Re: remove the last set_fs() in common code, and remove it for x86 and powerpc v2

Christophe Leroy
2020-09-01T18:40:30Z

Le 01/09/2020 à 19:25, Al Viro a écrit :
> On Tue, Sep 01, 2020 at 07:13:00PM +0200, Christophe Leroy wrote:
>
>> 10.92% dd [kernel.kallsyms] [k] iov_iter_zero
>
> Interesting... Could you get an instruction-level profile inside iov_iter_zero(),
> along with the disassembly of that sucker?
>

Output of perf annotate:

Percent | Source code & Disassembly of vmlinux for cpu-clock (3579
samples)
---------------------------------------------------------------------------------
:
:
:
: Disassembly of section .text:
:
: c02cb3a4 <iov_iter_zero>:
: iov_iter_zero():
2.24 : c02cb3a4: stwu r1,-80(r1)
0.31 : c02cb3a8: stw r30,72(r1)
0.00 : c02cb3ac: mr r30,r4
0.11 : c02cb3b0: stw r31,76(r1)
0.00 : c02cb3b4: mr r31,r3
1.06 : c02cb3b8: stw r27,60(r1)
: iov_iter_type():
0.03 : c02cb3bc: lwz r10,0(r4)
0.06 : c02cb3c0: rlwinm r9,r10,0,0,30
: iov_iter_zero():
0.03 : c02cb3c4: cmpwi r9,32
0.00 : c02cb3c8: lwz r9,624(r2)
2.15 : c02cb3cc: stw r9,28(r1)
0.00 : c02cb3d0: li r9,0
0.00 : c02cb3d4: beq c02cb520 <iov_iter_zero+0x17c>
0.14 : c02cb3d8: lwz r9,8(r4)
0.08 : c02cb3dc: cmplw r9,r3
0.00 : c02cb3e0: mr r27,r9
0.03 : c02cb3e4: bgt c02cb4fc <iov_iter_zero+0x158>
1.34 : c02cb3e8: cmpwi r9,0
0.00 : c02cb3ec: beq c02cb4d0 <iov_iter_zero+0x12c>
0.11 : c02cb3f0: andi. r8,r10,16
0.17 : c02cb3f4: lwz r31,4(r30)
1.79 : c02cb3f8: bne c02cb61c <iov_iter_zero+0x278>
0.00 : c02cb3fc: andi. r8,r10,8
0.06 : c02cb400: bne c02cb770 <iov_iter_zero+0x3cc>
0.22 : c02cb404: andi. r10,r10,64
0.03 : c02cb408: bne c02cb88c <iov_iter_zero+0x4e8>
0.11 : c02cb40c: stw r29,68(r1)
1.59 : c02cb410: stw r28,64(r1)
0.03 : c02cb414: lwz r28,12(r30)
0.00 : c02cb418: lwz r7,4(r28)
1.87 : c02cb41c: subf r29,r31,r7
0.28 : c02cb420: cmplw r29,r27
0.03 : c02cb424: bgt c02cb50c <iov_iter_zero+0x168>
0.03 : c02cb428: cmpwi r29,0
0.00 : c02cb42c: beq c02cb898 <iov_iter_zero+0x4f4>
1.34 : c02cb430: lwz r3,0(r28)
: __access_ok():
0.00 : c02cb434: lis r10,-16384
: iov_iter_zero():
0.36 : c02cb438: add r3,r3,r31
: __access_ok():
0.03 : c02cb43c: cmplw r3,r10
1.79 : c02cb440: bge c02cb514 <iov_iter_zero+0x170>
13.19 : c02cb444: subf r10,r3,r10
: clear_user():
0.00 : c02cb448: cmplw r29,r10
4.41 : c02cb44c: mflr r0
0.00 : c02cb450: stw r0,84(r1)
0.00 : c02cb454: bgt c02cb8c4 <iov_iter_zero+0x520>
0.00 : c02cb458: mr r4,r29
0.00 : c02cb45c: bl c001a41c <__arch_clear_user>
: iov_iter_zero():
0.70 : c02cb460: add r31,r31,r29
0.00 : c02cb464: cmpwi r3,0
