#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
+#include <linux/kallsyms.h>
#include <asm/uaccess.h>
+#include <asm/assembly.h>
#include <asm/unwind.h>
static inline const struct unwind_table_entry *
find_unwind_entry_in_table(const struct unwind_table *table, unsigned long addr)
{
- const struct unwind_table_entry *e = 0;
+ const struct unwind_table_entry *e = NULL;
unsigned long lo, hi, mid;
- for (lo = 0, hi = table->length; lo < hi; )
- {
- mid = (lo + hi) / 2;
+ lo = 0;
+ hi = table->length - 1;
+
+ while (lo <= hi) {
+ mid = (hi - lo) / 2 + lo;
e = &table->table[mid];
if (addr < e->region_start)
- hi = mid;
+ hi = mid - 1;
else if (addr > e->region_end)
lo = mid + 1;
else
- break;
+ return e;
}
- return e;
+ return NULL;
}
-static inline const struct unwind_table_entry *
+static const struct unwind_table_entry *
find_unwind_entry(unsigned long addr)
{
struct unwind_table *table = unwind_tables;
addr <= kernel_unwind_table.end)
e = find_unwind_entry_in_table(&kernel_unwind_table, addr);
else
- for (; table; table = table->next)
- {
+ for (; table; table = table->next) {
if (addr >= table->start &&
addr <= table->end)
e = find_unwind_entry_in_table(table, addr);
table->next = NULL;
for (; start <= end; start++) {
+ if (start < end &&
+ start->region_end > (start+1)->region_start) {
+ printk("WARNING: Out of order unwind entry! %p and %p\n", start, start+1);
+ }
+
start->region_start += base_addr;
start->region_end += base_addr;
}
table = kmalloc(sizeof(struct unwind_table), GFP_USER);
if (table == NULL)
- return 0;
+ return NULL;
unwind_table_init(table, name, base_addr, gp, start, end);
spin_lock_irqsave(&unwind_lock, flags);
if (unwind_tables)
int looking_for_rp, rpoffset = 0;
e = find_unwind_entry(info->ip);
- if (!e) {
+ if (e == NULL) {
unsigned long sp;
extern char _stext[], _etext[];
dbg("Cannot find unwind entry for 0x%lx; forced unwinding\n", info->ip);
+#ifdef CONFIG_KALLSYMS
+ /* Handle some frequent special cases.... */
+ {
+ char symname[KSYM_NAME_LEN+1];
+ char *modname;
+ unsigned long symsize, offset;
+
+ kallsyms_lookup(info->ip, &symsize, &offset,
+ &modname, symname);
+
+ dbg("info->ip = 0x%lx, name = %s\n", info->ip, symname);
+
+ if (strcmp(symname, "_switch_to_ret") == 0) {
+ info->prev_sp = info->sp - CALLEE_SAVE_FRAME_SIZE;
+ info->prev_ip = *(unsigned long *)(info->prev_sp - RP_OFFSET);
+ dbg("_switch_to_ret @ %lx - setting "
+ "prev_sp=%lx prev_ip=%lx\n",
+ info->ip, info->prev_sp,
+ info->prev_ip);
+ return;
+ } else if (strcmp(symname, "ret_from_kernel_thread") == 0 ||
+ strcmp(symname, "syscall_exit") == 0) {
+ info->prev_ip = info->prev_sp = 0;
+ return;
+ }
+ }
+#endif
+
/* Since we are doing the unwinding blind, we don't know if
we are adjusting the stack correctly or extracting the rp
correctly. The rp is checked to see if it belongs to the
modules. */
sp = info->sp & ~63;
do {
- info->prev_sp = sp - 64;
-
- /* FIXME: what happens if we unwind too far so that
- sp no longer falls in a mapped kernel page? */
-#ifndef __LP64__
- info->prev_ip = *(unsigned long *)(info->prev_sp - 20);
-#else
- info->prev_ip = *(unsigned long *)(info->prev_sp - 16);
-#endif
+ unsigned long tmp;
+ info->prev_sp = sp - 64;
+ info->prev_ip = 0;
