Root/target/linux/generic/patches-3.6/305-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@@ -11,6 +11,11 @@ struct mod_arch_specific {
17     const struct exception_table_entry *dbe_start;
18     const struct exception_table_entry *dbe_end;
19     struct mips_hi16 *r_mips_hi16_list;
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@@ -42,14 +42,219 @@ struct mips_hi16 {
31 static LIST_HEAD(dbe_list);
32 static DEFINE_SPINLOCK(dbe_lock);
33 
34-#ifdef MODULE_START
35+/*
36+ * Get the potential max trampolines size required of the init and
37+ * non-init sections. Only used if we cannot find enough contiguous
38+ * physically mapped memory to put the module into.
39+ */
40+static unsigned int
41+get_plt_size(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
42+ const char *secstrings, unsigned int symindex, bool is_init)
43+{
44+ unsigned long ret = 0;
45+ unsigned int i, j;
46+ Elf_Sym *syms;
47+
48+ /* Everything marked ALLOC (this includes the exported symbols) */
49+ for (i = 1; i < hdr->e_shnum; ++i) {
50+ unsigned int info = sechdrs[i].sh_info;
51+
52+ if (sechdrs[i].sh_type != SHT_REL
53+ && sechdrs[i].sh_type != SHT_RELA)
54+ continue;
55+
56+ /* Not a valid relocation section? */
57+ if (info >= hdr->e_shnum)
58+ continue;
59+
60+ /* Don't bother with non-allocated sections */
61+ if (!(sechdrs[info].sh_flags & SHF_ALLOC))
62+ continue;
63+
64+ /* If it's called *.init*, and we're not init, we're
65+ not interested */
66+ if ((strstr(secstrings + sechdrs[i].sh_name, ".init") != 0)
67+ != is_init)
68+ continue;
69+
70+ syms = (Elf_Sym *) sechdrs[symindex].sh_addr;
71+ if (sechdrs[i].sh_type == SHT_REL) {
72+ Elf_Mips_Rel *rel = (void *) sechdrs[i].sh_addr;
73+ unsigned int size = sechdrs[i].sh_size / sizeof(*rel);
74+
75+ for (j = 0; j < size; ++j) {
76+ Elf_Sym *sym;
77+
78+ if (ELF_MIPS_R_TYPE(rel[j]) != R_MIPS_26)
79+ continue;
80+
81+ sym = syms + ELF_MIPS_R_SYM(rel[j]);
82+ if (!is_init && sym->st_shndx != SHN_UNDEF)
83+ continue;
84+
85+ ret += 4 * sizeof(int);
86+ }
87+ } else {
88+ Elf_Mips_Rela *rela = (void *) sechdrs[i].sh_addr;
89+ unsigned int size = sechdrs[i].sh_size / sizeof(*rela);
90+
91+ for (j = 0; j < size; ++j) {
92+ Elf_Sym *sym;
93+
94+ if (ELF_MIPS_R_TYPE(rela[j]) != R_MIPS_26)
95+ continue;
96+
97+ sym = syms + ELF_MIPS_R_SYM(rela[j]);
98+ if (!is_init && sym->st_shndx != SHN_UNDEF)
99+ continue;
100+
101+ ret += 4 * sizeof(int);
102+ }
103+ }
104+ }
105+
106+ return ret;
107+}
108+
109+#ifndef MODULE_START
110+static void *alloc_phys(unsigned long size)
111+{
112+ unsigned order;
113+ struct page *page;
114+ struct page *p;
115+
116+ size = PAGE_ALIGN(size);
117+ order = get_order(size);
118+
119+ page = alloc_pages(GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN |
120+ __GFP_THISNODE, order);
121+ if (!page)
122+ return NULL;
123+
124+ split_page(page, order);
125+
126+ for (p = page + (size >> PAGE_SHIFT); p < page + (1 << order); ++p)
127+ __free_page(p);
128+
129+ return page_address(page);
130+}
131+#endif
132+
133+static void free_phys(void *ptr, unsigned long size)
134+{
135+ struct page *page;
136+ struct page *end;
137+
138+ page = virt_to_page(ptr);
139+ end = page + (PAGE_ALIGN(size) >> PAGE_SHIFT);
140+
141+ for (; page < end; ++page)
142+ __free_page(page);
143+}
144+
145+
146 void *module_alloc(unsigned long size)
147 {
148+#ifdef MODULE_START
149     return __vmalloc_node_range(size, 1, MODULE_START, MODULE_END,
150                 GFP_KERNEL, PAGE_KERNEL, -1,
151                 __builtin_return_address(0));
152+#else
153+ void *ptr;
154+
155+ if (size == 0)
156+ return NULL;
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+ if (is_phys_addr(module_region)) {
183+ if (mod->module_init == module_region)
184+ free_phys(module_region, mod->init_size);
185+ else if (mod->module_core == module_region)
186+ free_phys(module_region, mod->core_size);
187+ else
188+ BUG();
189+ } else {
190+ vfree(module_region);
191+ }
192+}
193+
194+static void *__module_alloc(int size, bool phys)
195+{
196+ void *ptr;
197+
198+ if (phys)
199+ ptr = kmalloc(size, GFP_KERNEL);
200+ else
201+ ptr = vmalloc(size);
202+ return ptr;
203+}
204+
205+static void __module_free(void *ptr)
206+{
207+ if (is_phys_addr(ptr))
208+ kfree(ptr);
209+ else
210+ vfree(ptr);
211+}
212+
213+int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
214+ char *secstrings, struct module *mod)
215+{
216+ unsigned int symindex = 0;
217+ unsigned int core_size, init_size;
218+ int i;
219+
220+ for (i = 1; i < hdr->e_shnum; i++)