17.13 : c02cb468: subf r29,r29,r27
0.00 : c02cb46c: subf r31,r3,r31
1.20 : c02cb470: add r29,r29,r3
0.00 : c02cb474: beq c02cb8b8 <iov_iter_zero+0x514>
0.00 : c02cb478: lwz r9,8(r30)
0.00 : c02cb47c: subf r10,r27,r29
0.00 : c02cb480: lwz r0,84(r1)
0.00 : c02cb484: subf r27,r29,r27
0.00 : c02cb488: add r9,r10,r9
0.00 : c02cb48c: lwz r7,4(r28)
0.00 : c02cb490: lwz r10,12(r30)
0.00 : c02cb494: mtlr r0
1.65 : c02cb498: cmplw r31,r7
14.61 : c02cb49c: bne c02cb4a8 <iov_iter_zero+0x104>
1.65 : c02cb4a0: addi r28,r28,8
0.00 : c02cb4a4: li r31,0
14.92 : c02cb4a8: lwz r8,16(r30)
0.00 : c02cb4ac: subf r10,r10,r28
1.12 : c02cb4b0: srawi r10,r10,3
0.56 : c02cb4b4: stw r28,12(r30)
0.00 : c02cb4b8: subf r10,r10,r8
1.23 : c02cb4bc: stw r10,16(r30)
0.00 : c02cb4c0: lwz r28,64(r1)
0.56 : c02cb4c4: lwz r29,68(r1)
0.00 : c02cb4c8: stw r9,8(r30)
2.12 : c02cb4cc: stw r31,4(r30)
0.00 : c02cb4d0: lwz r9,28(r1)
0.61 : c02cb4d4: lwz r10,624(r2)
0.00 : c02cb4d8: xor. r9,r9,r10
0.00 : c02cb4dc: li r10,0
0.00 : c02cb4e0: bne c02cb9a8 <iov_iter_zero+0x604>
0.00 : c02cb4e4: mr r3,r27
0.00 : c02cb4e8: lwz r30,72(r1)
1.73 : c02cb4ec: lwz r27,60(r1)
0.50 : c02cb4f0: lwz r31,76(r1)
0.00 : c02cb4f4: addi r1,r1,80
0.00 : c02cb4f8: blr
0.00 : c02cb4fc: cmpwi r9,0
0.00 : c02cb500: mr r27,r3
0.00 : c02cb504: beq c02cb4d0 <iov_iter_zero+0x12c>
0.00 : c02cb508: b c02cb3f0 <iov_iter_zero+0x4c>
0.00 : c02cb50c: mr r29,r27
0.00 : c02cb510: b c02cb428 <iov_iter_zero+0x84>
: __access_ok():
0.00 : c02cb514: li r27,0
0.00 : c02cb518: mr r10,r28
0.00 : c02cb51c: b c02cb498 <iov_iter_zero+0xf4>
: pipe_zero():
0.00 : c02cb520: mflr r0
0.00 : c02cb524: stw r26,56(r1)
0.00 : c02cb528: stw r0,84(r1)
0.00 : c02cb52c: mr r3,r4
0.00 : c02cb530: stw r28,64(r1)
0.00 : c02cb534: lwz r28,12(r4)
0.00 : c02cb538: lwz r26,40(r28)
0.00 : c02cb53c: bl c02c8e48 <sanity>
0.00 : c02cb540: cmpwi r3,0
0.00 : c02cb544: bne c02cb560 <iov_iter_zero+0x1bc>
0.00 : c02cb548: lwz r0,84(r1)
0.00 : c02cb54c: li r27,0
0.00 : c02cb550: lwz r26,56(r1)
0.00 : c02cb554: lwz r28,64(r1)
0.00 : c02cb558: mtlr r0
0.00 : c02cb55c: b c02cb4d0 <iov_iter_zero+0x12c>
0.00 : c02cb560: mr r4,r31
0.00 : c02cb564: addi r6,r1,24
0.00 : c02cb568: addi r5,r1,20
0.00 : c02cb56c: mr r3,r30
0.00 : c02cb570: bl c02c9030 <push_pipe>
0.00 : c02cb574: mr. r27,r3
0.00 : c02cb578: beq c02cb548 <iov_iter_zero+0x1a4>
0.00 : c02cb57c: lwz r4,24(r1)
0.00 : c02cb580: addi r26,r26,-1
0.00 : c02cb584: lwz r9,20(r1)
0.00 : c02cb588: stw r25,52(r1)
0.00 : c02cb58c: li r25,0
0.00 : c02cb590: stw r29,68(r1)
