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ARC: dw2 unwind: enable cfi pseudo ops in string lib
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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: Vineet Gupta <vgupta@synopsys.com>
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Vineet Gupta committed Sep 30, 2016
1 parent 5a205a3 commit 86effd0
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Showing 11 changed files with 26 additions and 25 deletions.
3 changes: 2 additions & 1 deletion arch/arc/kernel/ctx_sw_asm.S
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Original file line number Diff line number Diff line change
Expand Up @@ -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]
Expand Down Expand Up @@ -59,4 +60,4 @@ __switch_to:
ld.ab blink, [sp, 4]
j [blink]

END(__switch_to)
END_CFI(__switch_to)
4 changes: 2 additions & 2 deletions arch/arc/lib/memcmp.S
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Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand Down Expand Up @@ -149,4 +149,4 @@ ENTRY(memcmp)
.Lnil:
j_s.d [blink]
mov r0,0
END(memcmp)
END_CFI(memcmp)
4 changes: 2 additions & 2 deletions arch/arc/lib/memcpy-700.S
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Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand Down Expand Up @@ -63,4 +63,4 @@ ENTRY(memcpy)
.Lendbloop:
j_s.d [blink]
stb r12,[r5,0]
END(memcpy)
END_CFI(memcpy)
4 changes: 2 additions & 2 deletions arch/arc/lib/memcpy-archs.S
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Expand Up @@ -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
Expand Down Expand Up @@ -233,4 +233,4 @@ ENTRY(memcpy)
.Lcopybytewise_3:
j [blink]

END(memcpy)
END_CFI(memcpy)
8 changes: 4 additions & 4 deletions arch/arc/lib/memset-archs.S
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Expand Up @@ -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
Expand Down Expand Up @@ -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)
8 changes: 4 additions & 4 deletions arch/arc/lib/memset.S
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Expand Up @@ -10,7 +10,7 @@

#define SMALL 7 /* Must be at least 6 to deal with alignment/loop issues. */

ENTRY(memset)
ENTRY_CFI(memset)
mov_s r4,r0
or r12,r0,r2
bmsk.f r12,r12,1
Expand Down Expand Up @@ -46,14 +46,14 @@ ENTRY(memset)
stb.ab r1,[r4,1]
.Ltiny_end:
j_s [blink]
END(memset)
END_CFI(memset)

; memzero: @r0 = mem, @r1 = size_t
; memset: @r0 = mem, @r1 = char, @r2 = size_t

ENTRY(memzero)
ENTRY_CFI(memzero)
; adjust bzero args to memset args
mov r2, r1
mov r1, 0
b memset ;tail call so need to tinker with blink
END(memzero)
END_CFI(memzero)
4 changes: 2 additions & 2 deletions arch/arc/lib/strchr-700.S
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Expand Up @@ -13,7 +13,7 @@

#include <linux/linkage.h>

ENTRY(strchr)
ENTRY_CFI(strchr)
extb_s r1,r1
asl r5,r1,8
bmsk r2,r0,1
Expand Down Expand Up @@ -130,4 +130,4 @@ ENTRY(strchr)
j_s.d [blink]
mov.mi r0,0
#endif /* ENDIAN */
END(strchr)
END_CFI(strchr)
4 changes: 2 additions & 2 deletions arch/arc/lib/strcmp-archs.S
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Original file line number Diff line number Diff line change
Expand Up @@ -8,7 +8,7 @@

#include <linux/linkage.h>

ENTRY(strcmp)
ENTRY_CFI(strcmp)
or r2, r0, r1
bmsk_s r2, r2, 1
brne r2, 0, @.Lcharloop
Expand Down Expand Up @@ -75,4 +75,4 @@ ENTRY(strcmp)
.Lcmpend:
j_s.d [blink]
sub r0, r2, r3
END(strcmp)
END_CFI(strcmp)
4 changes: 2 additions & 2 deletions arch/arc/lib/strcmp.S
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Original file line number Diff line number Diff line change
Expand Up @@ -15,7 +15,7 @@

#include <linux/linkage.h>

ENTRY(strcmp)
ENTRY_CFI(strcmp)
or r2,r0,r1
bmsk_s r2,r2,1
brne r2,0,.Lcharloop
Expand Down Expand Up @@ -93,4 +93,4 @@ ENTRY(strcmp)
.Lcmpend:
j_s.d [blink]
sub r0,r2,r3
END(strcmp)
END_CFI(strcmp)
4 changes: 2 additions & 2 deletions arch/arc/lib/strcpy-700.S
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Original file line number Diff line number Diff line change
Expand Up @@ -18,7 +18,7 @@

#include <linux/linkage.h>

ENTRY(strcpy)
ENTRY_CFI(strcpy)
or r2,r0,r1
bmsk_s r2,r2,1
brne.d r2,0,charloop
Expand Down Expand Up @@ -67,4 +67,4 @@ charloop:
brne.d r3,0,charloop
stb.ab r3,[r10,1]
j [blink]
END(strcpy)
END_CFI(strcpy)
4 changes: 2 additions & 2 deletions arch/arc/lib/strlen.S
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Original file line number Diff line number Diff line change
Expand Up @@ -8,7 +8,7 @@

#include <linux/linkage.h>

ENTRY(strlen)
ENTRY_CFI(strlen)
or r3,r0,7
ld r2,[r3,-7]
ld.a r6,[r3,-3]
Expand Down Expand Up @@ -80,4 +80,4 @@ ENTRY(strlen)
.Learly_end:
b.d .Lend
sub_s.ne r1,r1,r1
END(strlen)
END_CFI(strlen)

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