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ARC: dw2 unwind: factor CIE specifics for .eh_frame/.debug_frame

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This paves way for switching to .eh_frame based unwindiing

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
This commit is contained in:
Vineet Gupta 2015-11-23 22:30:35 +05:30
parent 94f4fb0841
commit d040876b4a
1 changed files with 18 additions and 7 deletions
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25
arch/arc/kernel/unwind.c
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@ -111,6 +111,8 @@ UNW_REGISTER_INFO};
#define DW_EH_PE_indirect 0x80 #define DW_EH_PE_indirect 0x80
#define DW_EH_PE_omit 0xff #define DW_EH_PE_omit 0xff
#define CIE_ID 0xffffffffUL
typedef unsigned long uleb128_t; typedef unsigned long uleb128_t;
typedef signed long sleb128_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 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, const struct unwind_table *);
static const u32 *__cie_for_fde(const u32 *fde);
static signed fde_pointer_type(const u32 *cie); static signed fde_pointer_type(const u32 *cie);
struct eh_frame_hdr_table_entry { 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; for (fde = table->address, tableSize = table->size, n = 0;
tableSize; tableSize;
tableSize -= sizeof(*fde) + *fde, fde += 1 + *fde / sizeof(*fde)) { tableSize -= sizeof(*fde) + *fde, fde += 1 + *fde / sizeof(*fde)) {
/* const u32 *cie = fde + 1 - fde[1] / sizeof(*fde); */ const u32 *cie = __cie_for_fde(fde);
const u32 *cie = (const u32 *)(fde[1]);
if (fde[1] == 0xffffffff) if (fde[1] == CIE_ID)
continue; /* this is a CIE */ continue; /* this is a CIE */
ptr = (const u8 *)(fde + 2); ptr = (const u8 *)(fde + 2);
header->table[n].start = read_pointer(&ptr, header->table[n].start = read_pointer(&ptr,
@ -504,6 +506,16 @@ static sleb128_t get_sleb128(const u8 **pcur, const u8 *end)
return value; 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) static const u32 *cie_for_fde(const u32 *fde, const struct unwind_table *table)
{ {
const u32 *cie; 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))) if (!*fde || (*fde & (sizeof(*fde) - 1)))
return &bad_cie; return &bad_cie;
if (fde[1] == 0xffffffff) if (fde[1] == CIE_ID)
return &not_fde; /* this is a CIE */ return &not_fde; /* this is a CIE */
if ((fde[1] & (sizeof(*fde) - 1))) if ((fde[1] & (sizeof(*fde) - 1)))
/* || fde[1] > (unsigned long)(fde + 1) - (unsigned long)table->address) */ /* || fde[1] > (unsigned long)(fde + 1) - (unsigned long)table->address) */
return NULL; /* this is not a valid FDE */ return NULL; /* this is not a valid FDE */
/* cie = fde + 1 - fde[1] / sizeof(*fde); */ cie = __cie_for_fde(fde);
cie = (u32 *) fde[1];
if (*cie <= sizeof(*cie) + 4 || *cie >= fde[1] - sizeof(*fde) if (*cie <= sizeof(*cie) + 4 || *cie >= fde[1] - sizeof(*fde)
|| (*cie & (sizeof(*cie) - 1)) || (*cie & (sizeof(*cie) - 1))
|| (cie[1] != 0xffffffff)) || (cie[1] != CIE_ID))
return NULL; /* this is not a (valid) CIE */ return NULL; /* this is not a (valid) CIE */
return cie; return cie;
} }