[PATCH] CPEI gets warning at kernel/irq/migration.c:27/move_masked_irq()
[pandora-kernel.git] / kernel / unwind.c
index f69c804..09c2613 100644 (file)
 
 #include <linux/unwind.h>
 #include <linux/module.h>
-#include <linux/delay.h>
+#include <linux/bootmem.h>
+#include <linux/sort.h>
 #include <linux/stop_machine.h>
+#include <linux/uaccess.h>
 #include <asm/sections.h>
 #include <asm/uaccess.h>
 #include <asm/unaligned.h>
 
-extern char __start_unwind[], __end_unwind[];
+extern const char __start_unwind[], __end_unwind[];
+extern const u8 __start_unwind_hdr[], __end_unwind_hdr[];
 
 #define MAX_STACK_DEPTH 8
 
@@ -92,6 +95,7 @@ static const struct {
 
 typedef unsigned long uleb128_t;
 typedef   signed long sleb128_t;
+#define sleb128abs __builtin_labs
 
 static struct unwind_table {
        struct {
@@ -100,9 +104,11 @@ static struct unwind_table {
        } core, init;
        const void *address;
        unsigned long size;
+       const unsigned char *header;
+       unsigned long hdrsz;
        struct unwind_table *link;
        const char *name;
-} root_table, *last_table;
+} root_table;
 
 struct unwind_item {
        enum item_location {
@@ -131,6 +137,17 @@ struct unwind_state {
 
 static const struct cfa badCFA = { ARRAY_SIZE(reg_info), 1 };
 
+static unsigned unwind_debug;
+static int __init unwind_debug_setup(char *s)
+{
+       unwind_debug = simple_strtoul(s, NULL, 0);
+       return 1;
+}
+__setup("unwind_debug=", unwind_debug_setup);
+#define dprintk(lvl, fmt, args...) \
+       ((void)(lvl > unwind_debug \
+        || printk(KERN_DEBUG "unwind: " fmt "\n", ##args)))
+
 static struct unwind_table *find_table(unsigned long pc)
 {
        struct unwind_table *table;
@@ -145,6 +162,12 @@ static struct unwind_table *find_table(unsigned long pc)
        return table;
 }
 
