Root/target/linux/generic-2.6/patches-2.6.32/027-mips_module_reloc.patch

1--- a/arch/mips/Makefile
2+++ b/arch/mips/Makefile
3@@ -83,7 +83,7 @@ all-$(CONFIG_BOOT_ELF64) := $(vmlinux-64
4 cflags-y += -G 0 -mno-abicalls -fno-pic -pipe
5 cflags-y += -msoft-float
6 LDFLAGS_vmlinux += -G 0 -static -n -nostdlib
7-MODFLAGS += -mlong-calls
8+MODFLAGS += -mno-long-calls
9 
10 cflags-y += -ffreestanding
11 
12--- a/arch/mips/include/asm/module.h
13+++ b/arch/mips/include/asm/module.h
14@@ -9,6 +9,11 @@ struct mod_arch_specific {
15     struct list_head dbe_list;
16     const struct exception_table_entry *dbe_start;
17     const struct exception_table_entry *dbe_end;
18+
19+ void *phys_plt_tbl;
20+ void *virt_plt_tbl;
21+ unsigned int phys_plt_offset;
22+ unsigned int virt_plt_offset;
23 };
24 
25 typedef uint8_t Elf64_Byte; /* Type for a 8-bit quantity. */
26--- a/arch/mips/kernel/module.c
27+++ b/arch/mips/kernel/module.c
28@@ -43,6 +43,117 @@ static struct mips_hi16 *mips_hi16_list;
29 static LIST_HEAD(dbe_list);
30 static DEFINE_SPINLOCK(dbe_lock);
31 
32+/*
33+ * Get the potential max trampolines size required of the init and
34+ * non-init sections. Only used if we cannot find enough contiguous
35+ * physically mapped memory to put the module into.
36+ */
37+static unsigned int
38+get_plt_size(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
39+ const char *secstrings, unsigned int symindex, bool is_init)
40+{
41+ unsigned long ret = 0;
42+ unsigned int i, j;
43+ Elf_Sym *syms;
44+
45+ /* Everything marked ALLOC (this includes the exported symbols) */
46+ for (i = 1; i < hdr->e_shnum; ++i) {
47+ unsigned int info = sechdrs[i].sh_info;
48+
49+ if (sechdrs[i].sh_type != SHT_REL
50+ && sechdrs[i].sh_type != SHT_RELA)
51+ continue;
52+
53+ /* Not a valid relocation section? */
54+ if (info >= hdr->e_shnum)
55+ continue;
56+
57+ /* Don't bother with non-allocated sections */
58+ if (!(sechdrs[info].sh_flags & SHF_ALLOC))
59+ continue;
60+
61+ /* If it's called *.init*, and we're not init, we're
62+ not interested */
63+ if ((strstr(secstrings + sechdrs[i].sh_name, ".init") != 0)
64+ != is_init)
65+ continue;
66+
67+ syms = (Elf_Sym *) sechdrs[symindex].sh_addr;
68+ if (sechdrs[i].sh_type == SHT_REL) {
69+ Elf_Mips_Rel *rel = (void *) sechdrs[i].sh_addr;
70+ unsigned int size = sechdrs[i].sh_size / sizeof(*rel);
71+
72+ for (j = 0; j < size; ++j) {
73+ Elf_Sym *sym;
74+
75+ if (ELF_MIPS_R_TYPE(rel[j]) != R_MIPS_26)
76+ continue;
77+
78+ sym = syms + ELF_MIPS_R_SYM(rel[j]);
79+ if (!is_init && sym->st_shndx != SHN_UNDEF)
80+ continue;
81+
82+ ret += 4 * sizeof(int);
83+ }
84+ } else {
85+ Elf_Mips_Rela *rela = (void *) sechdrs[i].sh_addr;
86+ unsigned int size = sechdrs[i].sh_size / sizeof(*rela);
87+
88+ for (j = 0; j < size; ++j) {
89+ Elf_Sym *sym;
90+
91+ if (ELF_MIPS_R_TYPE(rela[j]) != R_MIPS_26)
92+ continue;
93+
94+ sym = syms + ELF_MIPS_R_SYM(rela[j]);
95+ if (!is_init && sym->st_shndx != SHN_UNDEF)
96+ continue;
97+
98+ ret += 4 * sizeof(int);
99+ }
100+ }
101+ }
102+
103+ return ret;
104+}
105+
106+#ifndef MODULE_START
107+static void *alloc_phys(unsigned long size)
108+{
109+ unsigned order;
110+ struct page *page;
111+ struct page *p;
112+
113+ size = PAGE_ALIGN(size);
114+ order = get_order(size);
115+
116+ page = alloc_pages(GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN |
117+ __GFP_THISNODE, order);
118+ if (!page)
119+ return NULL;
