[PATCH 2/3] ARC: dw2 unwind: factor CIE specifics for .eh_frame/.debug_frame

[Vineet Gupta]

This paves way for switching to .eh_frame based unwindiing

Signed-off-by: Vineet Gupta 
---
 arch/arc/kernel/unwind.c | 25 ++---
 1 file 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 0xUL
+
 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] == 0x)
+   if (fde[1] == CIE_ID)
continue;   /* this is a CIE */
ptr = (const u8 *)(fde + 2);
header->table[n].start = read_pointer(,
@@ -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 _cie;
 
-   if (fde[1] == 0x)
+   if (fde[1] == CIE_ID)
return _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] != 0x))
+   || (cie[1] != CIE_ID))
return NULL;/* this is not a (valid) CIE */
return cie;
 }
-- 
2.7.4

[PATCH 2/3] ARC: dw2 unwind: factor CIE specifics for .eh_frame/.debug_frame

[Vineet Gupta]

This paves way for switching to .eh_frame based unwindiing

Signed-off-by: Vineet Gupta 
---
 arch/arc/kernel/unwind.c | 25 ++---
 1 file 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 0xUL
+
 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] == 0x)
+   if (fde[1] == CIE_ID)
continue;   /* this is a CIE */
ptr = (const u8 *)(fde + 2);
header->table[n].start = read_pointer(,
@@ -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 _cie;
 
-   if (fde[1] == 0x)
+   if (fde[1] == CIE_ID)
return _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] != 0x))
+   || (cie[1] != CIE_ID))
return NULL;/* this is not a (valid) CIE */
return cie;
 }
-- 
2.7.4