diff options
Diffstat (limited to 'arch/arm/lib32/unwind.c')
-rw-r--r-- | arch/arm/lib32/unwind.c | 138 |
1 files changed, 92 insertions, 46 deletions
diff --git a/arch/arm/lib32/unwind.c b/arch/arm/lib32/unwind.c index 02fae3c253..c355bba1b7 100644 --- a/arch/arm/lib32/unwind.c +++ b/arch/arm/lib32/unwind.c @@ -1,3 +1,5 @@ +// SPDX-License-Identifier: GPL-2.0-only + #include <common.h> #include <init.h> #include <asm/stacktrace.h> @@ -26,7 +28,7 @@ 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 */ }; @@ -40,8 +42,9 @@ enum regs { #define THREAD_SIZE 8192 -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[]; /* Convert a prel31 symbol to an absolute address */ #define prel31_to_addr(ptr) \ @@ -62,51 +65,106 @@ static void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long frame) { #ifdef CONFIG_KALLSYMS - pr_warning("[<%08lx>] (%pS) from [<%08lx>] (%pS)\n", where, (void *)where, from, (void *)from); + eprintf("[<%08lx>] (%pS) from [<%08lx>] (%pS)\n", where, (void *)where, from, (void *)from); #else - pr_warning("Function entered at [<%08lx>] from [<%08lx>]\n", where, from); + eprintf("Function entered at [<%08lx>] from [<%08lx>]\n", where, from); #endif } /* - * 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; + + 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 (addr < first->addr) { - pr_warning("unwind: Unknown symbol address %08lx\n", addr); + if (likely(start->addr_offset <= addr_prel31)) + return start; + else { + eprintf("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 - 1) { + const struct unwind_idx *mid = start + ((stop - start) >> 1); - if (addr < mid->addr) - last = mid; + if (mid->addr_offset >= 0x40000000) + /* negative offset */ + start = mid; 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; pr_debug("%s(%08lx)\n", __func__, addr); - if (is_kernel_text(addr)) + if (is_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 unwinding not supported */ } @@ -119,7 +177,7 @@ static unsigned long unwind_get_byte(struct unwind_ctrl_block *ctrl) unsigned long ret; if (ctrl->entries <= 0) { - pr_warning("unwind: Corrupt unwind table\n"); + eprintf("unwind: Corrupt unwind table\n"); return 0; } @@ -156,7 +214,7 @@ static int unwind_exec_insn(struct unwind_ctrl_block *ctrl) insn = (insn << 8) | unwind_get_byte(ctrl); mask = insn & 0x0fff; if (mask == 0) { - pr_warning("unwind: 'Refuse to unwind' instruction %04lx\n", + eprintf("unwind: 'Refuse to unwind' instruction %04lx\n", insn); return -URC_FAILURE; } @@ -195,7 +253,7 @@ static int unwind_exec_insn(struct unwind_ctrl_block *ctrl) int reg = 0; if (mask == 0 || mask & 0xf0) { - pr_warning("unwind: Spare encoding %04lx\n", + eprintf("unwind: Spare encoding %04lx\n", (insn << 8) | mask); return -URC_FAILURE; } @@ -213,7 +271,7 @@ static int unwind_exec_insn(struct unwind_ctrl_block *ctrl) ctrl->vrs[SP] += 0x204 + (uleb128 << 2); } else { - pr_warning("unwind: Unhandled instruction %02lx\n", insn); + eprintf("unwind: Unhandled instruction %02lx\n", insn); return -URC_FAILURE; } @@ -230,7 +288,7 @@ 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 */ @@ -245,7 +303,7 @@ int unwind_frame(struct stackframe *frame) idx = unwind_find_idx(frame->pc); if (!idx) { - pr_warning("unwind: Index not found %08lx\n", frame->pc); + eprintf("unwind: Index not found %08lx\n", frame->pc); return -URC_FAILURE; } @@ -264,7 +322,7 @@ int unwind_frame(struct stackframe *frame) /* only personality routine 0 supported in the index */ ctrl.insn = &idx->insn; else { - pr_warning("unwind: Unsupported personality routine %08lx in the index at %p\n", + eprintf("unwind: Unsupported personality routine %08lx in the index at %p\n", idx->insn, idx); return -URC_FAILURE; } @@ -277,7 +335,7 @@ int unwind_frame(struct stackframe *frame) ctrl.byte = 1; ctrl.entries = 1 + ((*ctrl.insn & 0x00ff0000) >> 16); } else { - pr_warning("unwind: Unsupported personality routine %08lx at %p\n", + eprintf("unwind: Unsupported personality routine %08lx at %p\n", *ctrl.insn, ctrl.insn); return -URC_FAILURE; } @@ -340,15 +398,3 @@ void dump_stack(void) { unwind_backtrace(NULL); } - -static int 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); - - return 0; -} -core_initcall(unwind_init); |