Showing error 1781

User: Jiri Slaby
Error type: Invalid Pointer Dereference
Error type description: A pointer which is invalid is being dereferenced
File location: arch/x86/kernel/efi.c
Line in file: 354
Project: Linux Kernel
Project version: 2.6.28
Tools: Smatch (1.59)
Entered: 2013-09-11 08:47:26 UTC


Source:

  1/*
  2 * Common EFI (Extensible Firmware Interface) support functions
  3 * Based on Extensible Firmware Interface Specification version 1.0
  4 *
  5 * Copyright (C) 1999 VA Linux Systems
  6 * Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
  7 * Copyright (C) 1999-2002 Hewlett-Packard Co.
  8 *        David Mosberger-Tang <davidm@hpl.hp.com>
  9 *        Stephane Eranian <eranian@hpl.hp.com>
 10 * Copyright (C) 2005-2008 Intel Co.
 11 *        Fenghua Yu <fenghua.yu@intel.com>
 12 *        Bibo Mao <bibo.mao@intel.com>
 13 *        Chandramouli Narayanan <mouli@linux.intel.com>
 14 *        Huang Ying <ying.huang@intel.com>
 15 *
 16 * Copied from efi_32.c to eliminate the duplicated code between EFI
 17 * 32/64 support code. --ying 2007-10-26
 18 *
 19 * All EFI Runtime Services are not implemented yet as EFI only
 20 * supports physical mode addressing on SoftSDV. This is to be fixed
 21 * in a future version.  --drummond 1999-07-20
 22 *
 23 * Implemented EFI runtime services and virtual mode calls.  --davidm
 24 *
 25 * Goutham Rao: <goutham.rao@intel.com>
 26 *        Skip non-WB memory and ignore empty memory ranges.
 27 */
 28
 29#include <linux/kernel.h>
 30#include <linux/init.h>
 31#include <linux/efi.h>
 32#include <linux/bootmem.h>
 33#include <linux/spinlock.h>
 34#include <linux/uaccess.h>
 35#include <linux/time.h>
 36#include <linux/io.h>
 37#include <linux/reboot.h>
 38#include <linux/bcd.h>
 39
 40#include <asm/setup.h>
 41#include <asm/efi.h>
 42#include <asm/time.h>
 43#include <asm/cacheflush.h>
 44#include <asm/tlbflush.h>
 45
 46#define EFI_DEBUG        1
 47#define PFX                 "EFI: "
 48
 49int efi_enabled;
 50EXPORT_SYMBOL(efi_enabled);
 51
 52struct efi efi;
 53EXPORT_SYMBOL(efi);
 54
 55struct efi_memory_map memmap;
 56
 57static struct efi efi_phys __initdata;
 58static efi_system_table_t efi_systab __initdata;
 59
 60static int __init setup_noefi(char *arg)
 61{
 62        efi_enabled = 0;
 63        return 0;
 64}
 65early_param("noefi", setup_noefi);
 66
 67int add_efi_memmap;
 68EXPORT_SYMBOL(add_efi_memmap);
 69
 70static int __init setup_add_efi_memmap(char *arg)
 71{
 72        add_efi_memmap = 1;
 73        return 0;
 74}
 75early_param("add_efi_memmap", setup_add_efi_memmap);
 76
 77
 78static efi_status_t virt_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc)
 79{
 80        return efi_call_virt2(get_time, tm, tc);
 81}
 82
 83static efi_status_t virt_efi_set_time(efi_time_t *tm)
 84{
 85        return efi_call_virt1(set_time, tm);
 86}
 87
 88static efi_status_t virt_efi_get_wakeup_time(efi_bool_t *enabled,
 89                                             efi_bool_t *pending,
 90                                             efi_time_t *tm)
 91{
 92        return efi_call_virt3(get_wakeup_time,
 93                              enabled, pending, tm);
 94}
 95
 96static efi_status_t virt_efi_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
 97{
 98        return efi_call_virt2(set_wakeup_time,
 99                              enabled, tm);
100}
101
102static efi_status_t virt_efi_get_variable(efi_char16_t *name,
103                                          efi_guid_t *vendor,
104                                          u32 *attr,
105                                          unsigned long *data_size,
106                                          void *data)
107{
108        return efi_call_virt5(get_variable,
109                              name, vendor, attr,
110                              data_size, data);
111}
112
113static efi_status_t virt_efi_get_next_variable(unsigned long *name_size,
114                                               efi_char16_t *name,
