Commit 86effd0d authored by Vineet Gupta's avatar Vineet Gupta
Browse files

ARC: dw2 unwind: enable cfi pseudo ops in string lib 



This uses a new set of annoations viz. ENTRY_CFI/END_CFI to enabel cfi
ops generation.

Note that we didn't change the normal ENTRY/EXIT as we don't actually
want unwind info in the trap/exception/interrutp handlers which use
these, as unwinder then gets confused (it keeps recursing vs. stopping).
Semantically these are leaf routines and unwinding should stop when it
hits those routines.

Before
------

    28.52%     1.19%          9929  hackbench  libuClibc-1.0.17.so   [.] __write_nocancel
            |
            ---__write_nocancel
               |--8.95%--EV_Trap
               |           --8.25%--sys_write
               |                     |--3.93%--sock_write_iter
     ...
               |--2.62%--memset   <==== [LEAF entry as no unwind info]
                         ^^^^^^

After
-----

    29.46%     1.24%         13622  hackbench  libuClibc-1.0.17.so   [.] __write_nocancel
            |
            ---__write_nocancel
               |--9.31%--EV_Trap
               |           --8.62%--sys_write
               |                     |--4.17%--sock_write_iter
     ...
               |--6.19%--sys_write
               |           --6.19%--sock_write_iter
               |                     unix_stream_sendmsg
               |                     |--1.62%--sock_alloc_send_pskb
               |                     |--0.89%--sock_def_readable
               |                     |--0.88%--_raw_spin_unlock_irqrestore
               |                     |--0.69%--memset
               |                     |         ^^^^^^     <==== [now in proper callframe]
               |                     |
               |                      --0.52%--skb_copy_datagram_from_iter

Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
parent 5a205a32

arch/arc/kernel/ctx_sw_asm.S

+2 −1
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ 
	.global __switch_to

	.type   __switch_to, @function

__switch_to:

	CFI_STARTPROC



	/* Save regs on kernel mode stack of task */

	st.a    blink, [sp, -4]
@@ -59,4 +60,4 @@ __switch_to: 
	ld.ab   blink, [sp, 4]

	j       [blink]



END(__switch_to)
 
END_CFI(__switch_to)

arch/arc/lib/memcmp.S

+2 −2
Original line number Diff line number Diff line
@@ -16,7 +16,7 @@ 
#define SHIFT r2

#endif



ENTRY(memcmp)

ENTRY_CFI(memcmp)

	or	r12,r0,r1

	asl_s	r12,r12,30

	sub	r3,r2,1
@@ -149,4 +149,4 @@ ENTRY(memcmp) 
.Lnil:

	j_s.d	[blink]

	mov	r0,0

END(memcmp)
 
END_CFI(memcmp)

arch/arc/lib/memcpy-700.S

+2 −2
Original line number Diff line number Diff line
@@ -8,7 +8,7 @@ 


#include <linux/linkage.h>



ENTRY(memcpy)

ENTRY_CFI(memcpy)

	or	r3,r0,r1

	asl_s	r3,r3,30

	mov_s	r5,r0
@@ -63,4 +63,4 @@ ENTRY(memcpy) 
.Lendbloop:

	j_s.d	[blink]

	stb	r12,[r5,0]

END(memcpy)
 
END_CFI(memcpy)

arch/arc/lib/memcpy-archs.S

+2 −2
Original line number Diff line number Diff line
@@ -40,7 +40,7 @@ 
# define ZOLAND			0xF

#endif



ENTRY(memcpy)

ENTRY_CFI(memcpy)

	prefetch [r1]		; Prefetch the read location

	prefetchw [r0]		; Prefetch the write location

	mov.f	0, r2
@@ -233,4 +233,4 @@ ENTRY(memcpy) 
.Lcopybytewise_3:

	j	[blink]



END(memcpy)
 
END_CFI(memcpy)

arch/arc/lib/memset-archs.S

+4 −4
Original line number Diff line number Diff line
@@ -10,7 +10,7 @@ 


#undef PREALLOC_NOT_AVAIL



ENTRY(memset)

ENTRY_CFI(memset)

	prefetchw [r0]		; Prefetch the write location

	mov.f	0, r2

;;; if size is zero
@@ -112,11 +112,11 @@ ENTRY(memset) 


	j	[blink]



END(memset)

END_CFI(memset)



ENTRY(memzero)

ENTRY_CFI(memzero)

    ; adjust bzero args to memset args

    mov r2, r1

    b.d  memset    ;tail call so need to tinker with blink

    mov r1, 0

END(memzero)
 
END_CFI(memzero)

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