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authorVineet Gupta <vgupta@synopsys.com>2015-11-23 22:30:35 +0530
committerVineet Gupta <vgupta@synopsys.com>2016-09-30 14:48:19 -0700
commitd040876b4aad0c157c5c95779128b71a121ff27d (patch)
tree8efde7afdd04f791d17a0e61008b79c364e7f4c4 /arch/arc/kernel/unwind.c
parent94f4fb0841bfa5c1088a1b3a879a65bdd675ecd2 (diff)
download96b-common-d040876b4aad0c157c5c95779128b71a121ff27d.tar.gz
ARC: dw2 unwind: factor CIE specifics for .eh_frame/.debug_frame
This paves way for switching to .eh_frame based unwindiing Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch/arc/kernel/unwind.c')
-rw-r--r--arch/arc/kernel/unwind.c25
1 files changed, 18 insertions, 7 deletions
diff --git a/arch/arc/kernel/unwind.c b/arch/arc/kernel/unwind.c
index 0587bf121d11..4e5dbe7617a1 100644
--- a/arch/arc/kernel/unwind.c
+++ b/arch/arc/kernel/unwind.c
@@ -111,6 +111,8 @@ UNW_REGISTER_INFO};
#define DW_EH_PE_indirect 0x80
#define DW_EH_PE_omit 0xff
+#define CIE_ID 0xffffffffUL
+
typedef unsigned long uleb128_t;
typedef signed long sleb128_t;
@@ -232,6 +234,7 @@ void __init arc_unwind_init(void)
static const u32 bad_cie, not_fde;
static const u32 *cie_for_fde(const u32 *fde, const struct unwind_table *);
+static const u32 *__cie_for_fde(const u32 *fde);
static signed fde_pointer_type(const u32 *cie);
struct eh_frame_hdr_table_entry {
@@ -338,10 +341,9 @@ static void init_unwind_hdr(struct unwind_table *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); */
- const u32 *cie = (const u32 *)(fde[1]);
+ const u32 *cie = __cie_for_fde(fde);
- if (fde[1] == 0xffffffff)
+ if (fde[1] == CIE_ID)
continue; /* this is a CIE */
ptr = (const u8 *)(fde + 2);
header->table[n].start = read_pointer(&ptr,
@@ -504,6 +506,16 @@ static sleb128_t get_sleb128(const u8 **pcur, const u8 *end)
return value;
}
+static const u32 *__cie_for_fde(const u32 *fde)
+{
+ const u32 *cie;
+
+ /* cie = fde + 1 - fde[1] / sizeof(*fde); */
+ cie = (u32 *) fde[1];
+
+ return cie;
+}
+
static const u32 *cie_for_fde(const u32 *fde, const struct unwind_table *table)
{
const u32 *cie;
@@ -511,19 +523,18 @@ static const u32 *cie_for_fde(const u32 *fde, const struct unwind_table *table)
if (!*fde || (*fde & (sizeof(*fde) - 1)))
return &bad_cie;
- if (fde[1] == 0xffffffff)
+ if (fde[1] == CIE_ID)
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); */
- cie = (u32 *) fde[1];
+ cie = __cie_for_fde(fde);
if (*cie <= sizeof(*cie) + 4 || *cie >= fde[1] - sizeof(*fde)
|| (*cie & (sizeof(*cie) - 1))
- || (cie[1] != 0xffffffff))
+ || (cie[1] != CIE_ID))
return NULL; /* this is not a (valid) CIE */
return cie;
}