115                                               efi_guid_t *vendor)
116{
117        return efi_call_virt3(get_next_variable,
118                              name_size, name, vendor);
119}
120
121static efi_status_t virt_efi_set_variable(efi_char16_t *name,
122                                          efi_guid_t *vendor,
123                                          unsigned long attr,
124                                          unsigned long data_size,
125                                          void *data)
126{
127        return efi_call_virt5(set_variable,
128                              name, vendor, attr,
129                              data_size, data);
130}
131
132static efi_status_t virt_efi_get_next_high_mono_count(u32 *count)
133{
134        return efi_call_virt1(get_next_high_mono_count, count);
135}
136
137static void virt_efi_reset_system(int reset_type,
138                                  efi_status_t status,
139                                  unsigned long data_size,
140                                  efi_char16_t *data)
141{
142        efi_call_virt4(reset_system, reset_type, status,
143                       data_size, data);
144}
145
146static efi_status_t virt_efi_set_virtual_address_map(
147        unsigned long memory_map_size,
148        unsigned long descriptor_size,
149        u32 descriptor_version,
150        efi_memory_desc_t *virtual_map)
151{
152        return efi_call_virt4(set_virtual_address_map,
153                              memory_map_size, descriptor_size,
154                              descriptor_version, virtual_map);
155}
156
157static efi_status_t __init phys_efi_set_virtual_address_map(
158        unsigned long memory_map_size,
159        unsigned long descriptor_size,
160        u32 descriptor_version,
161        efi_memory_desc_t *virtual_map)
162{
163        efi_status_t status;
164
165        efi_call_phys_prelog();
166        status = efi_call_phys4(efi_phys.set_virtual_address_map,
167                                memory_map_size, descriptor_size,
168                                descriptor_version, virtual_map);
169        efi_call_phys_epilog();
170        return status;
171}
172
173static efi_status_t __init phys_efi_get_time(efi_time_t *tm,
174                                             efi_time_cap_t *tc)
175{
176        efi_status_t status;
177
178        efi_call_phys_prelog();
179        status = efi_call_phys2(efi_phys.get_time, tm, tc);
180        efi_call_phys_epilog();
181        return status;
182}
183
184int efi_set_rtc_mmss(unsigned long nowtime)
185{
186        int real_seconds, real_minutes;
187        efi_status_t         status;
188        efi_time_t         eft;
189        efi_time_cap_t         cap;
190
191        status = efi.get_time(&eft, &cap);
192        if (status != EFI_SUCCESS) {
193                printk(KERN_ERR "Oops: efitime: can't read time!\n");
194                return -1;
195        }
196
197        real_seconds = nowtime % 60;
198        real_minutes = nowtime / 60;
199        if (((abs(real_minutes - eft.minute) + 15)/30) & 1)
200                real_minutes += 30;
201        real_minutes %= 60;
202        eft.minute = real_minutes;
203        eft.second = real_seconds;
204
205        status = efi.set_time(&eft);
206        if (status != EFI_SUCCESS) {
207                printk(KERN_ERR "Oops: efitime: can't write time!\n");
208                return -1;
209        }
210        return 0;
211}
212
213unsigned long efi_get_time(void)
214{
215        efi_status_t status;
216        efi_time_t eft;
217        efi_time_cap_t cap;
218
219        status = efi.get_time(&eft, &cap);
220        if (status != EFI_SUCCESS)
221                printk(KERN_ERR "Oops: efitime: can't read time!\n");
222
223        return mktime(eft.year, eft.month, eft.day, eft.hour,
224                      eft.minute, eft.second);
225}
226
227/*
228 * Tell the kernel about the EFI memory map.  This might include
229 * more than the max 128 entries that can fit in the e820 legacy
230 * (zeropage) memory map.