0.00 : c02cb594: mr r29,r27
0.00 : c02cb598: subfic r31,r4,4096
0.00 : c02cb59c: cmplw r31,r29
0.00 : c02cb5a0: ble c02cb5a8 <iov_iter_zero+0x204>
0.00 : c02cb5a4: mr r31,r29
0.00 : c02cb5a8: and r9,r26,r9
0.00 : c02cb5ac: lwz r8,80(r28)
0.00 : c02cb5b0: rlwinm r10,r9,1,0,30
0.00 : c02cb5b4: add r9,r10,r9
0.00 : c02cb5b8: rlwinm r9,r9,3,0,28
0.00 : c02cb5bc: lwzx r3,r8,r9
0.00 : c02cb5c0: mr r5,r31
0.00 : c02cb5c4: bl c02c92ec <memzero_page>
0.00 : c02cb5c8: subf. r29,r31,r29
0.00 : c02cb5cc: lwz r9,20(r1)
0.00 : c02cb5d0: li r4,0
0.00 : c02cb5d4: lwz r10,24(r1)
0.00 : c02cb5d8: stw r9,16(r30)
0.00 : c02cb5dc: addi r9,r9,1
0.00 : c02cb5e0: add r10,r10,r31
0.00 : c02cb5e4: stw r9,20(r1)
0.00 : c02cb5e8: stw r10,4(r30)
0.00 : c02cb5ec: stw r25,24(r1)
0.00 : c02cb5f0: bne c02cb598 <iov_iter_zero+0x1f4>
0.00 : c02cb5f4: lwz r9,8(r30)
0.00 : c02cb5f8: subf r9,r27,r9
0.00 : c02cb5fc: stw r9,8(r30)
: iov_iter_zero():
0.00 : c02cb600: lwz r0,84(r1)
0.00 : c02cb604: lwz r25,52(r1)
0.00 : c02cb608: lwz r26,56(r1)
0.00 : c02cb60c: mtlr r0
0.00 : c02cb610: lwz r28,64(r1)
0.00 : c02cb614: lwz r29,68(r1)
0.00 : c02cb618: b c02cb4d0 <iov_iter_zero+0x12c>
0.00 : c02cb61c: stw r23,44(r1)
0.00 : c02cb620: cmpwi r27,0
0.00 : c02cb624: stw r28,64(r1)
0.00 : c02cb628: mr r23,r27
0.00 : c02cb62c: stw r24,48(r1)
0.00 : c02cb630: li r28,0
0.00 : c02cb634: lwz r24,12(r30)
0.00 : c02cb638: mr r8,r24
0.00 : c02cb63c: beq c02cb714 <iov_iter_zero+0x370>
0.00 : c02cb640: mflr r0
0.00 : c02cb644: stw r25,52(r1)
0.00 : c02cb648: stw r0,84(r1)
0.00 : c02cb64c: stw r26,56(r1)
0.00 : c02cb650: stw r29,68(r1)
0.00 : c02cb654: rlwinm r25,r28,1,0,30
0.00 : c02cb658: add r25,r25,r28
0.00 : c02cb65c: rlwinm r25,r25,2,0,29
0.00 : c02cb660: add r10,r8,r25
0.00 : c02cb664: lwz r26,4(r10)
0.00 : c02cb668: mr r29,r25
0.00 : c02cb66c: lwz r9,8(r10)
0.00 : c02cb670: subf r26,r31,r26
0.00 : c02cb674: cmplw r26,r23
0.00 : c02cb678: add r9,r31,r9
0.00 : c02cb67c: clrlwi r4,r9,20
0.00 : c02cb680: ble c02cb688 <iov_iter_zero+0x2e4>
0.00 : c02cb684: mr r26,r23
0.00 : c02cb688: subfic r7,r4,4096
0.00 : c02cb68c: cmplw r26,r7
0.00 : c02cb690: ble c02cb698 <iov_iter_zero+0x2f4>
0.00 : c02cb694: mr r26,r7
0.00 : c02cb698: cmpwi r26,0
0.00 : c02cb69c: beq c02cb6c0 <iov_iter_zero+0x31c>
0.00 : c02cb6a0: lwz r3,0(r10)
0.00 : c02cb6a4: rlwinm r9,r9,25,7,26
0.00 : c02cb6a8: mr r5,r26
0.00 : c02cb6ac: add r3,r3,r9
0.00 : c02cb6b0: bl c02c92ec <memzero_page>
: bvec_iter_advance():
0.00 : c02cb6b4: cmplw r23,r26
: iov_iter_zero():
0.00 : c02cb6b8: lwz r8,12(r30)
