int add_func_switch_tables(struct objtool_file *file,
struct symbol *func)
{
- struct instruction *insn, *prev_jump = NULL;
+ struct instruction *insn, *last = NULL, *prev_jump = NULL;
struct rela *rela, *prev_rela = NULL;
int ret;
func_for_each_insn(file, func, insn) {
+ if (!last)
+ last = insn;
+
+ /*
+ * Store back-pointers for unconditional forward jumps such
+ * that find_switch_table() can back-track using those and
+ * avoid some potentially confusing code.
+ */
+ if (insn->type == INSN_JUMP_UNCONDITIONAL && insn->jump_dest &&
+ insn->offset > last->offset &&
+ insn->jump_dest->offset > insn->offset &&
+ !insn->jump_dest->first_jump_src) {
+
+ insn->jump_dest->first_jump_src = insn;
+ last = insn->jump_dest;
+ }
+
if (insn->type != INSN_JUMP_DYNAMIC)
continue;
@@ -1899,13 +1936,19 @@ static bool ignore_unreachable_insn(struct instruction *insn)
if (is_kasan_insn(insn) || is_ubsan_insn(insn))
return true;
- if (insn->type == INSN_JUMP_UNCONDITIONAL && insn->jump_dest) {
- insn = insn->jump_dest;
- continue;
+ if (insn->type == INSN_JUMP_UNCONDITIONAL) {
+ if (insn->jump_dest &&
+ insn->jump_dest->func == insn->func) {
+ insn = insn->jump_dest;
+ continue;
+ }
+
+ break;
}
if (insn->offset + insn->len >= insn->func->offset + insn->func->len)
break;
+
insn = list_next_entry(insn, list);
}
diff --git a/tools/objtool/check.h b/tools/objtool/check.h
index dbadb304a410..23a1d065cae1 100644
--- a/tools/objtool/check.h
+++ b/tools/objtool/check.h
@@ -47,6 +47,7 @@ struct instruction {
bool alt_group, visited, dead_end, ignore, hint, save, restore, ignore_alts;
struct symbol *call_dest;
struct instruction *jump_dest;
+ struct instruction *first_jump_src;
struct list_head alts;
struct symbol *func;
struct stack_op stack_op;
diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile
index 10ca46df1449..d744991c0f4f 100644
--- a/tools/testing/selftests/x86/Makefile
+++ b/tools/testing/selftests/x86/Makefile
@@ -5,16 +5,26 @@ include ../lib.mk
.PHONY: all all_32 all_64 warn_32bit_failure clean
-TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs syscall_nt ptrace_syscall test_mremap_vdso \
- check_initial_reg_state sigreturn ldt_gdt iopl mpx-mini-test ioperm \
+UNAME_M := $(shell uname -m)
+CAN_BUILD_I386 := $(shell ./check_cc.sh $(CC) trivial_32bit_program.c -m32)
+CAN_BUILD_X86_64 := $(shell ./check_cc.sh $(CC) trivial_64bit_program.c)
+
+TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs syscall_nt test_mremap_vdso \
+ check_initial_reg_state sigreturn iopl mpx-mini-test ioperm \
protection_keys test_vdso test_vsyscall
TARGETS_C_32BIT_ONLY := entry_from_vm86 syscall_arg_fault test_syscall_vdso unwind_vdso \
test_FCMOV test_FCOMI test_FISTTP \
vdso_restorer
-TARGETS_C_64BIT_ONLY := fsgsbase sysret_rip 5lvl
+TARGETS_C_64BIT_ONLY := fsgsbase sysret_rip
+# Some selftests require 32bit support enabled also on 64bit systems
+TARGETS_C_32BIT_NEEDED := ldt_gdt ptrace_syscall
-TARGETS_C_32BIT_ALL := $(TARGETS_C_BOTHBITS) $(TARGETS_C_32BIT_ONLY)
+TARGETS_C_32BIT_ALL := $(TARGETS_C_BOTHBITS) $(TARGETS_C_32BIT_ONLY) $(TARGETS_C_32BIT_NEEDED)
TARGETS_C_64BIT_ALL := $(TARGETS_C_BOTHBITS) $(TARGETS_C_64BIT_ONLY)
+ifeq ($(CAN_BUILD_I386)$(CAN_BUILD_X86_64),11)
+TARGETS_C_64BIT_ALL += $(TARGETS_C_32BIT_NEEDED)
+endif
+
BINARIES_32 := $(TARGETS_C_32BIT_ALL:%=%_32)
BINARIES_64 := $(TARGETS_C_64BIT_ALL:%=%_64)
@@ -23,10 +33,6 @@ BINARIES_64 := $(patsubst %,$(OUTPUT)/%,$(BINARIES_64))
CFLAGS := -O2 -g -std=gnu99 -pthread -Wall -no-pie
-UNAME_M := $(shell uname -m)