+static unsigned long read_pointer(const u8 **pLoc,
+                                  const void *end,
+                                  signed ptrType,
+                                  unsigned long text_base,
+                                  unsigned long data_base);
+
 static void init_unwind_table(struct unwind_table *table,
                               const char *name,
                               const void *core_start,
@@ -152,14 +175,33 @@ static void init_unwind_table(struct unwind_table *table,
                               const void *init_start,
                               unsigned long init_size,
                               const void *table_start,
-                              unsigned long table_size)
+                              unsigned long table_size,
+                              const u8 *header_start,
+                              unsigned long header_size)
 {
+       const u8 *ptr = header_start + 4;
+       const u8 *end = header_start + header_size;
+
        table->core.pc = (unsigned long)core_start;
        table->core.range = core_size;
        table->init.pc = (unsigned long)init_start;
        table->init.range = init_size;
        table->address = table_start;
        table->size = table_size;
+       /* See if the linker provided table looks valid. */
+       if (header_size <= 4
+           || header_start[0] != 1
+           || (void *)read_pointer(&ptr, end, header_start[1], 0, 0)
+              != table_start
+           || !read_pointer(&ptr, end, header_start[2], 0, 0)
+           || !read_pointer(&ptr, end, header_start[3], 0,
+                            (unsigned long)header_start)
+           || !read_pointer(&ptr, end, header_start[3], 0,
+                            (unsigned long)header_start))
+               header_start = NULL;
+       table->hdrsz = header_size;
+       smp_wmb();
+       table->header = header_start;
        table->link = NULL;
        table->name = name;
 }
@@ -169,11 +211,150 @@ void __init unwind_init(void)
        init_unwind_table(&root_table, "kernel",
                          _text, _end - _text,
                          NULL, 0,
-                         __start_unwind, __end_unwind - __start_unwind);
+                         __start_unwind, __end_unwind - __start_unwind,
+                         __start_unwind_hdr, __end_unwind_hdr - __start_unwind_hdr);
+}
+
+static const u32 bad_cie, not_fde;
+static const u32 *cie_for_fde(const u32 *fde, const struct unwind_table *);
+static signed fde_pointer_type(const u32 *cie);
+
+struct eh_frame_hdr_table_entry {
+       unsigned long start, fde;
+};
+
+static int cmp_eh_frame_hdr_table_entries(const void *p1, const void *p2)
+{
+       const struct eh_frame_hdr_table_entry *e1 = p1;
+       const struct eh_frame_hdr_table_entry *e2 = p2;
+
+       return (e1->start > e2->start) - (e1->start < e2->start);
+}
+
+static void swap_eh_frame_hdr_table_entries(void *p1, void *p2, int size)
+{
+       struct eh_frame_hdr_table_entry *e1 = p1;
+       struct eh_frame_hdr_table_entry *e2 = p2;
+       unsigned long v;
+
+       v = e1->start;
+       e1->start = e2->start;
+       e2->start = v;
+       v = e1->fde;
+       e1->fde = e2->fde;
+       e2->fde = v;
+}
+
+static void __init setup_unwind_table(struct unwind_table *table,
+                                       void *(*alloc)(unsigned long))
+{
+       const u8 *ptr;
+       unsigned long tableSize = table->size, hdrSize;
+       unsigned n;
+       const u32 *fde;
+       struct {
+               u8 version;
+               u8 eh_frame_ptr_enc;
+               u8 fde_count_enc;
+               u8 table_enc;
+               unsigned long eh_frame_ptr;
+               unsigned int fde_count;
+               struct eh_frame_hdr_table_entry table[];
+       } __attribute__((__packed__)) *header;
+
+       if (table->header)
+               return;
+
+       if (table->hdrsz)
+               printk(KERN_WARNING ".eh_frame_hdr for '%s' present but unusable\n",
+                      table->name);
+
+       if (tableSize & (sizeof(*fde) - 1))
+               return;
+
+       for (fde = table->address, n = 0;
+            tableSize > sizeof(*fde) && tableSize - sizeof(*fde) >= *fde;
+            tableSize -= sizeof(*fde) + *fde, fde += 1 + *fde / sizeof(*fde)) {
+               const u32 *cie = cie_for_fde(fde, table);
+               signed ptrType;
+
+               if (cie == &not_fde)
+                       continue;
+               if (cie == NULL
+                   || cie == &bad_cie
+                   || (ptrType = fde_pointer_type(cie)) < 0)
+                       return;
+               ptr = (const u8 *)(fde + 2);
+               if (!read_pointer(&ptr,
+                                 (const u8 *)(fde + 1) + *fde,
+                                 ptrType, 0, 0))
+                       return;
+               ++n;
+       }
+
+       if (tableSize || !n)
+               return;
+
+       hdrSize = 4 + sizeof(unsigned long) + sizeof(unsigned int)
+               + 2 * n * sizeof(unsigned long);
+       dprintk(2, "Binary lookup table size for %s: %lu bytes", table->name, hdrSize);
+       header = alloc(hdrSize);
+       if (!header)
+               return;
+       header->version          = 1;
+       header->eh_frame_ptr_enc = DW_EH_PE_abs|DW_EH_PE_native;
+       header->fde_count_enc    = DW_EH_PE_abs|DW_EH_PE_data4;
+       header->table_enc        = DW_EH_PE_abs|DW_EH_PE_native;
+       put_unaligned((unsigned long)table->address, &header->eh_frame_ptr);
+       BUILD_BUG_ON(offsetof(typeof(*header), fde_count)
+                    % __alignof(typeof(header->fde_count)));
+       header->fde_count        = n;
+
+       BUILD_BUG_ON(offsetof(typeof(*header), table)
+                    % __alignof(typeof(*header->table)));
+       for (fde = table->address, tableSize = table->size, n = 0;
+            tableSize;
+            tableSize -= sizeof(*fde) + *fde, fde += 1 + *fde / sizeof(*fde)) {
+               const u32 *cie = fde + 1 - fde[1] / sizeof(*fde);
+
+               if (!fde[1])
+                       continue; /* this is a CIE */
+               ptr = (const u8 *)(fde + 2);
+               header->table[n].start = read_pointer(&ptr,
+                                                     (const u8 *)(fde + 1) + *fde,
+                                                     fde_pointer_type(cie), 0, 0);
+               header->table[n].fde = (unsigned long)fde;
+               ++n;
+       }
+       WARN_ON(n != header->fde_count);
+
+       sort(header->table,
+            n,
+            sizeof(*header->table),
+            cmp_eh_frame_hdr_table_entries,
+            swap_eh_frame_hdr_table_entries);
+
+       table->hdrsz = hdrSize;
+       smp_wmb();
+       table->header = (const void *)header;
+}
+
+static void *__init balloc(unsigned long sz)
+{
+       return __alloc_bootmem_nopanic(sz,
+                                      sizeof(unsigned int),
+                                      __pa(MAX_DMA_ADDRESS));
+}
+
+void __init unwind_setup(void)
+{
+       setup_unwind_table(&root_table, balloc);
 }
 