231 */
232
233static void __init do_add_efi_memmap(void)
234{
235        void *p;
236
237        for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
238                efi_memory_desc_t *md = p;
239                unsigned long long start = md->phys_addr;
240                unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
241                int e820_type;
242
243                if (md->attribute & EFI_MEMORY_WB)
244                        e820_type = E820_RAM;
245                else
246                        e820_type = E820_RESERVED;
247                e820_add_region(start, size, e820_type);
248        }
249        sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
250}
251
252void __init efi_reserve_early(void)
253{
254        unsigned long pmap;
255
256#ifdef CONFIG_X86_32
257        pmap = boot_params.efi_info.efi_memmap;
258#else
259        pmap = (boot_params.efi_info.efi_memmap |
260                ((__u64)boot_params.efi_info.efi_memmap_hi<<32));
261#endif
262        memmap.phys_map = (void *)pmap;
263        memmap.nr_map = boot_params.efi_info.efi_memmap_size /
264                boot_params.efi_info.efi_memdesc_size;
265        memmap.desc_version = boot_params.efi_info.efi_memdesc_version;
266        memmap.desc_size = boot_params.efi_info.efi_memdesc_size;
267        reserve_early(pmap, pmap + memmap.nr_map * memmap.desc_size,
268                      "EFI memmap");
269}
270
271#if EFI_DEBUG
272static void __init print_efi_memmap(void)
273{
274        efi_memory_desc_t *md;
275        void *p;
276        int i;
277
278        for (p = memmap.map, i = 0;
279             p < memmap.map_end;
280             p += memmap.desc_size, i++) {
281                md = p;
282                printk(KERN_INFO PFX "mem%02u: type=%u, attr=0x%llx, "
283                        "range=[0x%016llx-0x%016llx) (%lluMB)\n",
284                        i, md->type, md->attribute, md->phys_addr,
285                        md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT),
286                        (md->num_pages >> (20 - EFI_PAGE_SHIFT)));
287        }
288}
289#endif  /*  EFI_DEBUG  */
290
291void __init efi_init(void)
292{
293        efi_config_table_t *config_tables;
294        efi_runtime_services_t *runtime;
295        efi_char16_t *c16;
296        char vendor[100] = "unknown";
297        int i = 0;
298        void *tmp;
299
300#ifdef CONFIG_X86_32
301        efi_phys.systab = (efi_system_table_t *)boot_params.efi_info.efi_systab;
302#else
303        efi_phys.systab = (efi_system_table_t *)
304                (boot_params.efi_info.efi_systab |
305                 ((__u64)boot_params.efi_info.efi_systab_hi<<32));
306#endif
307
308        efi.systab = early_ioremap((unsigned long)efi_phys.systab,
309                                   sizeof(efi_system_table_t));
310        if (efi.systab == NULL)
311                printk(KERN_ERR "Couldn't map the EFI system table!\n");
312        memcpy(&efi_systab, efi.systab, sizeof(efi_system_table_t));
313        early_iounmap(efi.systab, sizeof(efi_system_table_t));
314        efi.systab = &efi_systab;
315
316        /*
317         * Verify the EFI Table
318         */
319        if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
320                printk(KERN_ERR "EFI system table signature incorrect!\n");
321        if ((efi.systab->hdr.revision >> 16) == 0)
322                printk(KERN_ERR "Warning: EFI system table version "
323                       "%d.%02d, expected 1.00 or greater!\n",
324                       efi.systab->hdr.revision >> 16,
325                       efi.systab->hdr.revision & 0xffff);
326
327        /*
328         * Show what we know for posterity
329         */
330        c16 = tmp = early_ioremap(efi.systab->fw_vendor, 2);
331        if (c16) {
332                for (i = 0; i < sizeof(vendor) && *c16; ++i)
333                        vendor[i] = *c16++;
334                vendor[i] = '\0';
335        } else
336                printk(KERN_ERR PFX "Could not map the firmware vendor!\n");
337        early_iounmap(tmp, 2);
338
339        printk(KERN_INFO "EFI v%u.%.02u by %s \n",
340               efi.systab->hdr.revision >> 16,
341               efi.systab->hdr.revision & 0xffff, vendor);
342
343        /*
344         * Let's see what config tables the firmware passed to us.
