Root/target/linux/generic-2.6/patches-2.6.30/027-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 +43,116 @@ 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 void *module_alloc(unsigned long size)
143 {
144 #ifdef MODULE_START
145@@ -58,23 +168,101 @@ void *module_alloc(unsigned long size)
146 
147     return __vmalloc_area(area, GFP_KERNEL, PAGE_KERNEL);
148 #else
149+ void *ptr;
150+
151     if (size == 0)
152         return NULL;
153- return vmalloc(size);
154+
155+ ptr = alloc_phys(size);
156+
157+ /* If we failed to allocate physically contiguous memory,
158+ * fall back to regular vmalloc. The module loader code will
159+ * create jump tables to handle long jumps */
160+ if (!ptr)
161+ return vmalloc(size);
162+
163+ return ptr;
164+#endif
165+}
166+
167+static inline bool is_phys_addr(void *ptr)
168+{
169+#ifdef CONFIG_64BIT
170+ return (KSEGX((unsigned long)ptr) == CKSEG0);
171+#else
172+ return (KSEGX(ptr) == KSEG0);
173 #endif
174 }
175 
176 /* Free memory returned from module_alloc */
177 void module_free(struct module *mod, void *module_region)
178 {
179- vfree(module_region);
180+ if (is_phys_addr(module_region)) {
181+ if (mod->module_init == module_region)
182+ free_phys(module_region, mod->init_size);
183+ else if (mod->module_core == module_region)
184+ free_phys(module_region, mod->core_size);
185+ else
186+ BUG();
187+ } else {
188+ vfree(module_region);
189+ }
190     /* FIXME: If module_region == mod->init_region, trim exception
191            table entries. */
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@@ -97,27 +285,37 @@ static int apply_r_mips_32_rela(struct m
250     return 0;
251 }
252 
253-static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
254+static Elf_Addr add_plt_entry_to(unsigned *plt_offset,
255+ void *start, Elf_Addr v)
256 {
257- if (v % 4) {
258- printk(KERN_ERR "module %s: dangerous relocation\n", me->name);
259- return -ENOEXEC;
260- }
261+ unsigned *tramp = start + *plt_offset;
262 
263- if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
264- printk(KERN_ERR
265- "module %s: relocation overflow\n",
266- me->name);
267- return -ENOEXEC;
268- }
269+ *plt_offset += 4 * sizeof(int);
270 
271- *location = (*location & ~0x03ffffff) |
272- ((*location + (v >> 2)) & 0x03ffffff);
273+ /* adjust carry for addiu */
274+ if (v & 0x00008000)
275+ v += 0x10000;
276 
277- return 0;
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 (Elf_Addr) tramp;
284 }
285 
286-static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v)
287+static Elf_Addr add_plt_entry(struct module *me, void *location, Elf_Addr v)
288+{
289+ if (is_phys_addr(location))
290+ return add_plt_entry_to(&me->arch.phys_plt_offset,
291+ me->arch.phys_plt_tbl, v);
292+ else
293+ return add_plt_entry_to(&me->arch.virt_plt_offset,
294+ me->arch.virt_plt_tbl, v);
295+
296+}
297+
298+static int set_r_mips_26(struct module *me, u32 *location, u32 ofs, Elf_Addr v)
299 {
300     if (v % 4) {
301         printk(KERN_ERR "module %s: dangerous relocation\n", me->name);
302@@ -125,17 +323,31 @@ static int apply_r_mips_26_rela(struct m
303     }
304 
305     if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
306- printk(KERN_ERR
307+ v = add_plt_entry(me, location, v + (ofs << 2));
308+ if (!v) {
309+ printk(KERN_ERR
310                "module %s: relocation overflow\n",
311                me->name);
312- return -ENOEXEC;
313+ return -ENOEXEC;
314+ }
315+ ofs = 0;
316     }
317 
318- *location = (*location & ~0x03ffffff) | ((v >> 2) & 0x03ffffff);
319+ *location = (*location & ~0x03ffffff) | ((ofs + (v >> 2)) & 0x03ffffff);
320 
321     return 0;
322 }
323 
324+static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
325+{
326+ return set_r_mips_26(me, location, *location & 0x03ffffff, v);
327+}
328+
329+static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v)
330+{
331+ return set_r_mips_26(me, location, 0, v);
332+}
333+
334 static int apply_r_mips_hi16_rel(struct module *me, u32 *location, Elf_Addr v)
335 {
336     struct mips_hi16 *n;
337@@ -400,11 +612,32 @@ int module_finalize(const Elf_Ehdr *hdr,
338         list_add(&me->arch.dbe_list, &dbe_list);
339         spin_unlock_irq(&dbe_lock);
340     }
341+
342+ /* Get rid of the fixup trampoline if we're running the module
343+ * from physically mapped address space */
344+ if (me->arch.phys_plt_offset == 0) {
345+ __module_free(me->arch.phys_plt_tbl);
346+ me->arch.phys_plt_tbl = NULL;
347+ }
348+ if (me->arch.virt_plt_offset == 0) {
349+ __module_free(me->arch.virt_plt_tbl);
350+ me->arch.virt_plt_tbl = NULL;
351+ }
352+
353     return 0;
354 }
355 
356 void module_arch_cleanup(struct module *mod)
357 {
358+ if (mod->arch.phys_plt_tbl) {
359+ __module_free(mod->arch.phys_plt_tbl);
360+ mod->arch.phys_plt_tbl = NULL;
361+ }
362+ if (mod->arch.virt_plt_tbl) {
363+ __module_free(mod->arch.virt_plt_tbl);
364+ mod->arch.virt_plt_tbl = NULL;
365+ }
366+
367     spin_lock_irq(&dbe_lock);
368     list_del(&mod->arch.dbe_list);
369     spin_unlock_irq(&dbe_lock);
370

Archive Download this file

Branches:
backfire
history
master
release_2010-11-17
release_2010-12-14
release_2011-02-23
release_2011-05-28
release_2011-08-27
release_2011-11-13
release_2012-03-18
release_2012-04-09
release_2012-10-11
uclibc_nptl



interactive