: bvec_iter_advance():
0.00 : c02cb6bc: blt c02cb850 <iov_iter_zero+0x4ac>
0.00 : c02cb6c0: add. r31,r31,r26
0.00 : c02cb6c4: subf r23,r26,r23
0.00 : c02cb6c8: addi r10,r8,4
0.00 : c02cb6cc: bne c02cb6e4 <iov_iter_zero+0x340>
0.00 : c02cb6d0: b c02cb6f0 <iov_iter_zero+0x34c>
0.00 : c02cb6d4: subf. r31,r9,r31
0.00 : c02cb6d8: addi r28,r28,1
0.00 : c02cb6dc: addi r29,r29,12
0.00 : c02cb6e0: beq c02cb760 <iov_iter_zero+0x3bc>
0.00 : c02cb6e4: lwzx r9,r10,r29
0.00 : c02cb6e8: cmplw r31,r9
0.00 : c02cb6ec: bge c02cb6d4 <iov_iter_zero+0x330>
: iov_iter_zero():
0.00 : c02cb6f0: cmpwi r23,0
0.00 : c02cb6f4: bne c02cb654 <iov_iter_zero+0x2b0>
0.00 : c02cb6f8: add r8,r8,r29
0.00 : c02cb6fc: lwz r0,84(r1)
0.00 : c02cb700: lwz r9,8(r30)
0.00 : c02cb704: lwz r25,52(r1)
0.00 : c02cb708: mtlr r0
0.00 : c02cb70c: lwz r26,56(r1)
0.00 : c02cb710: lwz r29,68(r1)
0.00 : c02cb714: subf r24,r24,r8
0.00 : c02cb718: stw r8,12(r30)
0.00 : c02cb71c: srawi r6,r24,2
0.00 : c02cb720: lwz r7,16(r30)
0.00 : c02cb724: rlwinm r10,r24,0,0,29
0.00 : c02cb728: add r10,r10,r6
0.00 : c02cb72c: rlwinm r8,r10,4,0,27
0.00 : c02cb730: add r10,r10,r8
0.00 : c02cb734: rlwinm r8,r10,8,0,23
0.00 : c02cb738: add r10,r10,r8
0.00 : c02cb73c: rlwinm r8,r10,16,0,15
0.00 : c02cb740: add r10,r10,r8
0.00 : c02cb744: add r10,r7,r10
0.00 : c02cb748: stw r10,16(r30)
0.00 : c02cb74c: subf r9,r27,r9
0.00 : c02cb750: lwz r23,44(r1)
0.00 : c02cb754: lwz r24,48(r1)
0.00 : c02cb758: lwz r28,64(r1)
0.00 : c02cb75c: b c02cb4c8 <iov_iter_zero+0x124>
0.00 : c02cb760: rlwinm r29,r28,1,0,30
0.00 : c02cb764: add r29,r29,r28
0.00 : c02cb768: rlwinm r29,r29,2,0,29
0.00 : c02cb76c: b c02cb6f0 <iov_iter_zero+0x34c>
0.00 : c02cb770: mflr r0
0.00 : c02cb774: stw r26,56(r1)
0.00 : c02cb778: stw r0,84(r1)
0.00 : c02cb77c: stw r28,64(r1)
0.00 : c02cb780: stw r29,68(r1)
0.00 : c02cb784: lwz r28,12(r30)
0.00 : c02cb788: lwz r29,4(r28)
0.00 : c02cb78c: subf r29,r31,r29
0.00 : c02cb790: cmplw r29,r27
0.00 : c02cb794: ble c02cb79c <iov_iter_zero+0x3f8>
0.00 : c02cb798: mr r29,r27
0.00 : c02cb79c: cmpwi r29,0
0.00 : c02cb7a0: beq c02cb8d8 <iov_iter_zero+0x534>
0.00 : c02cb7a4: lwz r3,0(r28)
0.00 : c02cb7a8: mr r5,r29
0.00 : c02cb7ac: li r4,0
0.00 : c02cb7b0: add r3,r3,r31
0.00 : c02cb7b4: subf r26,r29,r27
0.00 : c02cb7b8: bl c001999c <memset>
0.00 : c02cb7bc: add r31,r31,r29
0.00 : c02cb7c0: cmpwi r26,0
0.00 : c02cb7c4: bne c02cb818 <iov_iter_zero+0x474>
0.00 : c02cb7c8: lwz r9,4(r28)
0.00 : c02cb7cc: cmpw r9,r31
0.00 : c02cb7d0: bne c02cb7dc <iov_iter_zero+0x438>