 #ifdef CONFIG_MODULES
 
+static struct unwind_table *last_table;
+
 /* Must be called with module_mutex held. */
 void *unwind_add_table(struct module *module,
                        const void *table_start,
@@ -191,7 +372,8 @@ void *unwind_add_table(struct module *module,
        init_unwind_table(table, module->name,
                          module->module_core, module->core_size,
                          module->module_init, module->init_size,
-                         table_start, table_size);
+                         table_start, table_size,
+                         NULL, 0);
 
        if (last_table)
                last_table->link = table;
@@ -301,9 +483,31 @@ static sleb128_t get_sleb128(const u8 **pcur, const u8 *end)
        return value;
 }
 
+static const u32 *cie_for_fde(const u32 *fde, const struct unwind_table *table)
+{
+       const u32 *cie;
+
+       if (!*fde || (*fde & (sizeof(*fde) - 1)))
+               return &bad_cie;
+       if (!fde[1])
+               return &not_fde; /* this is a CIE */
+       if ((fde[1] & (sizeof(*fde) - 1))
+           || fde[1] > (unsigned long)(fde + 1) - (unsigned long)table->address)
+               return NULL; /* this is not a valid FDE */
+       cie = fde + 1 - fde[1] / sizeof(*fde);
+       if (*cie <= sizeof(*cie) + 4
+           || *cie >= fde[1] - sizeof(*fde)
+           || (*cie & (sizeof(*cie) - 1))
+           || cie[1])
+               return NULL; /* this is not a (valid) CIE */
+       return cie;
+}
+
 static unsigned long read_pointer(const u8 **pLoc,
                                   const void *end,
-                                  signed ptrType)
+                                  signed ptrType,
+                                  unsigned long text_base,
+                                  unsigned long data_base)
 {
        unsigned long value = 0;
        union {
@@ -315,13 +519,17 @@ static unsigned long read_pointer(const u8 **pLoc,
                const unsigned long *pul;
        } ptr;
 
-       if (ptrType < 0 || ptrType == DW_EH_PE_omit)
+       if (ptrType < 0 || ptrType == DW_EH_PE_omit) {
+               dprintk(1, "Invalid pointer encoding %02X (%p,%p).", ptrType, *pLoc, end);
                return 0;
+       }
        ptr.p8 = *pLoc;
        switch(ptrType & DW_EH_PE_FORM) {
        case DW_EH_PE_data2:
-               if (end < (const void *)(ptr.p16u + 1))
+               if (end < (const void *)(ptr.p16u + 1)) {
+                       dprintk(1, "Data16 overrun (%p,%p).", ptr.p8, end);
                        return 0;
+               }
                if(ptrType & DW_EH_PE_signed)
                        value = get_unaligned(ptr.p16s++);
                else
@@ -329,8 +537,10 @@ static unsigned long read_pointer(const u8 **pLoc,
                break;
        case DW_EH_PE_data4:
 #ifdef CONFIG_64BIT
-               if (end < (const void *)(ptr.p32u + 1))
+               if (end < (const void *)(ptr.p32u + 1)) {
+                       dprintk(1, "Data32 overrun (%p,%p).", ptr.p8, end);
                        return 0;
+               }
                if(ptrType & DW_EH_PE_signed)
                        value = get_unaligned(ptr.p32s++);
                else
@@ -342,8 +552,10 @@ static unsigned long read_pointer(const u8 **pLoc,
                BUILD_BUG_ON(sizeof(u32) != sizeof(value));
 #endif
        case DW_EH_PE_native:
-               if (end < (const void *)(ptr.pul + 1))
+               if (end < (const void *)(ptr.pul + 1)) {
+                       dprintk(1, "DataUL overrun (%p,%p).", ptr.p8, end);
                        return 0;
+               }
                value = get_unaligned(ptr.pul++);
                break;
        case DW_EH_PE_leb128:
@@ -351,10 +563,14 @@ static unsigned long read_pointer(const u8 **pLoc,
                value = ptrType & DW_EH_PE_signed
                        ? get_sleb128(&ptr.p8, end)
                        : get_uleb128(&ptr.p8, end);
-               if ((const void *)ptr.p8 > end)
+               if ((const void *)ptr.p8 > end) {
+                       dprintk(1, "DataLEB overrun (%p,%p).", ptr.p8, end);
                        return 0;
+               }
                break;
        default:
+               dprintk(2, "Cannot decode pointer type %02X (%p,%p).",
+                       ptrType, ptr.p8, end);
                return 0;
        }
        switch(ptrType & DW_EH_PE_ADJUST) {
@@ -363,12 +579,33 @@ static unsigned long read_pointer(const u8 **pLoc,
        case DW_EH_PE_pcrel:
                value += (unsigned long)*pLoc;
                break;
+       case DW_EH_PE_textrel:
+               if (likely(text_base)) {
+                       value += text_base;
+                       break;
+               }
+               dprintk(2, "Text-relative encoding %02X (%p,%p), but zero text base.",
+                       ptrType, *pLoc, end);
+               return 0;
+       case DW_EH_PE_datarel:
+               if (likely(data_base)) {
+                       value += data_base;
+                       break;
+               }
+               dprintk(2, "Data-relative encoding %02X (%p,%p), but zero data base.",
+                       ptrType, *pLoc, end);
+               return 0;
        default:
+               dprintk(2, "Cannot adjust pointer type %02X (%p,%p).",
+                       ptrType, *pLoc, end);
                return 0;
        }
        if ((ptrType & DW_EH_PE_indirect)
-           && __get_user(value, (unsigned long *)value))
+           && probe_kernel_address((unsigned long *)value, value)) {
+               dprintk(1, "Cannot read indirect value %lx (%p,%p).",
+                       value, *pLoc, end);
                return 0;
+       }
        *pLoc = ptr.p8;
 
