summaryrefslogtreecommitdiffstats
path: root/kernel/unwind.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/unwind.c')
-rw-r--r--kernel/unwind.c498
1 files changed, 431 insertions, 67 deletions
diff --git a/kernel/unwind.c b/kernel/unwind.c
index 2e2368607aab..09c261329249 100644
--- a/kernel/unwind.c
+++ b/kernel/unwind.c
@@ -11,13 +11,16 @@
#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 {
@@ -100,6 +104,8 @@ 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;
@@ -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;
}
@@ -169,7 +211,144 @@ 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
@@ -193,7 +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;
@@ -303,9 +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 {
@@ -317,13 +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
@@ -331,8 +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
@@ -344,8 +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:
@@ -353,10 +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) {
@@ -365,12 +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;
@@ -413,7 +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;
@@ -473,7 +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:
@@ -519,8 +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:
@@ -535,8 +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);
@@ -568,6 +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;
}
@@ -583,12 +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
@@ -605,54 +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;
+ 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(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 (pc >= startLoc && pc < 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) {
@@ -686,6 +1001,8 @@ int unwind(struct unwind_frame_info *frame)
if (ptr >= end || *ptr)
cie = NULL;
}
+ if(!cie)
+ dprintk(1, "CIE unusable (%p,%p).", ptr, end);
++ptr;
}
if (cie != NULL) {
@@ -695,17 +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;
@@ -719,13 +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
@@ -741,18 +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
-
@@ -775,8 +1105,11 @@ int unwind(struct unwind_frame_info *frame)
|| 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
@@ -795,10 +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) {
@@ -807,8 +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): \
@@ -818,6 +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;
@@ -842,12 +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;
@@ -859,15 +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;
}
}
@@ -875,6 +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
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-26 22:01:26 +0000