0.00 : c02cb7d4: addi r28,r28,8
0.00 : c02cb7d8: li r31,0
0.00 : c02cb7dc: lwz r9,12(r30)
0.00 : c02cb7e0: lwz r8,16(r30)
0.00 : c02cb7e4: subf r10,r9,r28
0.00 : c02cb7e8: stw r28,12(r30)
0.00 : c02cb7ec: srawi r10,r10,3
0.00 : c02cb7f0: lwz r9,8(r30)
0.00 : c02cb7f4: subf r10,r10,r8
0.00 : c02cb7f8: stw r10,16(r30)
0.00 : c02cb7fc: subf r9,r27,r9
0.00 : c02cb800: lwz r0,84(r1)
0.00 : c02cb804: lwz r26,56(r1)
0.00 : c02cb808: lwz r28,64(r1)
0.00 : c02cb80c: mtlr r0
0.00 : c02cb810: lwz r29,68(r1)
0.00 : c02cb814: b c02cb4c8 <iov_iter_zero+0x124>
0.00 : c02cb818: lwz r31,12(r28)
0.00 : c02cb81c: addi r28,r28,8
0.00 : c02cb820: cmplw r31,r26
0.00 : c02cb824: ble c02cb82c <iov_iter_zero+0x488>
0.00 : c02cb828: mr r31,r26
0.00 : c02cb82c: cmpwi r31,0
0.00 : c02cb830: beq c02cb818 <iov_iter_zero+0x474>
0.00 : c02cb834: lwz r3,0(r28)
0.00 : c02cb838: mr r5,r31
0.00 : c02cb83c: li r4,0
0.00 : c02cb840: bl c001999c <memset>
0.00 : c02cb844: subf. r26,r31,r26
0.00 : c02cb848: beq c02cb7c8 <iov_iter_zero+0x424>
0.00 : c02cb84c: b c02cb818 <iov_iter_zero+0x474>
: bvec_iter_advance():
0.00 : c02cb850: lis r9,-16236
0.00 : c02cb854: lbz r10,-20170(r9)
0.00 : c02cb858: cmpwi r10,0
0.00 : c02cb85c: beq c02cb868 <iov_iter_zero+0x4c4>
: iov_iter_zero():
0.00 : c02cb860: add r8,r8,r25
0.00 : c02cb864: b c02cb6fc <iov_iter_zero+0x358>
: bvec_iter_advance():
0.00 : c02cb868: lis r3,-16253
0.00 : c02cb86c: li r10,1
0.00 : c02cb870: addi r3,r3,7580
0.00 : c02cb874: stb r10,-20170(r9)
0.00 : c02cb878: bl c0029b1c <__warn_printk>
0.00 : c02cb87c: twui r0,0
: iov_iter_zero():
0.00 : c02cb880: lwz r8,12(r30)
0.00 : c02cb884: add r8,r8,r25
0.00 : c02cb888: b c02cb6fc <iov_iter_zero+0x358>
0.00 : c02cb88c: add r31,r31,r27
0.00 : c02cb890: subf r9,r27,r9
0.00 : c02cb894: b c02cb4c8 <iov_iter_zero+0x124>
0.00 : c02cb898: mr r29,r27
0.00 : c02cb89c: cmpwi r29,0
1.65 : c02cb8a0: bne c02cb8e0 <iov_iter_zero+0x53c>
0.00 : c02cb8a4: lwz r9,8(r30)
0.53 : c02cb8a8: lwz r7,4(r28)
0.00 : c02cb8ac: lwz r10,12(r30)
0.00 : c02cb8b0: subf r9,r27,r9
0.00 : c02cb8b4: b c02cb498 <iov_iter_zero+0xf4>
0.25 : c02cb8b8: lwz r0,84(r1)
2.26 : c02cb8bc: mtlr r0
0.00 : c02cb8c0: b c02cb89c <iov_iter_zero+0x4f8>
: clear_user():
0.00 : c02cb8c4: lwz r0,84(r1)
0.00 : c02cb8c8: li r27,0
0.00 : c02cb8cc: mr r10,r28
0.00 : c02cb8d0: mtlr r0
0.00 : c02cb8d4: b c02cb498 <iov_iter_zero+0xf4>
: iov_iter_zero():
0.00 : c02cb8d8: mr r26,r27
0.00 : c02cb8dc: b c02cb7c0 <iov_iter_zero+0x41c>
0.00 : c02cb8e0: stw r26,56(r1)
0.00 : c02cb8e4: stw r25,52(r1)
: __access_ok():