        return value;
@@ -411,7 +648,8 @@ static signed fde_pointer_type(const u32 *cie)
                        case 'P': {
                                        signed ptrType = *ptr++;
 
-                                       if (!read_pointer(&ptr, end, ptrType) || ptr > end)
+                                       if (!read_pointer(&ptr, end, ptrType, 0, 0)
+                                           || ptr > end)
                                                return -1;
                                }
                                break;
@@ -471,7 +709,8 @@ static int processCFI(const u8 *start,
                        case DW_CFA_nop:
                                break;
                        case DW_CFA_set_loc:
-                               if ((state->loc = read_pointer(&ptr.p8, end, ptrType)) == 0)
+                               state->loc = read_pointer(&ptr.p8, end, ptrType, 0, 0);
+                               if (state->loc == 0)
                                        result = 0;
                                break;
                        case DW_CFA_advance_loc1:
@@ -517,8 +756,10 @@ static int processCFI(const u8 *start,
                                        state->label = NULL;
                                        return 1;
                                }
-                               if (state->stackDepth >= MAX_STACK_DEPTH)
+                               if (state->stackDepth >= MAX_STACK_DEPTH) {
+                                       dprintk(1, "State stack overflow (%p,%p).", ptr.p8, end);
                                        return 0;
+                               }
                                state->stack[state->stackDepth++] = ptr.p8;
                                break;
                        case DW_CFA_restore_state:
@@ -533,8 +774,10 @@ static int processCFI(const u8 *start,
                                        result = processCFI(start, end, 0, ptrType, state);
                                        state->loc = loc;
                                        state->label = label;
-                               } else
+                               } else {
+                                       dprintk(1, "State stack underflow (%p,%p).", ptr.p8, end);
                                        return 0;
+                               }
                                break;
                        case DW_CFA_def_cfa:
                                state->cfa.reg = get_uleb128(&ptr.p8, end);
@@ -566,6 +809,7 @@ static int processCFI(const u8 *start,
                                break;
                        case DW_CFA_GNU_window_save:
                        default:
+                               dprintk(1, "Unrecognized CFI op %02X (%p,%p).", ptr.p8[-1], ptr.p8 - 1, end);
                                result = 0;
                                break;
                        }
@@ -581,12 +825,17 @@ static int processCFI(const u8 *start,
                        set_rule(*ptr.p8++ & 0x3f, Nowhere, 0, state);
                        break;
                }
-               if (ptr.p8 > end)
+               if (ptr.p8 > end) {
+                       dprintk(1, "Data overrun (%p,%p).", ptr.p8, end);
                        result = 0;
+               }
                if (result && targetLoc != 0 && targetLoc < state->loc)
                        return 1;
        }
 
