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[IA64] unwind.c uses wrong unat from switch_stack 

unwind.c can read the wrong unat bits from switch_stack.
sw->caller_unat is the value of ar.unat when the task was blocked.
sw->ar_unat is the value of ar.unat after doing st8.spill for r4-7.
IOW, ar_unat is caller_unat with 4 bits changed.

unw_access_gr() uses sw->ar_unat for r4-7 (correct), but it also uses
sw->ar_unat for other scratch registers (incorrect).  sw->ar_unat
should only be used for r4-7, everything else should use
sw->caller_unat, unless modified by unwind info.  Using sw->ar_unat
risks picking up the 4 bits that were overwritten when r4-7 were saved.

Also this line is wrong
	unw.sw_off[unw.preg_index[UNW_REG_PFS]] = SW(AR_UNAT);
and should be
	unw.sw_off[unw.preg_index[UNW_REG_PFS]] = SW(AR_PFS);

Signed-off-by: Keith Owens <kaos@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
This commit is contained in:
Keith Owens 2005-07-21 23:41:00 -07:00 committed by Tony Luck
parent d108919b2b
commit b833961bd3
1 changed files with 6 additions and 6 deletions
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12
arch/ia64/kernel/unwind.c
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@ -362,7 +362,7 @@ unw_access_gr (struct unw_frame_info *info, int regnum, unsigned long *val, char
if (info->pri_unat_loc)
nat_addr = info->pri_unat_loc;
else
nat_addr = &info->sw->ar_unat;
nat_addr = &info->sw->caller_unat;
nat_mask = (1UL << ((long) addr & 0x1f8)/8);
}
} else {
@ -524,7 +524,7 @@ unw_access_ar (struct unw_frame_info *info, int regnum, unsigned long *val, int
case UNW_AR_UNAT:
addr = info->unat_loc;
if (!addr)
addr = &info->sw->ar_unat;
addr = &info->sw->caller_unat;
break;
case UNW_AR_LC:
@ -1775,7 +1775,7 @@ run_script (struct unw_script *script, struct unw_frame_info *state)
case UNW_INSN_SETNAT_MEMSTK:
if (!state->pri_unat_loc)
state->pri_unat_loc = &state->sw->ar_unat;
state->pri_unat_loc = &state->sw->caller_unat;
/* register off. is a multiple of 8, so the least 3 bits (type) are 0 */
s[dst+1] = ((unsigned long) state->pri_unat_loc - s[dst]) | UNW_NAT_MEMSTK;
break;
@ -2243,11 +2243,11 @@ unw_init (void)
if (8*sizeof(unw_hash_index_t) < UNW_LOG_HASH_SIZE)
unw_hash_index_t_is_too_narrow();
unw.sw_off[unw.preg_index[UNW_REG_PRI_UNAT_GR]] = SW(AR_UNAT);
unw.sw_off[unw.preg_index[UNW_REG_PRI_UNAT_GR]] = SW(CALLER_UNAT);
unw.sw_off[unw.preg_index[UNW_REG_BSPSTORE]] = SW(AR_BSPSTORE);
unw.sw_off[unw.preg_index[UNW_REG_PFS]] = SW(AR_UNAT);
unw.sw_off[unw.preg_index[UNW_REG_PFS]] = SW(AR_PFS);
unw.sw_off[unw.preg_index[UNW_REG_RP]] = SW(B0);
unw.sw_off[unw.preg_index[UNW_REG_UNAT]] = SW(AR_UNAT);
unw.sw_off[unw.preg_index[UNW_REG_UNAT]] = SW(CALLER_UNAT);
unw.sw_off[unw.preg_index[UNW_REG_PR]] = SW(PR);
unw.sw_off[unw.preg_index[UNW_REG_LC]] = SW(AR_LC);
unw.sw_off[unw.preg_index[UNW_REG_FPSR]] = SW(AR_FPSR);