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Commit b0f55f2a authored by Joern Rennecke's avatar Joern Rennecke Committed by Linus Torvalds
Browse files

ARC: [lib] strchr breakage in Big-endian configuration 



For a search buffer, 2 byte aligned, strchr() was returning pointer
outside of buffer (buf - 1)

------------->8----------------
    // Input buffer (default 4 byte aigned)
    char *buffer = "1AA_";

    // actual search start (to mimick 2 byte alignment)
    char *current_line = &(buffer[2]);

    // Character to search for
    char c = 'A';

    char *c_pos = strchr(current_line, c);

    printf("%s\n", c_pos) --> 'AA_' as oppose to 'A_'
------------->8----------------

Reported-by: default avatarAnton Kolesov <Anton.Kolesov@synopsys.com>
Debugged-by: default avatarAnton Kolesov <Anton.Kolesov@synopsys.com>
Cc: <stable@vger.kernel.org> # [3.9 and 3.10]
Cc: Noam Camus <noamc@ezchip.com>
Signed-off-by: default avatarJoern Rennecke <joern.rennecke@embecosm.com>
Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 89b53e50

arch/arc/lib/strchr-700.S

+10 −0
Original line number Original line Diff line number Diff line
@@ -39,9 +39,18 @@ ARC_ENTRY strchr 
	ld.a	r2,[r0,4]

	ld.a	r2,[r0,4]

	sub	r12,r6,r7

	sub	r12,r6,r7

	bic	r12,r12,r6

	bic	r12,r12,r6

#ifdef __LITTLE_ENDIAN__

	and	r7,r12,r4

	and	r7,r12,r4

	breq	r7,0,.Loop ; For speed, we want this branch to be unaligned.

	breq	r7,0,.Loop ; For speed, we want this branch to be unaligned.

	b	.Lfound_char ; Likewise this one.

	b	.Lfound_char ; Likewise this one.

#else

	and	r12,r12,r4

	breq	r12,0,.Loop ; For speed, we want this branch to be unaligned.

	lsr_s	r12,r12,7

	bic 	r2,r7,r6

	b.d	.Lfound_char_b

	and_s	r2,r2,r12

#endif

; /* We require this code address to be unaligned for speed...  */

; /* We require this code address to be unaligned for speed...  */

.Laligned:

.Laligned:

	ld_s	r2,[r0]

	ld_s	r2,[r0]
@@ -95,6 +104,7 @@ ARC_ENTRY strchr 
	lsr	r7,r7,7

	lsr	r7,r7,7





	bic	r2,r7,r6

	bic	r2,r7,r6

.Lfound_char_b:

	norm	r2,r2

	norm	r2,r2

	sub_s	r0,r0,4

	sub_s	r0,r0,4

	asr_s	r2,r2,3

	asr_s	r2,r2,3