+       if (result && ptr.p8 < end)
+               dprintk(1, "Data underrun (%p,%p).", ptr.p8, end);
+
        return result
           && ptr.p8 == end
           && (targetLoc == 0
@@ -603,53 +852,122 @@ int unwind(struct unwind_frame_info *frame)
 #define FRAME_REG(r, t) (((t *)frame)[reg_info[r].offs])
        const u32 *fde = NULL, *cie = NULL;
        const u8 *ptr = NULL, *end = NULL;
+       unsigned long pc = UNW_PC(frame) - frame->call_frame, sp;
        unsigned long startLoc = 0, endLoc = 0, cfa;
        unsigned i;
        signed ptrType = -1;
        uleb128_t retAddrReg = 0;
-       struct unwind_table *table;
+       const struct unwind_table *table;
        struct unwind_state state;
 
        if (UNW_PC(frame) == 0)
                return -EINVAL;
-       if ((table = find_table(UNW_PC(frame))) != NULL
+       if ((table = find_table(pc)) != NULL
            && !(table->size & (sizeof(*fde) - 1))) {
-               unsigned long tableSize = table->size;
-
-               for (fde = table->address;
-                    tableSize > sizeof(*fde) && tableSize - sizeof(*fde) >= *fde;
-                    tableSize -= sizeof(*fde) + *fde,
-                    fde += 1 + *fde / sizeof(*fde)) {
-                       if (!*fde || (*fde & (sizeof(*fde) - 1)))
-                               break;
-                       if (!fde[1])
-                               continue; /* this is a CIE */
-                       if ((fde[1] & (sizeof(*fde) - 1))
-                           || fde[1] > (unsigned long)(fde + 1)
-                                       - (unsigned long)table->address)
-                               continue; /* this is not a valid FDE */
-                       cie = fde + 1 - fde[1] / sizeof(*fde);
-                       if (*cie <= sizeof(*cie) + 4
-                           || *cie >= fde[1] - sizeof(*fde)
-                           || (*cie & (sizeof(*cie) - 1))
-                           || cie[1]
-                           || (ptrType = fde_pointer_type(cie)) < 0) {
-                               cie = NULL; /* this is not a (valid) CIE */
-                               continue;
+               const u8 *hdr = table->header;
+               unsigned long tableSize;
+
+               smp_rmb();
+               if (hdr && hdr[0] == 1) {
+                       switch(hdr[3] & DW_EH_PE_FORM) {
+                       case DW_EH_PE_native: tableSize = sizeof(unsigned long); break;
+                       case DW_EH_PE_data2: tableSize = 2; break;
+                       case DW_EH_PE_data4: tableSize = 4; break;
+                       case DW_EH_PE_data8: tableSize = 8; break;
+                       default: tableSize = 0; break;
+                       }
+                       ptr = hdr + 4;
+                       end = hdr + table->hdrsz;
+                       if (tableSize
+                           && read_pointer(&ptr, end, hdr[1], 0, 0)
+                              == (unsigned long)table->address
+                           && (i = read_pointer(&ptr, end, hdr[2], 0, 0)) > 0
+                           && i == (end - ptr) / (2 * tableSize)
+                           && !((end - ptr) % (2 * tableSize))) {
+                               do {
+                                       const u8 *cur = ptr + (i / 2) * (2 * tableSize);
+
+                                       startLoc = read_pointer(&cur,
+                                                               cur + tableSize,
+                                                               hdr[3], 0,
+                                                               (unsigned long)hdr);
+                                       if (pc < startLoc)
+                                               i /= 2;
+                                       else {
+                                               ptr = cur - tableSize;
+                                               i = (i + 1) / 2;
+                                       }
+                               } while (startLoc && i > 1);
+                               if (i == 1
+                                   && (startLoc = read_pointer(&ptr,
+                                                               ptr + tableSize,
+                                                               hdr[3], 0,
+                                                               (unsigned long)hdr)) != 0
+                                   && pc >= startLoc)
+                                       fde = (void *)read_pointer(&ptr,
+                                                                  ptr + tableSize,
+                                                                  hdr[3], 0,
+                                                                  (unsigned long)hdr);
                        }
+               }
+               if(hdr && !fde)
+                       dprintk(3, "Binary lookup for %lx failed.", pc);
+
+               if (fde != NULL) {
+                       cie = cie_for_fde(fde, table);
                        ptr = (const u8 *)(fde + 2);
-                       startLoc = read_pointer(&ptr,
-                                               (const u8 *)(fde + 1) + *fde,
-                                               ptrType);
-                       endLoc = startLoc
-                                + read_pointer(&ptr,
-                                               (const u8 *)(fde + 1) + *fde,
-                                               ptrType & DW_EH_PE_indirect
-                                               ? ptrType
-                                               : ptrType & (DW_EH_PE_FORM|DW_EH_PE_signed));
-                       if (UNW_PC(frame) >= startLoc && UNW_PC(frame) < endLoc)
-                               break;
-                       cie = NULL;
+                       if(cie != NULL
+                          && cie != &bad_cie
+                          && cie != &not_fde
+                          && (ptrType = fde_pointer_type(cie)) >= 0
+                          && read_pointer(&ptr,
+                                          (const u8 *)(fde + 1) + *fde,
+                                          ptrType, 0, 0) == startLoc) {
+                               if (!(ptrType & DW_EH_PE_indirect))
+                                       ptrType &= DW_EH_PE_FORM|DW_EH_PE_signed;
+                               endLoc = startLoc