120+
121+ split_page(page, order);
122+
123+ for (p = page + (size >> PAGE_SHIFT); p < page + (1 << order); ++p)
124+ __free_page(p);
125+
126+ return page_address(page);
127+}
128+#endif
129+
130+static void free_phys(void *ptr, unsigned long size)
131+{
132+ struct page *page;
133+ struct page *end;
134+
135+ page = virt_to_page(ptr);
136+ end = page + (PAGE_ALIGN(size) >> PAGE_SHIFT);
137+
138+ for (; page < end; ++page)
139+ __free_page(page);
140+}
141+
142+
143 void *module_alloc(unsigned long size)
144 {
145 #ifdef MODULE_START
146@@ -58,21 +169,99 @@ void *module_alloc(unsigned long size)
147 
148     return __vmalloc_area(area, GFP_KERNEL, PAGE_KERNEL);
149 #else
150+ void *ptr;
151+
152     if (size == 0)
153         return NULL;
154- return vmalloc(size);
155+
156+ ptr = alloc_phys(size);
157+
158+ /* If we failed to allocate physically contiguous memory,
159+ * fall back to regular vmalloc. The module loader code will
160+ * create jump tables to handle long jumps */
161+ if (!ptr)
162+ return vmalloc(size);
163+
164+ return ptr;
165+#endif
166+}
167+
168+static inline bool is_phys_addr(void *ptr)
169+{
170+#ifdef CONFIG_64BIT
171+ return (KSEGX((unsigned long)ptr) == CKSEG0);
172+#else
173+ return (KSEGX(ptr) == KSEG0);
174 #endif
175 }
176 
177 /* Free memory returned from module_alloc */
178 void module_free(struct module *mod, void *module_region)
179 {
180- vfree(module_region);
181+ if (is_phys_addr(module_region)) {
182+ if (mod->module_init == module_region)
183+ free_phys(module_region, mod->init_size);
184+ else if (mod->module_core == module_region)
185+ free_phys(module_region, mod->core_size);
186+ else
187+ BUG();
188+ } else {
189+ vfree(module_region);
190+ }
191+}
192+
193+static void *__module_alloc(int size, bool phys)
194+{
195+ void *ptr;
196+
197+ if (phys)
198+ ptr = kmalloc(size, GFP_KERNEL);
199+ else
200+ ptr = vmalloc(size);
201+ return ptr;
202+}
203+
204+static void __module_free(void *ptr)
205+{
206+ if (is_phys_addr(ptr))
207+ kfree(ptr);
208+ else
209+ vfree(ptr);
210 }
211 
212 int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
213                   char *secstrings, struct module *mod)
214 {
215+ unsigned int symindex = 0;
216+ unsigned int core_size, init_size;
217+ int i;
218+
219+ for (i = 1; i < hdr->e_shnum; i++)
220+ if (sechdrs[i].sh_type == SHT_SYMTAB)
221+ symindex = i;
222+
223+ core_size = get_plt_size(hdr, sechdrs, secstrings, symindex, false);
224+ init_size = get_plt_size(hdr, sechdrs, secstrings, symindex, true);
225+
226+ mod->arch.phys_plt_offset = 0;
227+ mod->arch.virt_plt_offset = 0;
228+ mod->arch.phys_plt_tbl = NULL;
229+ mod->arch.virt_plt_tbl = NULL;
230+
231+ if ((core_size + init_size) == 0)
232+ return 0;
233+
234+ mod->arch.phys_plt_tbl = __module_alloc(core_size + init_size, 1);
235+ if (!mod->arch.phys_plt_tbl)
236+ return -ENOMEM;
237+
238+ mod->arch.virt_plt_tbl = __module_alloc(core_size + init_size, 0);
239+ if (!mod->arch.virt_plt_tbl) {
240+ __module_free(mod->arch.phys_plt_tbl);
241+ mod->arch.phys_plt_tbl = NULL;
242+ return -ENOMEM;
243+ }
244+
245     return 0;
246 }
247 
248@@ -95,28 +284,36 @@ static int apply_r_mips_32_rela(struct m
249     return 0;
250 }
251 
252-static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
253+static Elf_Addr add_plt_entry_to(unsigned *plt_offset,
254+ void *start, Elf_Addr v)
255 {
256- if (v % 4) {
