tjh.dev / kernel
Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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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: Vineet Gupta <vgupta@synopsys.com>

Vineet Gupta 86effd0d 5a205a32

+26 -25
+2 -1
arch/arc/kernel/ctx_sw_asm.S
··· 23 23 .global __switch_to 24 24 .type __switch_to, @function 25 25 __switch_to: 26 + CFI_STARTPROC 26 27 27 28 /* Save regs on kernel mode stack of task */ 28 29 st.a blink, [sp, -4] ··· 60 59 ld.ab blink, [sp, 4] 61 60 j [blink] 62 61 63 - END(__switch_to) 62 + END_CFI(__switch_to)
+2 -2
arch/arc/lib/memcmp.S
··· 16 16 #define SHIFT r2 17 17 #endif 18 18 19 - ENTRY(memcmp) 19 + ENTRY_CFI(memcmp) 20 20 or r12,r0,r1 21 21 asl_s r12,r12,30 22 22 sub r3,r2,1 ··· 149 149 .Lnil: 150 150 j_s.d [blink] 151 151 mov r0,0 152 - END(memcmp) 152 + END_CFI(memcmp)
+2 -2
arch/arc/lib/memcpy-700.S
··· 8 8 9 9 #include <linux/linkage.h> 10 10 11 - ENTRY(memcpy) 11 + ENTRY_CFI(memcpy) 12 12 or r3,r0,r1 13 13 asl_s r3,r3,30 14 14 mov_s r5,r0 ··· 63 63 .Lendbloop: 64 64 j_s.d [blink] 65 65 stb r12,[r5,0] 66 - END(memcpy) 66 + END_CFI(memcpy)
+2 -2
arch/arc/lib/memcpy-archs.S
··· 40 40 # define ZOLAND 0xF 41 41 #endif 42 42 43 - ENTRY(memcpy) 43 + ENTRY_CFI(memcpy) 44 44 prefetch [r1] ; Prefetch the read location 45 45 prefetchw [r0] ; Prefetch the write location 46 46 mov.f 0, r2 ··· 233 233 .Lcopybytewise_3: 234 234 j [blink] 235 235 236 - END(memcpy) 236 + END_CFI(memcpy)
+4 -4
arch/arc/lib/memset-archs.S
··· 10 10 11 11 #undef PREALLOC_NOT_AVAIL 12 12 13 - ENTRY(memset) 13 + ENTRY_CFI(memset) 14 14 prefetchw [r0] ; Prefetch the write location 15 15 mov.f 0, r2 16 16 ;;; if size is zero ··· 112 112 113 113 j [blink] 114 114 115 - END(memset) 115 + END_CFI(memset) 116 116 117 - ENTRY(memzero) 117 + ENTRY_CFI(memzero) 118 118 ; adjust bzero args to memset args 119 119 mov r2, r1 120 120 b.d memset ;tail call so need to tinker with blink 121 121 mov r1, 0 122 - END(memzero) 122 + END_CFI(memzero)
+4 -4
arch/arc/lib/memset.S
··· 10 10 11 11 #define SMALL 7 /* Must be at least 6 to deal with alignment/loop issues. */ 12 12 13 - ENTRY(memset) 13 + ENTRY_CFI(memset) 14 14 mov_s r4,r0 15 15 or r12,r0,r2 16 16 bmsk.f r12,r12,1 ··· 46 46 stb.ab r1,[r4,1] 47 47 .Ltiny_end: 48 48 j_s [blink] 49 - END(memset) 49 + END_CFI(memset) 50 50 51 51 ; memzero: @r0 = mem, @r1 = size_t 52 52 ; memset: @r0 = mem, @r1 = char, @r2 = size_t 53 53 54 - ENTRY(memzero) 54 + ENTRY_CFI(memzero) 55 55 ; adjust bzero args to memset args 56 56 mov r2, r1 57 57 mov r1, 0 58 58 b memset ;tail call so need to tinker with blink 59 - END(memzero) 59 + END_CFI(memzero)
+2 -2
arch/arc/lib/strchr-700.S
··· 13 13 14 14 #include <linux/linkage.h> 15 15 16 - ENTRY(strchr) 16 + ENTRY_CFI(strchr) 17 17 extb_s r1,r1 18 18 asl r5,r1,8 19 19 bmsk r2,r0,1 ··· 130 130 j_s.d [blink] 131 131 mov.mi r0,0 132 132 #endif /* ENDIAN */ 133 - END(strchr) 133 + END_CFI(strchr)
+2 -2
arch/arc/lib/strcmp-archs.S
··· 8 8 9 9 #include <linux/linkage.h> 10 10 11 - ENTRY(strcmp) 11 + ENTRY_CFI(strcmp) 12 12 or r2, r0, r1 13 13 bmsk_s r2, r2, 1 14 14 brne r2, 0, @.Lcharloop ··· 75 75 .Lcmpend: 76 76 j_s.d [blink] 77 77 sub r0, r2, r3 78 - END(strcmp) 78 + END_CFI(strcmp)
+2 -2
arch/arc/lib/strcmp.S
··· 15 15 16 16 #include <linux/linkage.h> 17 17 18 - ENTRY(strcmp) 18 + ENTRY_CFI(strcmp) 19 19 or r2,r0,r1 20 20 bmsk_s r2,r2,1 21 21 brne r2,0,.Lcharloop ··· 93 93 .Lcmpend: 94 94 j_s.d [blink] 95 95 sub r0,r2,r3 96 - END(strcmp) 96 + END_CFI(strcmp)
+2 -2
arch/arc/lib/strcpy-700.S
··· 18 18 19 19 #include <linux/linkage.h> 20 20 21 - ENTRY(strcpy) 21 + ENTRY_CFI(strcpy) 22 22 or r2,r0,r1 23 23 bmsk_s r2,r2,1 24 24 brne.d r2,0,charloop ··· 67 67 brne.d r3,0,charloop 68 68 stb.ab r3,[r10,1] 69 69 j [blink] 70 - END(strcpy) 70 + END_CFI(strcpy)
+2 -2
arch/arc/lib/strlen.S
··· 8 8 9 9 #include <linux/linkage.h> 10 10 11 - ENTRY(strlen) 11 + ENTRY_CFI(strlen) 12 12 or r3,r0,7 13 13 ld r2,[r3,-7] 14 14 ld.a r6,[r3,-3] ··· 80 80 .Learly_end: 81 81 b.d .Lend 82 82 sub_s.ne r1,r1,r1 83 - END(strlen) 83 + END_CFI(strlen)