+                                        + read_pointer(&ptr,
+                                                       (const u8 *)(fde + 1) + *fde,
+                                                       ptrType, 0, 0);
+                               if(pc >= endLoc)
+                                       fde = NULL;
+                       } else
+                               fde = NULL;
+                       if(!fde)
+                               dprintk(1, "Binary lookup result for %lx discarded.", pc);
+               }
+               if (fde == NULL) {
+                       for (fde = table->address, tableSize = table->size;
+                            cie = NULL, tableSize > sizeof(*fde)
+                            && tableSize - sizeof(*fde) >= *fde;
+                            tableSize -= sizeof(*fde) + *fde,
+                            fde += 1 + *fde / sizeof(*fde)) {
+                               cie = cie_for_fde(fde, table);
+                               if (cie == &bad_cie) {
+                                       cie = NULL;
+                                       break;
+                               }
+                               if (cie == NULL
+                                   || cie == &not_fde
+                                   || (ptrType = fde_pointer_type(cie)) < 0)
+                                       continue;
+                               ptr = (const u8 *)(fde + 2);
+                               startLoc = read_pointer(&ptr,
+                                                       (const u8 *)(fde + 1) + *fde,
+                                                       ptrType, 0, 0);
+                               if (!startLoc)
+                                       continue;
+                               if (!(ptrType & DW_EH_PE_indirect))
+                                       ptrType &= DW_EH_PE_FORM|DW_EH_PE_signed;
+                               endLoc = startLoc
+                                        + read_pointer(&ptr,
+                                                       (const u8 *)(fde + 1) + *fde,
+                                                       ptrType, 0, 0);
+                               if (pc >= startLoc && pc < endLoc)
+                                       break;
+                       }
+                       if(!fde)
+                               dprintk(3, "Linear lookup for %lx failed.", pc);
                }
        }
        if (cie != NULL) {
@@ -657,20 +975,34 @@ int unwind(struct unwind_frame_info *frame)
                state.cieEnd = ptr; /* keep here temporarily */
                ptr = (const u8 *)(cie + 2);
                end = (const u8 *)(cie + 1) + *cie;
+               frame->call_frame = 1;
                if ((state.version = *ptr) != 1)
                        cie = NULL; /* unsupported version */
                else if (*++ptr) {
                        /* check if augmentation size is first (and thus present) */
                        if (*ptr == 'z') {
-                               /* check for ignorable (or already handled)
-                                * nul-terminated augmentation string */
-                               while (++ptr < end && *ptr)
-                                       if (strchr("LPR", *ptr) == NULL)
+                               while (++ptr < end && *ptr) {
+                                       switch(*ptr) {
+                                       /* check for ignorable (or already handled)
+                                        * nul-terminated augmentation string */
+                                       case 'L':
+                                       case 'P':
+                                       case 'R':
+                                               continue;
+                                       case 'S':
+                                               frame->call_frame = 0;
+                                               continue;
+                                       default:
                                                break;
+                                       }
+                                       break;
+                               }
                        }
                        if (ptr >= end || *ptr)
                                cie = NULL;
                }
+               if(!cie)
+                       dprintk(1, "CIE unusable (%p,%p).", ptr, end);
                ++ptr;
        }
        if (cie != NULL) {
@@ -680,17 +1012,27 @@ int unwind(struct unwind_frame_info *frame)
                state.dataAlign = get_sleb128(&ptr, end);
                if (state.codeAlign == 0 || state.dataAlign == 0 || ptr >= end)
                        cie = NULL;
-               else {
+               else if (UNW_PC(frame) % state.codeAlign
+                        || UNW_SP(frame) % sleb128abs(state.dataAlign)) {
+                       dprintk(1, "Input pointer(s) misaligned (%lx,%lx).",
+                               UNW_PC(frame), UNW_SP(frame));
+                       return -EPERM;
+               } else {
                        retAddrReg = state.version <= 1 ? *ptr++ : get_uleb128(&ptr, end);
                        /* skip augmentation */
-                       if (((const char *)(cie + 2))[1] == 'z')
-                               ptr += get_uleb128(&ptr, end);
+                       if (((const char *)(cie + 2))[1] == 'z') {
+                               uleb128_t augSize = get_uleb128(&ptr, end);
+
+                               ptr += augSize;
+                       }
                        if (ptr > end
                           || retAddrReg >= ARRAY_SIZE(reg_info)
                           || REG_INVALID(retAddrReg)
                           || reg_info[retAddrReg].width != sizeof(unsigned long))
                                cie = NULL;
                }
+               if(!cie)
+                       dprintk(1, "CIE validation failed (%p,%p).", ptr, end);
        }
        if (cie != NULL) {
                state.cieStart = ptr;
@@ -704,13 +1046,15 @@ int unwind(struct unwind_frame_info *frame)
                        if ((ptr += augSize) > end)
                                fde = NULL;
                }
+               if(!fde)
+                       dprintk(1, "FDE validation failed (%p,%p).", ptr, end);
        }
        if (cie == NULL || fde == NULL) {
 #ifdef CONFIG_FRAME_POINTER
                unsigned long top, bottom;
-#endif
 
