1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
2 From: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
3 Date: Fri, 27 Oct 2017 13:25:28 -0700
4 Subject: [PATCH] x86/mm: Relocate page fault error codes to traps.h
6 Content-Type: text/plain; charset=UTF-8
7 Content-Transfer-Encoding: 8bit
11 Up to this point, only fault.c used the definitions of the page fault error
12 codes. Thus, it made sense to keep them within such file. Other portions of
13 code might be interested in those definitions too. For instance, the User-
14 Mode Instruction Prevention emulation code will use such definitions to
15 emulate a page fault when it is unable to successfully copy the results
16 of the emulated instructions to user space.
18 While relocating the error code enumeration, the prefix X86_ is used to
19 make it consistent with the rest of the definitions in traps.h. Of course,
20 code using the enumeration had to be updated as well. No functional changes
23 Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
24 Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
25 Reviewed-by: Borislav Petkov <bp@suse.de>
26 Reviewed-by: Andy Lutomirski <luto@kernel.org>
27 Cc: "Michael S. Tsirkin" <mst@redhat.com>
28 Cc: Peter Zijlstra <peterz@infradead.org>
29 Cc: Dave Hansen <dave.hansen@linux.intel.com>
30 Cc: ricardo.neri@intel.com
31 Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
32 Cc: Huang Rui <ray.huang@amd.com>
33 Cc: Shuah Khan <shuah@kernel.org>
34 Cc: Jonathan Corbet <corbet@lwn.net>
35 Cc: Jiri Slaby <jslaby@suse.cz>
36 Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
37 Cc: Chris Metcalf <cmetcalf@mellanox.com>
38 Cc: Brian Gerst <brgerst@gmail.com>
39 Cc: Josh Poimboeuf <jpoimboe@redhat.com>
40 Cc: Chen Yucong <slaoub@gmail.com>
41 Cc: Vlastimil Babka <vbabka@suse.cz>
42 Cc: Masami Hiramatsu <mhiramat@kernel.org>
43 Cc: Paolo Bonzini <pbonzini@redhat.com>
44 Cc: Andrew Morton <akpm@linux-foundation.org>
45 Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
46 Link: https://lkml.kernel.org/r/1509135945-13762-2-git-send-email-ricardo.neri-calderon@linux.intel.com
48 (cherry picked from commit 1067f030994c69ca1fba8c607437c8895dcf8509)
49 Signed-off-by: Andy Whitcroft <apw@canonical.com>
50 Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
51 (cherry picked from commit a85a07ab9111e3c78797c20b60a664dbd5db4981)
52 Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
54 arch/x86/include/asm/traps.h | 18 +++++++++
55 arch/x86/mm/fault.c | 88 +++++++++++++++++---------------------------
56 2 files changed, 52 insertions(+), 54 deletions(-)
58 diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h
59 index feb89dbe359d..8e5bf86f87e5 100644
60 --- a/arch/x86/include/asm/traps.h
61 +++ b/arch/x86/include/asm/traps.h
62 @@ -162,4 +162,22 @@ enum {
63 X86_TRAP_IRET = 32, /* 32, IRET Exception */
67 + * Page fault error code bits:
69 + * bit 0 == 0: no page found 1: protection fault
70 + * bit 1 == 0: read access 1: write access
71 + * bit 2 == 0: kernel-mode access 1: user-mode access
72 + * bit 3 == 1: use of reserved bit detected
73 + * bit 4 == 1: fault was an instruction fetch
74 + * bit 5 == 1: protection keys block access
76 +enum x86_pf_error_code {
77 + X86_PF_PROT = 1 << 0,
78 + X86_PF_WRITE = 1 << 1,
79 + X86_PF_USER = 1 << 2,
80 + X86_PF_RSVD = 1 << 3,
81 + X86_PF_INSTR = 1 << 4,
84 #endif /* _ASM_X86_TRAPS_H */
85 diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
86 index 4ee9eb916826..d3a57e7ad311 100644
87 --- a/arch/x86/mm/fault.c
88 +++ b/arch/x86/mm/fault.c
90 #define CREATE_TRACE_POINTS
91 #include <asm/trace/exceptions.h>
94 - * Page fault error code bits:
96 - * bit 0 == 0: no page found 1: protection fault
97 - * bit 1 == 0: read access 1: write access
98 - * bit 2 == 0: kernel-mode access 1: user-mode access
99 - * bit 3 == 1: use of reserved bit detected
100 - * bit 4 == 1: fault was an instruction fetch
101 - * bit 5 == 1: protection keys block access
103 -enum x86_pf_error_code {
114 * Returns 0 if mmiotrace is disabled, or if the fault is not
115 * handled by mmiotrace:
116 @@ -149,7 +129,7 @@ is_prefetch(struct pt_regs *regs, unsigned long error_code, unsigned long addr)
117 * If it was a exec (instruction fetch) fault on NX page, then
118 * do not ignore the fault:
120 - if (error_code & PF_INSTR)
121 + if (error_code & X86_PF_INSTR)
124 instr = (void *)convert_ip_to_linear(current, regs);
125 @@ -179,7 +159,7 @@ is_prefetch(struct pt_regs *regs, unsigned long error_code, unsigned long addr)
126 * siginfo so userspace can discover which protection key was set
129 - * If we get here, we know that the hardware signaled a PF_PK
130 + * If we get here, we know that the hardware signaled a X86_PF_PK
131 * fault and that there was a VMA once we got in the fault
132 * handler. It does *not* guarantee that the VMA we find here
133 * was the one that we faulted on.