-CAN_BUILD_I386 := $(shell ./check_cc.sh $(CC) trivial_32bit_program.c -m32)
-CAN_BUILD_X86_64 := $(shell ./check_cc.sh $(CC) trivial_64bit_program.c)
-
define gen-target-rule-32
$(1) $(1)_32: $(OUTPUT)/$(1)_32
.PHONY: $(1) $(1)_32
@@ -40,12 +46,14 @@ endef
ifeq ($(CAN_BUILD_I386),1)
all: all_32
TEST_PROGS += $(BINARIES_32)
+EXTRA_CFLAGS += -DCAN_BUILD_32
$(foreach t,$(TARGETS_C_32BIT_ALL),$(eval $(call gen-target-rule-32,$(t))))
endif
ifeq ($(CAN_BUILD_X86_64),1)
all: all_64
TEST_PROGS += $(BINARIES_64)
+EXTRA_CFLAGS += -DCAN_BUILD_64
$(foreach t,$(TARGETS_C_64BIT_ALL),$(eval $(call gen-target-rule-64,$(t))))
endif
diff --git a/tools/testing/selftests/x86/mpx-mini-test.c b/tools/testing/selftests/x86/mpx-mini-test.c
index ec0f6b45ce8b..9c0325e1ea68 100644
--- a/tools/testing/selftests/x86/mpx-mini-test.c
+++ b/tools/testing/selftests/x86/mpx-mini-test.c
@@ -315,11 +315,39 @@ static inline void *__si_bounds_upper(siginfo_t *si)
return si->si_upper;
}
#else
+
+/*
+ * This deals with old version of _sigfault in some distros:
+ *
+
+old _sigfault:
+ struct {
+ void *si_addr;
+ } _sigfault;
+
+new _sigfault:
+ struct {
+ void __user *_addr;
+ int _trapno;
+ short _addr_lsb;
+ union {
+ struct {
+ void __user *_lower;
+ void __user *_upper;
+ } _addr_bnd;
+ __u32 _pkey;
+ };
+ } _sigfault;
+ *
+ */
+
static inline void **__si_bounds_hack(siginfo_t *si)
{
void *sigfault = &si->_sifields._sigfault;
void *end_sigfault = sigfault + sizeof(si->_sifields._sigfault);
- void **__si_lower = end_sigfault;
+ int *trapno = (int*)end_sigfault;
+ /* skip _trapno and _addr_lsb */
+ void **__si_lower = (void**)(trapno + 2);
return __si_lower;
}
@@ -331,7 +359,7 @@ static inline void *__si_bounds_lower(siginfo_t *si)
static inline void *__si_bounds_upper(siginfo_t *si)
{
- return (*__si_bounds_hack(si)) + sizeof(void *);
+ return *(__si_bounds_hack(si) + 1);
}
#endif
diff --git a/tools/testing/selftests/x86/protection_keys.c b/tools/testing/selftests/x86/protection_keys.c
index bc1b0735bb50..f15aa5a76fe3 100644
--- a/tools/testing/selftests/x86/protection_keys.c
+++ b/tools/testing/selftests/x86/protection_keys.c
@@ -393,34 +393,6 @@ pid_t fork_lazy_child(void)
return forkret;
}
-void davecmp(void *_a, void *_b, int len)
-{
- int i;
- unsigned long *a = _a;
- unsigned long *b = _b;
-
- for (i = 0; i < len / sizeof(*a); i++) {
- if (a[i] == b[i])
- continue;
-
- dprintf3("[%3d]: a: %016lx b: %016lx\n", i, a[i], b[i]);
- }
-}
-
-void dumpit(char *f)
-{
- int fd = open(f, O_RDONLY);
- char buf[100];
- int nr_read;
-
- dprintf2("maps fd: %d\n", fd);
- do {
- nr_read = read(fd, &buf[0], sizeof(buf));
- write(1, buf, nr_read);
- } while (nr_read > 0);
- close(fd);
-}
-
#define PKEY_DISABLE_ACCESS 0x1
#define PKEY_DISABLE_WRITE 0x2
diff --git a/tools/testing/selftests/x86/single_step_syscall.c b/tools/testing/selftests/x86/single_step_syscall.c
index a48da95c18fd..ddfdd635de16 100644
--- a/tools/testing/selftests/x86/single_step_syscall.c
+++ b/tools/testing/selftests/x86/single_step_syscall.c
@@ -119,7 +119,9 @@ static void check_result(void)
int main()
{
+#ifdef CAN_BUILD_32
int tmp;
+#endif
sethandler(SIGTRAP, sigtrap, 0);
@@ -139,12 +141,13 @@ int main()
: : "c" (post_nop) : "r11");
check_result();
#endif
-
+#ifdef CAN_BUILD_32
printf("[RUN]\tSet TF and check int80\n");
set_eflags(get_eflags() | X86_EFLAGS_TF);
asm volatile ("int $0x80" : "=a" (tmp) : "a" (SYS_getpid)
: INT80_CLOBBERS);
check_result();
+#endif
/*
* This test is particularly interesting if fast syscalls use