-#ifdef CONFIG_FRAME_POINTER
+               if ((UNW_SP(frame) | UNW_FP(frame)) % sizeof(unsigned long))
+                       return -EPERM;
                top = STACK_TOP(frame->task);
                bottom = STACK_BOTTOM(frame->task);
 # if FRAME_RETADDR_OFFSET < 0
@@ -726,18 +1070,19 @@ int unwind(struct unwind_frame_info *frame)
                        & (sizeof(unsigned long) - 1))) {
                        unsigned long link;
 
-                       if (!__get_user(link,
+                       if (!probe_kernel_address(
                                        (unsigned long *)(UNW_FP(frame)
-                                                         + FRAME_LINK_OFFSET))
+                                                         + FRAME_LINK_OFFSET),
+                                                 link)
 # if FRAME_RETADDR_OFFSET < 0
                           && link > bottom && link < UNW_FP(frame)
 # else
                           && link > UNW_FP(frame) && link < bottom
 # endif
                           && !(link & (sizeof(link) - 1))
-                          && !__get_user(UNW_PC(frame),
+                          && !probe_kernel_address(
                                          (unsigned long *)(UNW_FP(frame)
-                                                           + FRAME_RETADDR_OFFSET))) {
+                                                           + FRAME_RETADDR_OFFSET), UNW_PC(frame))) {
                                UNW_SP(frame) = UNW_FP(frame) + FRAME_RETADDR_OFFSET
 # if FRAME_RETADDR_OFFSET < 0
                                        -
@@ -755,14 +1100,22 @@ int unwind(struct unwind_frame_info *frame)
        state.org = startLoc;
        memcpy(&state.cfa, &badCFA, sizeof(state.cfa));
        /* process instructions */
-       if (!processCFI(ptr, end, UNW_PC(frame), ptrType, &state)
+       if (!processCFI(ptr, end, pc, ptrType, &state)
           || state.loc > endLoc
           || state.regs[retAddrReg].where == Nowhere
           || state.cfa.reg >= ARRAY_SIZE(reg_info)
           || reg_info[state.cfa.reg].width != sizeof(unsigned long)
-          || state.cfa.offs % sizeof(unsigned long))
+          || FRAME_REG(state.cfa.reg, unsigned long) % sizeof(unsigned long)
+          || state.cfa.offs % sizeof(unsigned long)) {
+               dprintk(1, "Unusable unwind info (%p,%p).", ptr, end);
                return -EIO;
+       }
        /* update frame */
+#ifndef CONFIG_AS_CFI_SIGNAL_FRAME
+       if(frame->call_frame
+          && !UNW_DEFAULT_RA(state.regs[retAddrReg], state.dataAlign))
+               frame->call_frame = 0;
+#endif
        cfa = FRAME_REG(state.cfa.reg, unsigned long) + state.cfa.offs;
        startLoc = min((unsigned long)UNW_SP(frame), cfa);
        endLoc = max((unsigned long)UNW_SP(frame), cfa);
@@ -775,10 +1128,14 @@ int unwind(struct unwind_frame_info *frame)
 #else
 # define CASES CASE(8); CASE(16); CASE(32); CASE(64)
 #endif
+       pc = UNW_PC(frame);
+       sp = UNW_SP(frame);
        for (i = 0; i < ARRAY_SIZE(state.regs); ++i) {
                if (REG_INVALID(i)) {
                        if (state.regs[i].where == Nowhere)
                                continue;
+                       dprintk(1, "Cannot restore register %u (%d).",
+                               i, state.regs[i].where);
                        return -EIO;
                }
                switch(state.regs[i].where) {
@@ -787,8 +1144,11 @@ int unwind(struct unwind_frame_info *frame)
                case Register:
                        if (state.regs[i].value >= ARRAY_SIZE(reg_info)
                           || REG_INVALID(state.regs[i].value)
-                          || reg_info[i].width > reg_info[state.regs[i].value].width)
+                          || reg_info[i].width > reg_info[state.regs[i].value].width) {
+                               dprintk(1, "Cannot restore register %u from register %lu.",
+                                       i, state.regs[i].value);
                                return -EIO;
+                       }
                        switch(reg_info[state.regs[i].value].width) {
 #define CASE(n) \