134 @@ -204,7 +184,7 @@ static void fill_sig_info_pkey(int si_code, siginfo_t *info, u32 *pkey)
136 * force_sig_info_fault() is called from a number of
137 * contexts, some of which have a VMA and some of which
138 - * do not. The PF_PK handing happens after we have a
139 + * do not. The X86_PF_PK handing happens after we have a
140 * valid VMA, so we should never reach this without a
143 @@ -693,7 +673,7 @@ show_fault_oops(struct pt_regs *regs, unsigned long error_code,
144 if (!oops_may_print())
147 - if (error_code & PF_INSTR) {
148 + if (error_code & X86_PF_INSTR) {
152 @@ -775,7 +755,7 @@ no_context(struct pt_regs *regs, unsigned long error_code,
154 if (current->thread.sig_on_uaccess_err && signal) {
155 tsk->thread.trap_nr = X86_TRAP_PF;
156 - tsk->thread.error_code = error_code | PF_USER;
157 + tsk->thread.error_code = error_code | X86_PF_USER;
158 tsk->thread.cr2 = address;
160 /* XXX: hwpoison faults will set the wrong code. */
161 @@ -894,7 +874,7 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
162 struct task_struct *tsk = current;
164 /* User mode accesses just cause a SIGSEGV */
165 - if (error_code & PF_USER) {
166 + if (error_code & X86_PF_USER) {
168 * It's possible to have interrupts off here:
170 @@ -915,7 +895,7 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
171 * Instruction fetch faults in the vsyscall page might need
174 - if (unlikely((error_code & PF_INSTR) &&
175 + if (unlikely((error_code & X86_PF_INSTR) &&
176 ((address & ~0xfff) == VSYSCALL_ADDR))) {
177 if (emulate_vsyscall(regs, address))
179 @@ -928,7 +908,7 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
180 * are always protection faults.
182 if (address >= TASK_SIZE_MAX)
183 - error_code |= PF_PROT;
184 + error_code |= X86_PF_PROT;
186 if (likely(show_unhandled_signals))
187 show_signal_msg(regs, error_code, address, tsk);
188 @@ -989,11 +969,11 @@ static inline bool bad_area_access_from_pkeys(unsigned long error_code,
190 if (!boot_cpu_has(X86_FEATURE_OSPKE))
192 - if (error_code & PF_PK)
193 + if (error_code & X86_PF_PK)
195 /* this checks permission keys on the VMA: */
196 - if (!arch_vma_access_permitted(vma, (error_code & PF_WRITE),
197 - (error_code & PF_INSTR), foreign))
198 + if (!arch_vma_access_permitted(vma, (error_code & X86_PF_WRITE),
199 + (error_code & X86_PF_INSTR), foreign))
203 @@ -1021,7 +1001,7 @@ do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address,
204 int code = BUS_ADRERR;
206 /* Kernel mode? Handle exceptions or die: */
207 - if (!(error_code & PF_USER)) {
208 + if (!(error_code & X86_PF_USER)) {
209 no_context(regs, error_code, address, SIGBUS, BUS_ADRERR);
212 @@ -1049,14 +1029,14 @@ static noinline void
213 mm_fault_error(struct pt_regs *regs, unsigned long error_code,
214 unsigned long address, u32 *pkey, unsigned int fault)
216 - if (fatal_signal_pending(current) && !(error_code & PF_USER)) {
217 + if (fatal_signal_pending(current) && !(error_code & X86_PF_USER)) {
218 no_context(regs, error_code, address, 0, 0);
222 if (fault & VM_FAULT_OOM) {
223 /* Kernel mode? Handle exceptions or die: */
224 - if (!(error_code & PF_USER)) {
225 + if (!(error_code & X86_PF_USER)) {
226 no_context(regs, error_code, address,
227 SIGSEGV, SEGV_MAPERR);
229 @@ -1081,16 +1061,16 @@ mm_fault_error(struct pt_regs *regs, unsigned long error_code,
231 static int spurious_fault_check(unsigned long error_code, pte_t *pte)
233 - if ((error_code & PF_WRITE) && !pte_write(*pte))
234 + if ((error_code & X86_PF_WRITE) && !pte_write(*pte))
237 - if ((error_code & PF_INSTR) && !pte_exec(*pte))
238 + if ((error_code & X86_PF_INSTR) && !pte_exec(*pte))
241 * Note: We do not do lazy flushing on protection key
242 - * changes, so no spurious fault will ever set PF_PK.
