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Commit d040876b authored by Vineet Gupta's avatar Vineet Gupta
Browse files

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



This paves way for switching to .eh_frame based unwindiing

Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
parent 94f4fb08

arch/arc/kernel/unwind.c

+18 −7
Original line number Diff line number Diff line
@@ -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;

}