                        case sizeof(u##n): \
@@ -798,6 +1158,9 @@ int unwind(struct unwind_frame_info *frame)
                        CASES;
 #undef CASE
                        default:
+                               dprintk(1, "Unsupported register size %u (%lu).",
+                                       reg_info[state.regs[i].value].width,
+                                       state.regs[i].value);
                                return -EIO;
                        }
                        break;
@@ -822,12 +1185,17 @@ int unwind(struct unwind_frame_info *frame)
                        CASES;
 #undef CASE
                        default:
+                               dprintk(1, "Unsupported register size %u (%u).",
+                                       reg_info[i].width, i);
                                return -EIO;
                        }
                        break;
                case Value:
-                       if (reg_info[i].width != sizeof(unsigned long))
+                       if (reg_info[i].width != sizeof(unsigned long)) {
+                               dprintk(1, "Unsupported value size %u (%u).",
+                                       reg_info[i].width, i);
                                return -EIO;
+                       }
                        FRAME_REG(i, unsigned long) = cfa + state.regs[i].value
                                                            * state.dataAlign;
                        break;
@@ -839,15 +1207,20 @@ int unwind(struct unwind_frame_info *frame)
                                    % sizeof(unsigned long)
                                    || addr < startLoc
                                    || addr + sizeof(unsigned long) < addr
-                                   || addr + sizeof(unsigned long) > endLoc)
+                                   || addr + sizeof(unsigned long) > endLoc) {
+                                       dprintk(1, "Bad memory location %lx (%lx).",
+                                               addr, state.regs[i].value);
                                        return -EIO;
+                               }
                                switch(reg_info[i].width) {
 #define CASE(n)     case sizeof(u##n): \
-                                       __get_user(FRAME_REG(i, u##n), (u##n *)addr); \
+                                       probe_kernel_address((u##n *)addr, FRAME_REG(i, u##n)); \
                                        break
                                CASES;
 #undef CASE
                                default:
+                                       dprintk(1, "Unsupported memory size %u (%u).",
+                                               reg_info[i].width, i);
                                        return -EIO;
                                }
                        }
@@ -855,6 +1228,17 @@ int unwind(struct unwind_frame_info *frame)
                }
        }
 
+       if (UNW_PC(frame) % state.codeAlign
+           || UNW_SP(frame) % sleb128abs(state.dataAlign)) {
+               dprintk(1, "Output pointer(s) misaligned (%lx,%lx).",
+                       UNW_PC(frame), UNW_SP(frame));
+               return -EIO;
+       }
+       if (pc == UNW_PC(frame) && sp == UNW_SP(frame)) {
+               dprintk(1, "No progress (%lx,%lx).", pc, sp);
+               return -EIO;
+       }
+
        return 0;
 #undef CASES
 #undef FRAME_REG
@@ -866,6 +1250,7 @@ int unwind_init_frame_info(struct unwind_frame_info *info,
                            /*const*/ struct pt_regs *regs)
 {
        info->task = tsk;
+       info->call_frame = 0;
        arch_unw_init_frame_info(info, regs);
 
        return 0;
@@ -879,6 +1264,7 @@ int unwind_init_blocked(struct unwind_frame_info *info,
                         struct task_struct *tsk)
 {
        info->task = tsk;
+       info->call_frame = 0;
        arch_unw_init_blocked(info);
 
        return 0;
@@ -894,6 +1280,7 @@ int unwind_init_running(struct unwind_frame_info *info,
                         void *arg)
 {
        info->task = current;
+       info->call_frame = 0;
 
        return arch_unwind_init_running(info, callback, arg);
 }