0.00 : c02cb8e8: lis r25,-16384
: iov_iter_zero():
0.00 : c02cb8ec: lwz r7,12(r28)
0.00 : c02cb8f0: addi r26,r28,8
0.00 : c02cb8f4: mr r31,r29
0.00 : c02cb8f8: cmplw r29,r7
0.00 : c02cb8fc: ble c02cb904 <iov_iter_zero+0x560>
0.00 : c02cb900: mr r31,r7
0.00 : c02cb904: cmpwi r31,0
0.00 : c02cb908: beq c02cba04 <iov_iter_zero+0x660>
0.00 : c02cb90c: lwz r3,0(r26)
: __access_ok():
0.00 : c02cb910: cmplw r3,r25
0.00 : c02cb914: bge c02cb980 <iov_iter_zero+0x5dc>
0.00 : c02cb918: subf r9,r3,r25
: clear_user():
0.00 : c02cb91c: cmplw r31,r9
0.00 : c02cb920: mflr r0
0.00 : c02cb924: stw r0,84(r1)
0.00 : c02cb928: bgt c02cb978 <iov_iter_zero+0x5d4>
0.00 : c02cb92c: mr r4,r31
0.00 : c02cb930: bl c001a41c <__arch_clear_user>
: iov_iter_zero():
0.00 : c02cb934: subf r29,r31,r29
0.00 : c02cb938: cmpwi r3,0
0.00 : c02cb93c: subf r31,r3,r31
0.00 : c02cb940: add r29,r3,r29
0.00 : c02cb944: beq c02cb9cc <iov_iter_zero+0x628>
0.00 : c02cb948: lwz r9,8(r30)
0.00 : c02cb94c: subf r8,r27,r29
0.00 : c02cb950: lwz r0,84(r1)
0.00 : c02cb954: subf r27,r29,r27
0.00 : c02cb958: lwz r7,12(r28)
0.00 : c02cb95c: add r9,r8,r9
0.00 : c02cb960: mr r28,r26
0.00 : c02cb964: lwz r10,12(r30)
0.00 : c02cb968: lwz r25,52(r1)
0.00 : c02cb96c: mtlr r0
0.00 : c02cb970: lwz r26,56(r1)
0.00 : c02cb974: b c02cb498 <iov_iter_zero+0xf4>
0.00 : c02cb978: lwz r0,84(r1)
0.00 : c02cb97c: mtlr r0
0.00 : c02cb980: lwz r9,8(r30)
0.00 : c02cb984: subf r8,r27,r29
0.00 : c02cb988: mr r28,r26
0.00 : c02cb98c: lwz r10,12(r30)
0.00 : c02cb990: lwz r25,52(r1)
0.00 : c02cb994: add r9,r8,r9
0.00 : c02cb998: lwz r26,56(r1)
0.00 : c02cb99c: subf r27,r29,r27
0.00 : c02cb9a0: li r31,0
0.00 : c02cb9a4: b c02cb498 <iov_iter_zero+0xf4>
0.00 : c02cb9a8: mflr r0
0.00 : c02cb9ac: stw r23,44(r1)
0.00 : c02cb9b0: stw r0,84(r1)
0.00 : c02cb9b4: stw r24,48(r1)
0.00 : c02cb9b8: stw r25,52(r1)
0.00 : c02cb9bc: stw r26,56(r1)
0.00 : c02cb9c0: stw r28,64(r1)
0.00 : c02cb9c4: stw r29,68(r1)
0.00 : c02cb9c8: bl c071db48 <__stack_chk_fail>
0.00 : c02cb9cc: cmpwi r29,0
0.00 : c02cb9d0: bne c02cb9fc <iov_iter_zero+0x658>
0.00 : c02cb9d4: lwz r9,8(r30)
0.00 : c02cb9d8: lwz r0,84(r1)
0.00 : c02cb9dc: lwz r7,12(r28)
0.00 : c02cb9e0: subf r9,r27,r9
0.00 : c02cb9e4: mr r28,r26
0.00 : c02cb9e8: lwz r10,12(r30)
0.00 : c02cb9ec: lwz r25,52(r1)
0.00 : c02cb9f0: mtlr r0
0.00 : c02cb9f4: lwz r26,56(r1)
0.00 : c02cb9f8: b c02cb498 <iov_iter_zero+0xf4>
0.00 : c02cb9fc: lwz r0,84(r1)
0.00 : c02cba00: mtlr r0
0.00 : c02cba04: mr r28,r26
0.00 : c02cba08: b c02cb8ec <iov_iter_zero+0x548>

Christophe