diff --git a/tools/testing/selftests/x86/test_mremap_vdso.c b/tools/testing/selftests/x86/test_mremap_vdso.c
index bf0d687c7db7..64f11c8d9b76 100644
--- a/tools/testing/selftests/x86/test_mremap_vdso.c
+++ b/tools/testing/selftests/x86/test_mremap_vdso.c
@@ -90,8 +90,12 @@ int main(int argc, char **argv, char **envp)
vdso_size += PAGE_SIZE;
}
+#ifdef __i386__
/* Glibc is likely to explode now - exit with raw syscall */
asm volatile ("int $0x80" : : "a" (__NR_exit), "b" (!!ret));
+#else /* __x86_64__ */
+ syscall(SYS_exit, ret);
+#endif
} else {
int status;
diff --git a/tools/testing/selftests/x86/test_vdso.c b/tools/testing/selftests/x86/test_vdso.c
index 29973cde06d3..235259011704 100644
--- a/tools/testing/selftests/x86/test_vdso.c
+++ b/tools/testing/selftests/x86/test_vdso.c
@@ -26,20 +26,59 @@
# endif
#endif
+/* max length of lines in /proc/self/maps - anything longer is skipped here */
+#define MAPS_LINE_LEN 128
+
int nerrs = 0;
+typedef long (*getcpu_t)(unsigned *, unsigned *, void *);
+
+getcpu_t vgetcpu;
+getcpu_t vdso_getcpu;
+
+static void *vsyscall_getcpu(void)
+{
#ifdef __x86_64__
-# define VSYS(x) (x)
+ FILE *maps;
+ char line[MAPS_LINE_LEN];
+ bool found = false;
+
+ maps = fopen("/proc/self/maps", "r");
+ if (!maps) /* might still be present, but ignore it here, as we test vDSO not vsyscall */
+ return NULL;
+
+ while (fgets(line, MAPS_LINE_LEN, maps)) {
+ char r, x;
+ void *start, *end;
+ char name[MAPS_LINE_LEN];
+
+ /* sscanf() is safe here as strlen(name) >= strlen(line) */
+ if (sscanf(line, "%p-%p %c-%cp %*x %*x:%*x %*u %s",
+ &start, &end, &r, &x, name) != 5)
+ continue;
+
+ if (strcmp(name, "[vsyscall]"))
+ continue;
+
+ /* assume entries are OK, as we test vDSO here not vsyscall */
+ found = true;
+ break;
+ }
+
+ fclose(maps);
+
+ if (!found) {
+ printf("Warning: failed to find vsyscall getcpu\n");
+ return NULL;
+ }
+ return (void *) (0xffffffffff600800);
#else
-# define VSYS(x) 0
+ return NULL;
#endif
+}
-typedef long (*getcpu_t)(unsigned *, unsigned *, void *);
-
-const getcpu_t vgetcpu = (getcpu_t)VSYS(0xffffffffff600800);
-getcpu_t vdso_getcpu;
-void fill_function_pointers()
+static void fill_function_pointers()
{
void *vdso = dlopen("linux-vdso.so.1",
RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
@@ -54,6 +93,8 @@ void fill_function_pointers()
vdso_getcpu = (getcpu_t)dlsym(vdso, "__vdso_getcpu");
if (!vdso_getcpu)
printf("Warning: failed to find getcpu in vDSO\n");
+
+ vgetcpu = (getcpu_t) vsyscall_getcpu();
}
static long sys_getcpu(unsigned * cpu, unsigned * node,
diff --git a/tools/testing/selftests/x86/test_vsyscall.c b/tools/testing/selftests/x86/test_vsyscall.c
index 7a744fa7b786..be81621446f0 100644
--- a/tools/testing/selftests/x86/test_vsyscall.c
+++ b/tools/testing/selftests/x86/test_vsyscall.c
@@ -33,6 +33,9 @@
# endif
#endif
+/* max length of lines in /proc/self/maps - anything longer is skipped here */
+#define MAPS_LINE_LEN 128
+
static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *),
int flags)
{
@@ -98,7 +101,7 @@ static int init_vsys(void)
#ifdef __x86_64__
int nerrs = 0;
FILE *maps;
- char line[128];
+ char line[MAPS_LINE_LEN];
bool found = false;
maps = fopen("/proc/self/maps", "r");
@@ -108,10 +111,12 @@ static int init_vsys(void)
return 0;
}
- while (fgets(line, sizeof(line), maps)) {
+ while (fgets(line, MAPS_LINE_LEN, maps)) {
char r, x;
void *start, *end;
- char name[128];
+ char name[MAPS_LINE_LEN];
+
+ /* sscanf() is safe here as strlen(name) >= strlen(line) */
if (sscanf(line, "%p-%p %c-%cp %*x %*x:%*x %*u %s",
&start, &end, &r, &x, name) != 5)
continue;