+ if (get_user(tmp, (unsigned long *)(info->prev_sp - RP_OFFSET)))
+ break;
+ info->prev_ip = tmp;
sp = info->prev_sp;
} while (info->prev_ip < (unsigned long)_stext ||
info->prev_ip > (unsigned long)_etext);
- dbg("analyzing func @ %lx with no unwind info, setting prev_sp=%lx prev_ip=%lx\n", info->ip, info->prev_sp, info->prev_ip);
- } else {
+ info->rp = 0;
- dbg("e->start = 0x%x, e->end = 0x%x, Save_SP = %d, Save_RP = %d size = %u\n",
- e->region_start, e->region_end, e->Save_SP, e->Save_RP, e->Total_frame_size);
+ dbg("analyzing func @ %lx with no unwind info, setting "
+ "prev_sp=%lx prev_ip=%lx\n", info->ip,
+ info->prev_sp, info->prev_ip);
+ } else {
+ dbg("e->start = 0x%x, e->end = 0x%x, Save_SP = %d, "
+ "Save_RP = %d size = %u\n", e->region_start,
+ e->region_end, e->Save_SP, e->Save_RP,
+ e->Total_frame_size);
looking_for_rp = e->Save_RP;
for (npc = e->region_start;
- (frame_size < (e->Total_frame_size << 3) || looking_for_rp) &&
+ (frame_size < (e->Total_frame_size << 3) ||
+ looking_for_rp) &&
npc < info->ip;
npc += 4) {
/* ldo X(sp), sp, or stwm X,D(sp) */
frame_size += (insn & 0x1 ? -1 << 13 : 0) |
((insn & 0x3fff) >> 1);
- dbg("analyzing func @ %lx, insn=%08x @ %lx, frame_size = %ld\n", info->ip, insn, npc, frame_size);
- } else if ((insn & 0xffe00008) == 0x7ec00008) {
+ dbg("analyzing func @ %lx, insn=%08x @ "
+ "%lx, frame_size = %ld\n", info->ip,
+ insn, npc, frame_size);
+ } else if ((insn & 0xffe00008) == 0x73c00008) {
/* std,ma X,D(sp) */
frame_size += (insn & 0x1 ? -1 << 13 : 0) |
(((insn >> 4) & 0x3ff) << 3);
- dbg("analyzing func @ %lx, insn=%08x @ %lx, frame_size = %ld\n", info->ip, insn, npc, frame_size);
+ dbg("analyzing func @ %lx, insn=%08x @ "
+ "%lx, frame_size = %ld\n", info->ip,
+ insn, npc, frame_size);
} else if (insn == 0x6bc23fd9) {
/* stw rp,-20(sp) */
rpoffset = 20;
looking_for_rp = 0;
- dbg("analyzing func @ %lx, insn=stw rp,-20(sp) @ %lx\n", info->ip, npc);
+ dbg("analyzing func @ %lx, insn=stw rp,"
+ "-20(sp) @ %lx\n", info->ip, npc);
} else if (insn == 0x0fc212c1) {
/* std rp,-16(sr0,sp) */
rpoffset = 16;
looking_for_rp = 0;
- dbg("analyzing func @ %lx, insn=std rp,-16(sp) @ %lx\n", info->ip, npc);
+ dbg("analyzing func @ %lx, insn=std rp,"
+ "-16(sp) @ %lx\n", info->ip, npc);
}
}
info->prev_ip = info->rp;
info->rp = 0;
- dbg("analyzing func @ %lx, setting prev_sp=%lx prev_ip=%lx\n", info->ip, info->prev_sp, info->prev_ip);
+ dbg("analyzing func @ %lx, setting prev_sp=%lx "
+ "prev_ip=%lx npc=%lx\n", info->ip, info->prev_sp,
+ info->prev_ip, npc);
}
}
info->ip = ip;
info->rp = rp;
- dbg("(%d) Start unwind from sp=%08lx ip=%08lx\n", t ? (int)t->pid : 0, info->sp, info->ip);
+ dbg("(%d) Start unwind from sp=%08lx ip=%08lx\n",
+ t ? (int)t->pid : -1, info->sp, info->ip);
}
void unwind_frame_init_from_blocked_task(struct unwind_frame_info *info, struct task_struct *t)
next_frame->prev_sp = 0;
next_frame->prev_ip = 0;
- dbg("(%d) Continue unwind to sp=%08lx ip=%08lx\n", (int)next_frame->t->pid, next_frame->sp, next_frame->ip);
+ dbg("(%d) Continue unwind to sp=%08lx ip=%08lx\n",
+ next_frame->t ? (int)next_frame->t->pid : -1,
+ next_frame->sp, next_frame->ip);
return 0;
}
git://git.onelab.eu / linux-2.6.git / blobdiff