345         */
346        config_tables = early_ioremap(
347                efi.systab->tables,
348                efi.systab->nr_tables * sizeof(efi_config_table_t));
349        if (config_tables == NULL)
350                printk(KERN_ERR "Could not map EFI Configuration Table!\n");
351
352        printk(KERN_INFO);
353        for (i = 0; i < efi.systab->nr_tables; i++) {
354                if (!efi_guidcmp(config_tables[i].guid, MPS_TABLE_GUID)) {
355                        efi.mps = config_tables[i].table;
356                        printk(" MPS=0x%lx ", config_tables[i].table);
357                } else if (!efi_guidcmp(config_tables[i].guid,
358                                        ACPI_20_TABLE_GUID)) {
359                        efi.acpi20 = config_tables[i].table;
360                        printk(" ACPI 2.0=0x%lx ", config_tables[i].table);
361                } else if (!efi_guidcmp(config_tables[i].guid,
362                                        ACPI_TABLE_GUID)) {
363                        efi.acpi = config_tables[i].table;
364                        printk(" ACPI=0x%lx ", config_tables[i].table);
365                } else if (!efi_guidcmp(config_tables[i].guid,
366                                        SMBIOS_TABLE_GUID)) {
367                        efi.smbios = config_tables[i].table;
368                        printk(" SMBIOS=0x%lx ", config_tables[i].table);
369                } else if (!efi_guidcmp(config_tables[i].guid,
370                                        UV_SYSTEM_TABLE_GUID)) {
371                        efi.uv_systab = config_tables[i].table;
372                        printk(" UVsystab=0x%lx ", config_tables[i].table);
373                } else if (!efi_guidcmp(config_tables[i].guid,
374                                        HCDP_TABLE_GUID)) {
375                        efi.hcdp = config_tables[i].table;
376                        printk(" HCDP=0x%lx ", config_tables[i].table);
377                } else if (!efi_guidcmp(config_tables[i].guid,
378                                        UGA_IO_PROTOCOL_GUID)) {
379                        efi.uga = config_tables[i].table;
380                        printk(" UGA=0x%lx ", config_tables[i].table);
381                }
382        }
383        printk("\n");
384        early_iounmap(config_tables,
385                          efi.systab->nr_tables * sizeof(efi_config_table_t));
386
387        /*
388         * Check out the runtime services table. We need to map
389         * the runtime services table so that we can grab the physical
390         * address of several of the EFI runtime functions, needed to
391         * set the firmware into virtual mode.
392         */
393        runtime = early_ioremap((unsigned long)efi.systab->runtime,
394                                sizeof(efi_runtime_services_t));
395        if (runtime != NULL) {
396                /*
397                 * We will only need *early* access to the following
398                 * two EFI runtime services before set_virtual_address_map
399                 * is invoked.
400                 */
401                efi_phys.get_time = (efi_get_time_t *)runtime->get_time;
402                efi_phys.set_virtual_address_map =
403                        (efi_set_virtual_address_map_t *)
404                        runtime->set_virtual_address_map;
405                /*
406                 * Make efi_get_time can be called before entering
407                 * virtual mode.
408                 */
409                efi.get_time = phys_efi_get_time;
410        } else
411                printk(KERN_ERR "Could not map the EFI runtime service "
412                       "table!\n");
413        early_iounmap(runtime, sizeof(efi_runtime_services_t));
414
415        /* Map the EFI memory map */
416        memmap.map = early_ioremap((unsigned long)memmap.phys_map,
417                                   memmap.nr_map * memmap.desc_size);
418        if (memmap.map == NULL)
419                printk(KERN_ERR "Could not map the EFI memory map!\n");
420        memmap.map_end = memmap.map + (memmap.nr_map * memmap.desc_size);
421
422        if (memmap.desc_size != sizeof(efi_memory_desc_t))
423                printk(KERN_WARNING
424                  "Kernel-defined memdesc doesn't match the one from EFI!\n");
425
426        if (add_efi_memmap)
427                do_add_efi_memmap();
428
429        /* Setup for EFI runtime service */
430        reboot_type = BOOT_EFI;
431
432#if EFI_DEBUG
433        print_efi_memmap();
434#endif
435}
436
437static void __init runtime_code_page_mkexec(void)
438{
439        efi_memory_desc_t *md;
440        void *p;
441        u64 addr, npages;
442
443        /* Make EFI runtime service code area executable */
444        for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
445                md = p;
446
447                if (md->type != EFI_RUNTIME_SERVICES_CODE)
448                        continue;
449
450                addr = md->virt_addr;
451                npages = md->num_pages;
452                memrange_efi_to_native(&addr, &npages);
453                set_memory_x(addr, npages);
454        }
455}
456
457/*
458 * This function will switch the EFI runtime services to virtual mode.
