Root/target/linux/generic/patches-2.6.39/305-mips_module_reloc.patch

1--- a/arch/mips/Makefile
2+++ b/arch/mips/Makefile
3@@ -90,8 +90,8 @@ all-$(CONFIG_SYS_SUPPORTS_ZBOOT)+= vmlin
4 cflags-y += -G 0 -mno-abicalls -fno-pic -pipe
5 cflags-y += -msoft-float
6 LDFLAGS_vmlinux += -G 0 -static -n -nostdlib
7-KBUILD_AFLAGS_MODULE += -mlong-calls
8-KBUILD_CFLAGS_MODULE += -mlong-calls
9+KBUILD_AFLAGS_MODULE += -mno-long-calls
10+KBUILD_CFLAGS_MODULE += -mno-long-calls
11 
12 cflags-y += -ffreestanding
13 
14--- a/arch/mips/include/asm/module.h
15+++ b/arch/mips/include/asm/module.h
16@@ -9,6 +9,11 @@ struct mod_arch_specific {
17     struct list_head dbe_list;
18     const struct exception_table_entry *dbe_start;
19     const struct exception_table_entry *dbe_end;
20+
21+ void *phys_plt_tbl;
22+ void *virt_plt_tbl;
23+ unsigned int phys_plt_offset;
24+ unsigned int virt_plt_offset;
25 };
26 
27 typedef uint8_t Elf64_Byte; /* Type for a 8-bit quantity. */
28--- a/arch/mips/kernel/module.c
29+++ b/arch/mips/kernel/module.c
30@@ -45,6 +45,117 @@ static struct mips_hi16 *mips_hi16_list;
31 static LIST_HEAD(dbe_list);
32 static DEFINE_SPINLOCK(dbe_lock);
33 
34+/*
35+ * Get the potential max trampolines size required of the init and
36+ * non-init sections. Only used if we cannot find enough contiguous
37+ * physically mapped memory to put the module into.
38+ */
39+static unsigned int
40+get_plt_size(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
41+ const char *secstrings, unsigned int symindex, bool is_init)
42+{
43+ unsigned long ret = 0;
44+ unsigned int i, j;
45+ Elf_Sym *syms;
46+
47+ /* Everything marked ALLOC (this includes the exported symbols) */
48+ for (i = 1; i < hdr->e_shnum; ++i) {
49+ unsigned int info = sechdrs[i].sh_info;
50+
51+ if (sechdrs[i].sh_type != SHT_REL
52+ && sechdrs[i].sh_type != SHT_RELA)
53+ continue;
54+
55+ /* Not a valid relocation section? */
56+ if (info >= hdr->e_shnum)
57+ continue;
58+
59+ /* Don't bother with non-allocated sections */
60+ if (!(sechdrs[info].sh_flags & SHF_ALLOC))
61+ continue;
62+
63+ /* If it's called *.init*, and we're not init, we're
64+ not interested */
65+ if ((strstr(secstrings + sechdrs[i].sh_name, ".init") != 0)
66+ != is_init)
67+ continue;
68+
69+ syms = (Elf_Sym *) sechdrs[symindex].sh_addr;
70+ if (sechdrs[i].sh_type == SHT_REL) {
71+ Elf_Mips_Rel *rel = (void *) sechdrs[i].sh_addr;
72+ unsigned int size = sechdrs[i].sh_size / sizeof(*rel);
73+
74+ for (j = 0; j < size; ++j) {
75+ Elf_Sym *sym;
76+
77+ if (ELF_MIPS_R_TYPE(rel[j]) != R_MIPS_26)
78+ continue;
79+
80+ sym = syms + ELF_MIPS_R_SYM(rel[j]);
81+ if (!is_init && sym->st_shndx != SHN_UNDEF)
82+ continue;
83+
84+ ret += 4 * sizeof(int);
85+ }
86+ } else {
87+ Elf_Mips_Rela *rela = (void *) sechdrs[i].sh_addr;
88+ unsigned int size = sechdrs[i].sh_size / sizeof(*rela);
89+
90+ for (j = 0; j < size; ++j) {
91+ Elf_Sym *sym;
92+
93+ if (ELF_MIPS_R_TYPE(rela[j]) != R_MIPS_26)
94+ continue;
95+
96+ sym = syms + ELF_MIPS_R_SYM(rela[j]);
97+ if (!is_init && sym->st_shndx != SHN_UNDEF)
98+ continue;
99+
100+ ret += 4 * sizeof(int);
101+ }
102+ }
103+ }
104+
105+ return ret;
106+}
107+
108+#ifndef MODULE_START
109+static void *alloc_phys(unsigned long size)
110+{
111+ unsigned order;
112+ struct page *page;
113+ struct page *p;
114+
115+ size = PAGE_ALIGN(size);
116+ order = get_order(size);
117+
118+ page = alloc_pages(GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN |
119+ __GFP_THISNODE, order);
120+ if (!page)
121+ return NULL;
122+
123+ split_page(page, order);
124+
125+ for (p = page + (size >> PAGE_SHIFT); p < page + (1 << order); ++p)
126+ __free_page(p);
127+
128+ return page_address(page);
129+}
130+#endif
131+
132+static void free_phys(void *ptr, unsigned long size)
133+{
134+ struct page *page;
135+ struct page *end;
136+
137+ page = virt_to_page(ptr);
138+ end = page + (PAGE_ALIGN(size) >> PAGE_SHIFT);
139+
140+ for (; page < end; ++page)
141+ __free_page(page);
142+}
143+
144+
145 void *module_alloc(unsigned long size)
146 {
147 #ifdef MODULE_START
148@@ -52,21 +163,99 @@ void *module_alloc(unsigned long size)
149                 GFP_KERNEL, PAGE_KERNEL, -1,
150                 __builtin_return_address(0));
151 #else
152+ void *ptr;
153+
154     if (size == 0)
155         return NULL;
156- return vmalloc(size);
157+
158+ ptr = alloc_phys(size);
159+
160+ /* If we failed to allocate physically contiguous memory,
161+ * fall back to regular vmalloc. The module loader code will
162+ * create jump tables to handle long jumps */
163+ if (!ptr)
164+ return vmalloc(size);
165+
166+ return ptr;
167+#endif
168+}
169+
170+static inline bool is_phys_addr(void *ptr)
171+{
172+#ifdef CONFIG_64BIT
173+ return (KSEGX((unsigned long)ptr) == CKSEG0);
174+#else
175+ return (KSEGX(ptr) == KSEG0);
176 #endif
177 }
178 
179 /* Free memory returned from module_alloc */
180 void module_free(struct module *mod, void *module_region)
181 {
182- vfree(module_region);
183+ if (is_phys_addr(module_region)) {
184+ if (mod->module_init == module_region)
185+ free_phys(module_region, mod->init_size);
186+ else if (mod->module_core == module_region)
187+ free_phys(module_region, mod->core_size);
188+ else
189+ BUG();
190+ } else {
191+ vfree(module_region);
192+ }
193+}
194+
195+static void *__module_alloc(int size, bool phys)
196+{
197+ void *ptr;
198+
199+ if (phys)
200+ ptr = kmalloc(size, GFP_KERNEL);
201+ else
202+ ptr = vmalloc(size);
203+ return ptr;
204+}
205+
206+static void __module_free(void *ptr)
207+{
208+ if (is_phys_addr(ptr))
209+ kfree(ptr);
210+ else
211+ vfree(ptr);
212 }
213 
214 int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
215                   char *secstrings, struct module *mod)
216 {
217+ unsigned int symindex = 0;
218+ unsigned int core_size, init_size;
219+ int i;
220+
221+ for (i = 1; i < hdr->e_shnum; i++)
222+ if (sechdrs[i].sh_type == SHT_SYMTAB)
223+ symindex = i;
224+
225+ core_size = get_plt_size(hdr, sechdrs, secstrings, symindex, false);
226+ init_size = get_plt_size(hdr, sechdrs, secstrings, symindex, true);
227+
228+ mod->arch.phys_plt_offset = 0;
229+ mod->arch.virt_plt_offset = 0;
230+ mod->arch.phys_plt_tbl = NULL;
231+ mod->arch.virt_plt_tbl = NULL;
232+
233+ if ((core_size + init_size) == 0)
234+ return 0;
235+
236+ mod->arch.phys_plt_tbl = __module_alloc(core_size + init_size, 1);
237+ if (!mod->arch.phys_plt_tbl)
238+ return -ENOMEM;
239+
240+ mod->arch.virt_plt_tbl = __module_alloc(core_size + init_size, 0);
241+ if (!mod->arch.virt_plt_tbl) {
242+ __module_free(mod->arch.phys_plt_tbl);
243+ mod->arch.phys_plt_tbl = NULL;
244+ return -ENOMEM;
245+ }
246+
247     return 0;
248 }
249 
250@@ -89,28 +278,36 @@ static int apply_r_mips_32_rela(struct m
251     return 0;
252 }
253 
254-static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
255+static Elf_Addr add_plt_entry_to(unsigned *plt_offset,
256+ void *start, Elf_Addr v)