221+ if (sechdrs[i].sh_type == SHT_SYMTAB)
222+ symindex = i;
223+
224+ core_size = get_plt_size(hdr, sechdrs, secstrings, symindex, false);
225+ init_size = get_plt_size(hdr, sechdrs, secstrings, symindex, true);
226+
227+ mod->arch.phys_plt_offset = 0;
228+ mod->arch.virt_plt_offset = 0;
229+ mod->arch.phys_plt_tbl = NULL;
230+ mod->arch.virt_plt_tbl = NULL;
231+
232+ if ((core_size + init_size) == 0)
233+ return 0;
234+
235+ mod->arch.phys_plt_tbl = __module_alloc(core_size + init_size, 1);
236+ if (!mod->arch.phys_plt_tbl)
237+ return -ENOMEM;
238+
239+ mod->arch.virt_plt_tbl = __module_alloc(core_size + init_size, 0);
240+ if (!mod->arch.virt_plt_tbl) {
241+ __module_free(mod->arch.phys_plt_tbl);
242+ mod->arch.phys_plt_tbl = NULL;
243+ return -ENOMEM;
244+ }
245+
246+ return 0;
247+}
248 
249 static int apply_r_mips_none(struct module *me, u32 *location, Elf_Addr v)
250 {
251@@ -70,28 +275,36 @@ static int apply_r_mips_32_rela(struct m
252     return 0;
253 }
254 
255-static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
256+static Elf_Addr add_plt_entry_to(unsigned *plt_offset,
257+ void *start, Elf_Addr v)
258 {
259- if (v % 4) {
260- pr_err("module %s: dangerous R_MIPS_26 REL relocation\n",
261- me->name);
262- return -ENOEXEC;
263- }
264+ unsigned *tramp = start + *plt_offset;
265+ *plt_offset += 4 * sizeof(int);
266 
267- if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
268- printk(KERN_ERR
269- "module %s: relocation overflow\n",
270- me->name);
271- return -ENOEXEC;
272- }
273+ /* adjust carry for addiu */
274+ if (v & 0x00008000)
275+ v += 0x10000;
276 
277- *location = (*location & ~0x03ffffff) |
278- ((*location + (v >> 2)) & 0x03ffffff);
279+ tramp[0] = 0x3c190000 | (v >> 16); /* lui t9, hi16 */
280+ tramp[1] = 0x27390000 | (v & 0xffff); /* addiu t9, t9, lo16 */
281+ tramp[2] = 0x03200008; /* jr t9 */
282+ tramp[3] = 0x00000000; /* nop */
283 
284- return 0;
285+ return (Elf_Addr) tramp;
286 }
287 
288-static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v)
289+static Elf_Addr add_plt_entry(struct module *me, void *location, Elf_Addr v)
290+{
291+ if (is_phys_addr(location))
292+ return add_plt_entry_to(&me->arch.phys_plt_offset,
293+ me->arch.phys_plt_tbl, v);
294+ else
295+ return add_plt_entry_to(&me->arch.virt_plt_offset,
296+ me->arch.virt_plt_tbl, v);
297+
298+}
299+
300+static int set_r_mips_26(struct module *me, u32 *location, u32 ofs, Elf_Addr v)
301 {
302     if (v % 4) {
303         pr_err("module %s: dangerous R_MIPS_26 RELArelocation\n",
304@@ -100,17 +313,31 @@ static int apply_r_mips_26_rela(struct m
305     }
306 
307     if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
308- printk(KERN_ERR
309+ v = add_plt_entry(me, location, v + (ofs << 2));
310+ if (!v) {
311+ printk(KERN_ERR
312                "module %s: relocation overflow\n",
313                me->name);
314- return -ENOEXEC;
315+ return -ENOEXEC;
316+ }
317+ ofs = 0;
318     }
319 
320- *location = (*location & ~0x03ffffff) | ((v >> 2) & 0x03ffffff);
321+ *location = (*location & ~0x03ffffff) | ((ofs + (v >> 2)) & 0x03ffffff);
322 
323     return 0;
324 }
325 
326+static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
327+{
328+ return set_r_mips_26(me, location, *location & 0x03ffffff, v);
329+}
330+
331+static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v)
332+{
333+ return set_r_mips_26(me, location, 0, v);
334+}
335+
336 static int apply_r_mips_hi16_rel(struct module *me, u32 *location, Elf_Addr v)
337 {
338     struct mips_hi16 *n;
339@@ -405,11 +632,32 @@ int module_finalize(const Elf_Ehdr *hdr,
340         list_add(&me->arch.dbe_list, &dbe_list);
341         spin_unlock_irq(&dbe_lock);
342     }
343+
344+ /* Get rid of the fixup trampoline if we're running the module
345+ * from physically mapped address space */
346+ if (me->arch.phys_plt_offset == 0) {
347+ __module_free(me->arch.phys_plt_tbl);
348+ me->arch.phys_plt_tbl = NULL;
349+ }
350+ if (me->arch.virt_plt_offset == 0) {
351+ __module_free(me->arch.virt_plt_tbl);
352+ me->arch.virt_plt_tbl = NULL;
353+ }
354+
355     return 0;
356 }
357 
358 void module_arch_cleanup(struct module *mod)
359 {
360+ if (mod->arch.phys_plt_tbl) {
361+ __module_free(mod->arch.phys_plt_tbl);
362+ mod->arch.phys_plt_tbl = NULL;
363+ }
364+ if (mod->arch.virt_plt_tbl) {
365+ __module_free(mod->arch.virt_plt_tbl);
366+ mod->arch.virt_plt_tbl = NULL;
367+ }
368+
369     spin_lock_irq(&dbe_lock);
370     list_del(&mod->arch.dbe_list);
371     spin_unlock_irq(&dbe_lock);
372

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