243 + * changes, so no spurious fault will ever set X86_PF_PK.
245 - if ((error_code & PF_PK))
246 + if ((error_code & X86_PF_PK))
250 @@ -1136,8 +1116,8 @@ spurious_fault(unsigned long error_code, unsigned long address)
251 * change, so user accesses are not expected to cause spurious
254 - if (error_code != (PF_WRITE | PF_PROT)
255 - && error_code != (PF_INSTR | PF_PROT))
256 + if (error_code != (X86_PF_WRITE | X86_PF_PROT) &&
257 + error_code != (X86_PF_INSTR | X86_PF_PROT))
260 pgd = init_mm.pgd + pgd_index(address);
261 @@ -1197,19 +1177,19 @@ access_error(unsigned long error_code, struct vm_area_struct *vma)
262 * always an unconditional error and can never result in
263 * a follow-up action to resolve the fault, like a COW.
265 - if (error_code & PF_PK)
266 + if (error_code & X86_PF_PK)
270 * Make sure to check the VMA so that we do not perform
271 - * faults just to hit a PF_PK as soon as we fill in a
272 + * faults just to hit a X86_PF_PK as soon as we fill in a
275 - if (!arch_vma_access_permitted(vma, (error_code & PF_WRITE),
276 - (error_code & PF_INSTR), foreign))
277 + if (!arch_vma_access_permitted(vma, (error_code & X86_PF_WRITE),
278 + (error_code & X86_PF_INSTR), foreign))
281 - if (error_code & PF_WRITE) {
282 + if (error_code & X86_PF_WRITE) {
283 /* write, present and write, not present: */
284 if (unlikely(!(vma->vm_flags & VM_WRITE)))
286 @@ -1217,7 +1197,7 @@ access_error(unsigned long error_code, struct vm_area_struct *vma)
290 - if (unlikely(error_code & PF_PROT))
291 + if (unlikely(error_code & X86_PF_PROT))
294 /* read, not present: */
295 @@ -1240,7 +1220,7 @@ static inline bool smap_violation(int error_code, struct pt_regs *regs)
296 if (!static_cpu_has(X86_FEATURE_SMAP))
299 - if (error_code & PF_USER)
300 + if (error_code & X86_PF_USER)
303 if (!user_mode(regs) && (regs->flags & X86_EFLAGS_AC))
304 @@ -1293,7 +1273,7 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,
305 * protection error (error_code & 9) == 0.
307 if (unlikely(fault_in_kernel_space(address))) {
308 - if (!(error_code & (PF_RSVD | PF_USER | PF_PROT))) {
309 + if (!(error_code & (X86_PF_RSVD | X86_PF_USER | X86_PF_PROT))) {
310 if (vmalloc_fault(address) >= 0)
313 @@ -1321,7 +1301,7 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,
314 if (unlikely(kprobes_fault(regs)))
317 - if (unlikely(error_code & PF_RSVD))
318 + if (unlikely(error_code & X86_PF_RSVD))
319 pgtable_bad(regs, error_code, address);
321 if (unlikely(smap_violation(error_code, regs))) {
322 @@ -1347,7 +1327,7 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,
324 if (user_mode(regs)) {
326 - error_code |= PF_USER;
327 + error_code |= X86_PF_USER;
328 flags |= FAULT_FLAG_USER;
330 if (regs->flags & X86_EFLAGS_IF)
331 @@ -1356,9 +1336,9 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,
333 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
335 - if (error_code & PF_WRITE)
336 + if (error_code & X86_PF_WRITE)
337 flags |= FAULT_FLAG_WRITE;
338 - if (error_code & PF_INSTR)
339 + if (error_code & X86_PF_INSTR)
340 flags |= FAULT_FLAG_INSTRUCTION;
343 @@ -1378,7 +1358,7 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,
344 * space check, thus avoiding the deadlock:
346 if (unlikely(!down_read_trylock(&mm->mmap_sem))) {
347 - if ((error_code & PF_USER) == 0 &&
348 + if (!(error_code & X86_PF_USER) &&
349 !search_exception_tables(regs->ip)) {
350 bad_area_nosemaphore(regs, error_code, address, NULL);
352 @@ -1405,7 +1385,7 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,
353 bad_area(regs, error_code, address);
356 - if (error_code & PF_USER) {
357 + if (error_code & X86_PF_USER) {
359 * Accessing the stack below %sp is always a bug.
360 * The large cushion allows instructions like enter