257 {
258- if (v % 4) {
259- pr_err("module %s: dangerous R_MIPS_26 REL relocation\n",
260- me->name);
261- return -ENOEXEC;
262- }
263+ unsigned *tramp = start + *plt_offset;
264+ *plt_offset += 4 * sizeof(int);
265 
266- if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
267- printk(KERN_ERR
268- "module %s: relocation overflow\n",
269- me->name);
270- return -ENOEXEC;
271- }
272+ /* adjust carry for addiu */
273+ if (v & 0x00008000)
274+ v += 0x10000;
275 
276- *location = (*location & ~0x03ffffff) |
277- ((*location + (v >> 2)) & 0x03ffffff);
278+ tramp[0] = 0x3c190000 | (v >> 16); /* lui t9, hi16 */
279+ tramp[1] = 0x27390000 | (v & 0xffff); /* addiu t9, t9, lo16 */
280+ tramp[2] = 0x03200008; /* jr t9 */
281+ tramp[3] = 0x00000000; /* nop */
282 
283- return 0;
284+ return (Elf_Addr) tramp;
285 }
286 
287-static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v)
288+static Elf_Addr add_plt_entry(struct module *me, void *location, Elf_Addr v)
289+{
290+ if (is_phys_addr(location))
291+ return add_plt_entry_to(&me->arch.phys_plt_offset,
292+ me->arch.phys_plt_tbl, v);
293+ else
294+ return add_plt_entry_to(&me->arch.virt_plt_offset,
295+ me->arch.virt_plt_tbl, v);
296+
297+}
298+
299+static int set_r_mips_26(struct module *me, u32 *location, u32 ofs, Elf_Addr v)
300 {
301     if (v % 4) {
302         pr_err("module %s: dangerous R_MIPS_26 RELArelocation\n",
303@@ -119,17 +316,31 @@ static int apply_r_mips_26_rela(struct m
304     }
305 
306     if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
307- printk(KERN_ERR
308+ v = add_plt_entry(me, location, v + (ofs << 2));
309+ if (!v) {
310+ printk(KERN_ERR
311                "module %s: relocation overflow\n",
312                me->name);
313- return -ENOEXEC;
314+ return -ENOEXEC;
315+ }
316+ ofs = 0;
317     }
318 
319- *location = (*location & ~0x03ffffff) | ((v >> 2) & 0x03ffffff);
320+ *location = (*location & ~0x03ffffff) | ((ofs + (v >> 2)) & 0x03ffffff);
321 
322     return 0;
323 }
324 
325+static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
326+{
327+ return set_r_mips_26(me, location, *location & 0x03ffffff, v);
328+}
329+
330+static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v)
331+{
332+ return set_r_mips_26(me, location, 0, v);
333+}
334+
335 static int apply_r_mips_hi16_rel(struct module *me, u32 *location, Elf_Addr v)
336 {
337     struct mips_hi16 *n;
338@@ -397,11 +608,32 @@ int module_finalize(const Elf_Ehdr *hdr,
339         list_add(&me->arch.dbe_list, &dbe_list);
340         spin_unlock_irq(&dbe_lock);
341     }
342+
343+ /* Get rid of the fixup trampoline if we're running the module
344+ * from physically mapped address space */
345+ if (me->arch.phys_plt_offset == 0) {
346+ __module_free(me->arch.phys_plt_tbl);
347+ me->arch.phys_plt_tbl = NULL;
348+ }
349+ if (me->arch.virt_plt_offset == 0) {
350+ __module_free(me->arch.virt_plt_tbl);
351+ me->arch.virt_plt_tbl = NULL;
352+ }
353+
354     return 0;
355 }
356 
357 void module_arch_cleanup(struct module *mod)
358 {
359+ if (mod->arch.phys_plt_tbl) {
360+ __module_free(mod->arch.phys_plt_tbl);
361+ mod->arch.phys_plt_tbl = NULL;
362+ }
363+ if (mod->arch.virt_plt_tbl) {
364+ __module_free(mod->arch.virt_plt_tbl);
365+ mod->arch.virt_plt_tbl = NULL;
366+ }
367+
368     spin_lock_irq(&dbe_lock);
369     list_del(&mod->arch.dbe_list);
370     spin_unlock_irq(&dbe_lock);
371

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