[PATCH 15/17] ARC: dw2 unwind: Single exit point for instrumentation

From: Vineet Gupta
Date: Thu Dec 03 2015 - 07:46:33 EST


Signed-off-by: Vineet Gupta <vgupta@xxxxxxxxxxxx>
---
arch/arc/kernel/unwind.c | 31 +++++++++++++++++++------------
1 file changed, 19 insertions(+), 12 deletions(-)

diff --git a/arch/arc/kernel/unwind.c b/arch/arc/kernel/unwind.c
index 4f739716f908..e02d974ea789 100644
--- a/arch/arc/kernel/unwind.c
+++ b/arch/arc/kernel/unwind.c
@@ -904,6 +904,7 @@ int arc_unwind(struct unwind_frame_info *frame)
unsigned long *fptr;
unsigned long addr;
struct eh_frame_header *hdr;
+ int ret = -EINVAL;

unw_debug("\nUNWIND FRAME: -------------------------------------\n");
unw_debug("PC\t\t: 0x%lx %pS\nr31 [BLINK]\t: 0x%lx %pS\nr28 [SP]\t: 0x%lx\nr27 [FP]\t: 0x%lx\n",
@@ -912,7 +913,7 @@ int arc_unwind(struct unwind_frame_info *frame)
UNW_SP(frame), UNW_FP(frame));

if (UNW_PC(frame) == 0)
- return -EINVAL;
+ goto bad_unw;

#ifdef UNWIND_DEBUG0
{
@@ -926,11 +927,11 @@ int arc_unwind(struct unwind_frame_info *frame)

table = find_table(pc);
if (table == NULL)
- return -EINVAL;
+ goto bad_unw;

hdr = table->header;
if (hdr == NULL)
- return -EINVAL;
+ goto bad_unw;

s = i = 0;
e = hdr->fde_count - 1;
@@ -948,7 +949,7 @@ int arc_unwind(struct unwind_frame_info *frame)
if (pc >= startLoc)
fde = (u32 *)hdr->table[i].fde;
else
- return -EINVAL;
+ goto bad_unw;

memset(&state, 0, sizeof(state));
ptr = (const u8 *)(fde + 2);
@@ -956,7 +957,7 @@ int arc_unwind(struct unwind_frame_info *frame)

ptrType = table->cie.fde_pointer_type;
if (read_pointer(&ptr, end, ptrType) != startLoc)
- return -EINVAL;
+ goto bad_unw;

if (!(ptrType & DW_EH_PE_indirect))
ptrType &= DW_EH_PE_FORM | DW_EH_PE_signed;
@@ -967,14 +968,15 @@ int arc_unwind(struct unwind_frame_info *frame)
if (pc >= endLoc) {
unw_debug("Unwindo info missing for PC %lx: {%lx,%lx}\n",
pc, startLoc, endLoc);
- return -EINVAL;
+ ret = -ENOENT;
+ goto bad_unw;
}

if (table->cie.aug) {
uleb128_t augSize = get_uleb128(&ptr, end);

if ((ptr += augSize) > end)
- return -EINVAL;
+ goto bad_unw;
}

state.org = state.loc = startLoc;
@@ -995,8 +997,10 @@ int arc_unwind(struct unwind_frame_info *frame)
|| state.loc > endLoc
/* || state.regs[retAddrReg].where == Nowhere */
|| state.cfa.reg >= ARRAY_SIZE(reg_info)
- || state.cfa.offs % sizeof(unsigned long))
- return -EIO;
+ || state.cfa.offs % sizeof(unsigned long)) {
+ ret = -EIO;
+ goto bad_unw;
+ }

cfa = FRAME_REG(state.cfa.reg, unsigned long) + state.cfa.offs;
startLoc = min_t(unsigned long, UNW_SP(frame), cfa);
@@ -1022,7 +1026,7 @@ int arc_unwind(struct unwind_frame_info *frame)
for (i = 0; state.has_cfa_register && i < ARRAY_SIZE(state.regs); ++i) {
if (state.regs[i].where == Register) {
if (state.regs[i].value >= ARRAY_SIZE(reg_info))
- return -EIO;
+ goto bad_unw;

state.regs[i].value = FRAME_REG(state.regs[i].value, unsigned long);
}
@@ -1054,7 +1058,7 @@ int arc_unwind(struct unwind_frame_info *frame)
|| addr < startLoc
|| addr + sizeof(unsigned long) < addr
|| addr + sizeof(unsigned long) > endLoc)
- return -EIO;
+ goto bad_unw;

FRAME_REG(i, unsigned long) = *(unsigned long *)addr;
break;
@@ -1062,7 +1066,10 @@ int arc_unwind(struct unwind_frame_info *frame)
unw_debug("r%d: 0x%lx\n", i, *fptr);
}

- return 0;
+ ret = 0;
+bad_unw:
+
+ return ret;
#undef FRAME_REG
}
EXPORT_SYMBOL(arc_unwind);
--
1.9.1

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