459 * Essentially, look through the EFI memmap and map every region that
460 * has the runtime attribute bit set in its memory descriptor and update
461 * that memory descriptor with the virtual address obtained from ioremap().
462 * This enables the runtime services to be called without having to
463 * thunk back into physical mode for every invocation.
464 */
465void __init efi_enter_virtual_mode(void)
466{
467        efi_memory_desc_t *md;
468        efi_status_t status;
469        unsigned long size;
470        u64 end, systab, addr, npages;
471        void *p, *va;
472
473        efi.systab = NULL;
474        for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
475                md = p;
476                if (!(md->attribute & EFI_MEMORY_RUNTIME))
477                        continue;
478
479                size = md->num_pages << EFI_PAGE_SHIFT;
480                end = md->phys_addr + size;
481
482                if (PFN_UP(end) <= max_low_pfn_mapped)
483                        va = __va(md->phys_addr);
484                else
485                        va = efi_ioremap(md->phys_addr, size);
486
487                md->virt_addr = (u64) (unsigned long) va;
488
489                if (!va) {
490                        printk(KERN_ERR PFX "ioremap of 0x%llX failed!\n",
491                               (unsigned long long)md->phys_addr);
492                        continue;
493                }
494
495                if (!(md->attribute & EFI_MEMORY_WB)) {
496                        addr = md->virt_addr;
497                        npages = md->num_pages;
498                        memrange_efi_to_native(&addr, &npages);
499                        set_memory_uc(addr, npages);
500                }
501
502                systab = (u64) (unsigned long) efi_phys.systab;
503                if (md->phys_addr <= systab && systab < end) {
504                        systab += md->virt_addr - md->phys_addr;
505                        efi.systab = (efi_system_table_t *) (unsigned long) systab;
506                }
507        }
508
509        BUG_ON(!efi.systab);
510
511        status = phys_efi_set_virtual_address_map(
512                memmap.desc_size * memmap.nr_map,
513                memmap.desc_size,
514                memmap.desc_version,
515                memmap.phys_map);
516
517        if (status != EFI_SUCCESS) {
518                printk(KERN_ALERT "Unable to switch EFI into virtual mode "
519                       "(status=%lx)!\n", status);
520                panic("EFI call to SetVirtualAddressMap() failed!");
521        }
522
523        /*
524         * Now that EFI is in virtual mode, update the function
525         * pointers in the runtime service table to the new virtual addresses.
526         *
527         * Call EFI services through wrapper functions.
528         */
529        efi.get_time = virt_efi_get_time;
530        efi.set_time = virt_efi_set_time;
531        efi.get_wakeup_time = virt_efi_get_wakeup_time;
532        efi.set_wakeup_time = virt_efi_set_wakeup_time;
533        efi.get_variable = virt_efi_get_variable;
534        efi.get_next_variable = virt_efi_get_next_variable;
535        efi.set_variable = virt_efi_set_variable;
536        efi.get_next_high_mono_count = virt_efi_get_next_high_mono_count;
537        efi.reset_system = virt_efi_reset_system;
538        efi.set_virtual_address_map = virt_efi_set_virtual_address_map;
539        if (__supported_pte_mask & _PAGE_NX)
540                runtime_code_page_mkexec();
541        early_iounmap(memmap.map, memmap.nr_map * memmap.desc_size);
542        memmap.map = NULL;
543}
544
545/*
546 * Convenience functions to obtain memory types and attributes
547 */
548u32 efi_mem_type(unsigned long phys_addr)
549{
550        efi_memory_desc_t *md;
551        void *p;
552
553        for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
554                md = p;
555                if ((md->phys_addr <= phys_addr) &&
556                    (phys_addr < (md->phys_addr +
557                                  (md->num_pages << EFI_PAGE_SHIFT))))
558                        return md->type;
559        }
560        return 0;
561}
562
563u64 efi_mem_attributes(unsigned long phys_addr)
564{
565        efi_memory_desc_t *md;
566        void *p;
567
568        for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
569                md = p;
570                if ((md->phys_addr <= phys_addr) &&
571                    (phys_addr < (md->phys_addr +
572                                  (md->num_pages << EFI_PAGE_SHIFT))))
573                        return md->attribute;
574        }
575        return 0;
576}