X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=arch%2Farm%2Fkernel%2Funwind.c;h=00df012c46784ac8c510466f1a4124158c3f86a3;hb=822a5d313197c059924d394e6851be3cb312caa7;hp=e7e8365795c3d3272a4ef56d34d41662acd608b8;hpb=45ff6fa1adf81f72e4815f0a993a644467b7b185;p=pandora-kernel.git diff --git a/arch/arm/kernel/unwind.c b/arch/arm/kernel/unwind.c index e7e8365795c3..00df012c4678 100644 --- a/arch/arm/kernel/unwind.c +++ b/arch/arm/kernel/unwind.c @@ -67,7 +67,7 @@ EXPORT_SYMBOL(__aeabi_unwind_cpp_pr2); struct unwind_ctrl_block { unsigned long vrs[16]; /* virtual register set */ - unsigned long *insn; /* pointer to the current instructions word */ + const unsigned long *insn; /* pointer to the current instructions word */ int entries; /* number of entries left to interpret */ int byte; /* current byte number in the instructions word */ }; @@ -83,8 +83,9 @@ enum regs { PC = 15 }; -extern struct unwind_idx __start_unwind_idx[]; -extern struct unwind_idx __stop_unwind_idx[]; +extern const struct unwind_idx __start_unwind_idx[]; +static const struct unwind_idx *__origin_unwind_idx; +extern const struct unwind_idx __stop_unwind_idx[]; static DEFINE_SPINLOCK(unwind_lock); static LIST_HEAD(unwind_tables); @@ -98,45 +99,99 @@ static LIST_HEAD(unwind_tables); }) /* - * Binary search in the unwind index. The entries entries are + * Binary search in the unwind index. The entries are * guaranteed to be sorted in ascending order by the linker. + * + * start = first entry + * origin = first entry with positive offset (or stop if there is no such entry) + * stop - 1 = last entry */ -static struct unwind_idx *search_index(unsigned long addr, - struct unwind_idx *first, - struct unwind_idx *last) +static const struct unwind_idx *search_index(unsigned long addr, + const struct unwind_idx *start, + const struct unwind_idx *origin, + const struct unwind_idx *stop) { - pr_debug("%s(%08lx, %p, %p)\n", __func__, addr, first, last); + unsigned long addr_prel31; + + pr_debug("%s(%08lx, %p, %p, %p)\n", + __func__, addr, start, origin, stop); + + /* + * only search in the section with the matching sign. This way the + * prel31 numbers can be compared as unsigned longs. + */ + if (addr < (unsigned long)start) + /* negative offsets: [start; origin) */ + stop = origin; + else + /* positive offsets: [origin; stop) */ + start = origin; + + /* prel31 for address relavive to start */ + addr_prel31 = (addr - (unsigned long)start) & 0x7fffffff; - if (addr < first->addr) { + while (start < stop - 1) { + const struct unwind_idx *mid = start + ((stop - start) >> 1); + + /* + * As addr_prel31 is relative to start an offset is needed to + * make it relative to mid. + */ + if (addr_prel31 - ((unsigned long)mid - (unsigned long)start) < + mid->addr_offset) + stop = mid; + else { + /* keep addr_prel31 relative to start */ + addr_prel31 -= ((unsigned long)mid - + (unsigned long)start); + start = mid; + } + } + + if (likely(start->addr_offset <= addr_prel31)) + return start; + else { pr_warning("unwind: Unknown symbol address %08lx\n", addr); return NULL; - } else if (addr >= last->addr) - return last; + } +} - while (first < last - 1) { - struct unwind_idx *mid = first + ((last - first + 1) >> 1); +static const struct unwind_idx *unwind_find_origin( + const struct unwind_idx *start, const struct unwind_idx *stop) +{ + pr_debug("%s(%p, %p)\n", __func__, start, stop); + while (start < stop) { + const struct unwind_idx *mid = start + ((stop - start) >> 1); - if (addr < mid->addr) - last = mid; + if (mid->addr_offset >= 0x40000000) + /* negative offset */ + start = mid + 1; else - first = mid; + /* positive offset */ + stop = mid; } - - return first; + pr_debug("%s -> %p\n", __func__, stop); + return stop; } -static struct unwind_idx *unwind_find_idx(unsigned long addr) +static const struct unwind_idx *unwind_find_idx(unsigned long addr) { - struct unwind_idx *idx = NULL; + const struct unwind_idx *idx = NULL; unsigned long flags; pr_debug("%s(%08lx)\n", __func__, addr); - if (core_kernel_text(addr)) + if (core_kernel_text(addr)) { + if (unlikely(!__origin_unwind_idx)) + __origin_unwind_idx = + unwind_find_origin(__start_unwind_idx, + __stop_unwind_idx); + /* main unwind table */ idx = search_index(addr, __start_unwind_idx, - __stop_unwind_idx - 1); - else { + __origin_unwind_idx, + __stop_unwind_idx); + } else { /* module unwind tables */ struct unwind_table *table; @@ -145,7 +200,8 @@ static struct unwind_idx *unwind_find_idx(unsigned long addr) if (addr >= table->begin_addr && addr < table->end_addr) { idx = search_index(addr, table->start, - table->stop - 1); + table->origin, + table->stop); /* Move-to-front to exploit common traces */ list_move(&table->list, &unwind_tables); break; @@ -274,7 +330,7 @@ static int unwind_exec_insn(struct unwind_ctrl_block *ctrl) int unwind_frame(struct stackframe *frame) { unsigned long high, low; - struct unwind_idx *idx; + const struct unwind_idx *idx; struct unwind_ctrl_block ctrl; /* only go to a higher address on the stack */ @@ -399,7 +455,6 @@ struct unwind_table *unwind_table_add(unsigned long start, unsigned long size, unsigned long text_size) { unsigned long flags; - struct unwind_idx *idx; struct unwind_table *tab = kmalloc(sizeof(*tab), GFP_KERNEL); pr_debug("%s(%08lx, %08lx, %08lx, %08lx)\n", __func__, start, size, @@ -408,15 +463,12 @@ struct unwind_table *unwind_table_add(unsigned long start, unsigned long size, if (!tab) return tab; - tab->start = (struct unwind_idx *)start; - tab->stop = (struct unwind_idx *)(start + size); + tab->start = (const struct unwind_idx *)start; + tab->stop = (const struct unwind_idx *)(start + size); + tab->origin = unwind_find_origin(tab->start, tab->stop); tab->begin_addr = text_addr; tab->end_addr = text_addr + text_size; - /* Convert the symbol addresses to absolute values */ - for (idx = tab->start; idx < tab->stop; idx++) - idx->addr = prel31_to_addr(&idx->addr); - spin_lock_irqsave(&unwind_lock, flags); list_add_tail(&tab->list, &unwind_tables); spin_unlock_irqrestore(&unwind_lock, flags); @@ -437,16 +489,3 @@ void unwind_table_del(struct unwind_table *tab) kfree(tab); } - -int __init unwind_init(void) -{ - struct unwind_idx *idx; - - /* Convert the symbol addresses to absolute values */ - for (idx = __start_unwind_idx; idx < __stop_unwind_idx; idx++) - idx->addr = prel31_to_addr(&idx->addr); - - pr_debug("unwind: ARM stack unwinding initialised\n"); - - return 0; -}