257- pr_err("module %s: dangerous R_MIPS_26 REL relocation\n",
258- me->name);
259- return -ENOEXEC;
260- }
261+ unsigned *tramp = start + *plt_offset;
262+ *plt_offset += 4 * sizeof(int);
263 
264- if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
265- printk(KERN_ERR
266- "module %s: relocation overflow\n",
267- me->name);
268- return -ENOEXEC;
269- }
270+ /* adjust carry for addiu */
271+ if (v & 0x00008000)
272+ v += 0x10000;
273 
274- *location = (*location & ~0x03ffffff) |
275- ((*location + (v >> 2)) & 0x03ffffff);
276+ tramp[0] = 0x3c190000 | (v >> 16); /* lui t9, hi16 */
277+ tramp[1] = 0x27390000 | (v & 0xffff); /* addiu t9, t9, lo16 */
278+ tramp[2] = 0x03200008; /* jr t9 */
279+ tramp[3] = 0x00000000; /* nop */
280 
281- return 0;
282+ return (Elf_Addr) tramp;
283 }
284 
285-static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v)
286+static Elf_Addr add_plt_entry(struct module *me, void *location, Elf_Addr v)
287+{
288+ if (is_phys_addr(location))
289+ return add_plt_entry_to(&me->arch.phys_plt_offset,
290+ me->arch.phys_plt_tbl, v);
291+ else
292+ return add_plt_entry_to(&me->arch.virt_plt_offset,
293+ me->arch.virt_plt_tbl, v);
294+
295+}
296+
297+static int set_r_mips_26(struct module *me, u32 *location, u32 ofs, Elf_Addr v)
298 {
299     if (v % 4) {
300         pr_err("module %s: dangerous R_MIPS_26 RELArelocation\n",
301@@ -125,17 +322,31 @@ static int apply_r_mips_26_rela(struct m
302     }
303 
304     if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
305- printk(KERN_ERR
306+ v = add_plt_entry(me, location, v + (ofs << 2));
307+ if (!v) {
308+ printk(KERN_ERR
309                "module %s: relocation overflow\n",
310                me->name);
311- return -ENOEXEC;
312+ return -ENOEXEC;
313+ }
314+ ofs = 0;
315     }
316 
317- *location = (*location & ~0x03ffffff) | ((v >> 2) & 0x03ffffff);
318+ *location = (*location & ~0x03ffffff) | ((ofs + (v >> 2)) & 0x03ffffff);
319 
320     return 0;
321 }
322 
323+static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
324+{
325+ return set_r_mips_26(me, location, *location & 0x03ffffff, v);
326+}
327+
328+static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v)
329+{
330+ return set_r_mips_26(me, location, 0, v);
331+}
332+
333 static int apply_r_mips_hi16_rel(struct module *me, u32 *location, Elf_Addr v)
334 {
335     struct mips_hi16 *n;
336@@ -400,11 +611,32 @@ int module_finalize(const Elf_Ehdr *hdr,
337         list_add(&me->arch.dbe_list, &dbe_list);
338         spin_unlock_irq(&dbe_lock);
339     }
340+
341+ /* Get rid of the fixup trampoline if we're running the module
342+ * from physically mapped address space */
343+ if (me->arch.phys_plt_offset == 0) {
344+ __module_free(me->arch.phys_plt_tbl);
345+ me->arch.phys_plt_tbl = NULL;
346+ }
347+ if (me->arch.virt_plt_offset == 0) {
348+ __module_free(me->arch.virt_plt_tbl);
349+ me->arch.virt_plt_tbl = NULL;
350+ }
351+
352     return 0;
353 }
354 
355 void module_arch_cleanup(struct module *mod)
356 {
357+ if (mod->arch.phys_plt_tbl) {
358+ __module_free(mod->arch.phys_plt_tbl);
359+ mod->arch.phys_plt_tbl = NULL;
360+ }
361+ if (mod->arch.virt_plt_tbl) {
362+ __module_free(mod->arch.virt_plt_tbl);
363+ mod->arch.virt_plt_tbl = NULL;
364+ }
365+
366     spin_lock_irq(&dbe_lock);
367     list_del(&mod->arch.dbe_list);
368     spin_unlock_irq(&dbe_lock);
369

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