Re: [PATCH v6 11/11] lkdtm: Add test for XPFO

From: kbuild test robot
Date: Sat Sep 09 2017 - 21:02:07 EST

Hi Juerg,

[auto build test ERROR on arm64/for-next/core]
[also build test ERROR on v4.13]
[cannot apply to mmotm/master next-20170908]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url: https://github.com/0day-ci/linux/commits/Tycho-Andersen/Add-support-for-eXclusive-Page-Frame-Ownership/20170910-073030
base: https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/core
config: xtensa-allmodconfig (attached as .config)
compiler: xtensa-linux-gcc (GCC) 4.9.0
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=xtensa

All error/warnings (new ones prefixed by >>):

drivers/misc/lkdtm_xpfo.c: In function 'user_to_kernel':
>> drivers/misc/lkdtm_xpfo.c:54:2: error: implicit declaration of function 'phys_to_virt' [-Werror=implicit-function-declaration]
virt_addr = phys_to_virt(phys_addr);
^
drivers/misc/lkdtm_xpfo.c:54:12: warning: assignment makes pointer from integer without a cast
virt_addr = phys_to_virt(phys_addr);
^
>> drivers/misc/lkdtm_xpfo.c:55:2: error: implicit declaration of function 'virt_to_phys' [-Werror=implicit-function-declaration]
if (phys_addr != virt_to_phys(virt_addr)) {
^
drivers/misc/lkdtm_xpfo.c: At top level:
>> drivers/misc/lkdtm_xpfo.c:128:7: warning: "CONFIG_ARM64" is not defined [-Wundef]
#elif CONFIG_ARM64
^
>> drivers/misc/lkdtm_xpfo.c:131:2: error: #error unsupported arch
#error unsupported arch
^
drivers/misc/lkdtm_xpfo.c: In function 'lkdtm_XPFO_SMP':
>> drivers/misc/lkdtm_xpfo.c:191:13: error: 'XPFO_SMP_KILLED' undeclared (first use in this function)
if (ret != XPFO_SMP_KILLED)
^
drivers/misc/lkdtm_xpfo.c:191:13: note: each undeclared identifier is reported only once for each function it appears in
cc1: some warnings being treated as errors

vim +/phys_to_virt +54 drivers/misc/lkdtm_xpfo.c

42
43 static unsigned long *user_to_kernel(unsigned long user_addr)
44 {
45 phys_addr_t phys_addr;
46 void *virt_addr;
47
48 phys_addr = user_virt_to_phys(user_addr);
49 if (!phys_addr) {
50 pr_warn("Failed to get physical address of user memory\n");
51 return NULL;
52 }
53
> 54 virt_addr = phys_to_virt(phys_addr);
> 55 if (phys_addr != virt_to_phys(virt_addr)) {
56 pr_warn("Physical address of user memory seems incorrect\n");
57 return NULL;
58 }
59
60 return virt_addr;
61 }
62
63 static void read_map(unsigned long *virt_addr)
64 {
65 pr_info("Attempting bad read from kernel address %p\n", virt_addr);
66 if (*(unsigned long *)virt_addr == XPFO_DATA)
67 pr_err("FAIL: Bad read succeeded?!\n");
68 else
69 pr_err("FAIL: Bad read didn't fail but data is incorrect?!\n");
70 }
71
72 static void read_user_with_flags(unsigned long flags)
73 {
74 unsigned long user_addr, *kernel;
75
76 user_addr = do_map(flags);
77 if (!user_addr) {
78 pr_err("FAIL: map failed\n");
79 return;
80 }
81
82 kernel = user_to_kernel(user_addr);
83 if (!kernel) {
84 pr_err("FAIL: user to kernel conversion failed\n");
85 goto free_user;
86 }
87
88 read_map(kernel);
89
90 free_user:
91 vm_munmap(user_addr, PAGE_SIZE);
92 }
93
94 /* Read from userspace via the kernel's linear map. */
95 void lkdtm_XPFO_READ_USER(void)
96 {
97 read_user_with_flags(MAP_PRIVATE | MAP_ANONYMOUS);
98 }
99
100 void lkdtm_XPFO_READ_USER_HUGE(void)
101 {
102 read_user_with_flags(MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB);
103 }
104
105 struct smp_arg {
106 unsigned long *virt_addr;
107 unsigned int cpu;
108 };
109
110 static int smp_reader(void *parg)
111 {
112 struct smp_arg *arg = parg;
113 unsigned long *virt_addr;
114
115 if (arg->cpu != smp_processor_id()) {
116 pr_err("FAIL: scheduled on wrong CPU?\n");
117 return 0;
118 }
119
120 virt_addr = smp_cond_load_acquire(&arg->virt_addr, VAL != NULL);
121 read_map(virt_addr);
122
123 return 0;
124 }
125
126 #ifdef CONFIG_X86
127 #define XPFO_SMP_KILLED SIGKILL
> 128 #elif CONFIG_ARM64
129 #define XPFO_SMP_KILLED SIGSEGV
130 #else
> 131 #error unsupported arch
132 #endif
133
134 /* The idea here is to read from the kernel's map on a different thread than
135 * did the mapping (and thus the TLB flushing), to make sure that the page
136 * faults on other cores too.
137 */
138 void lkdtm_XPFO_SMP(void)
139 {
140 unsigned long user_addr, *virt_addr;
141 struct task_struct *thread;
142 int ret;
143 struct smp_arg arg;
144
145 if (num_online_cpus() < 2) {
146 pr_err("not enough to do a multi cpu test\n");
147 return;
148 }
149
150 arg.virt_addr = NULL;
151 arg.cpu = (smp_processor_id() + 1) % num_online_cpus();
152 thread = kthread_create(smp_reader, &arg, "lkdtm_xpfo_test");
153 if (IS_ERR(thread)) {
154 pr_err("couldn't create kthread? %ld\n", PTR_ERR(thread));
155 return;
156 }
157
158 kthread_bind(thread, arg.cpu);
159 get_task_struct(thread);
160 wake_up_process(thread);
161
162 user_addr = do_map(MAP_PRIVATE | MAP_ANONYMOUS);
163 if (!user_addr)
164 goto kill_thread;
165
166 virt_addr = user_to_kernel(user_addr);
167 if (!virt_addr) {
168 /*
169 * let's store something that will fail, so we can unblock the
170 * thread
171 */
172 smp_store_release(&arg.virt_addr, &arg);
173 goto free_user;
174 }
175
176 smp_store_release(&arg.virt_addr, virt_addr);
177
178 /* there must be a better way to do this. */
179 while (1) {
180 if (thread->exit_state)
181 break;
182 msleep_interruptible(100);
183 }
184
185 free_user:
186 if (user_addr)
187 vm_munmap(user_addr, PAGE_SIZE);
188
189 kill_thread:
190 ret = kthread_stop(thread);
> 191 if (ret != XPFO_SMP_KILLED)

---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation

Attachment: .config.gz
Description: application/gzip