linux-stable.git/arch/powerpc/include/asm/processor.h, branch v5.16.2 Linux kernel stable tree sched: Add wrapper for get_wchan() to keep task blocked 2021-10-15T09:25:14+00:00 Kees Cook keescook@chromium.org 2021-09-29T22:02:14+00:00 42a20f86dc19f9282d974df0ba4d226c865ab9dd Having a stable wchan means the process must be blocked and for it to stay that way while performing stack unwinding. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> [arm] Tested-by: Mark Rutland <mark.rutland@arm.com> [arm64] Link: https://lkml.kernel.org/r/20211008111626.332092234@infradead.org 
Having a stable wchan means the process must be blocked and for it to
stay that way while performing stack unwinding.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> [arm]
Tested-by: Mark Rutland <mark.rutland@arm.com> [arm64]
Link: https://lkml.kernel.org/r/20211008111626.332092234@infradead.org
powerpc/64: drop redundant defination of spin_until_cond 2021-06-16T14:09:11+00:00 Sudeep Holla sudeep.holla@arm.com 2021-06-11T19:10:57+00:00 db8f7066dc498acf9074ed3c11a7a24f318d8d4f linux/processor.h has exactly same defination for spin_until_cond. Drop the redundant defination in asm/processor.h Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1fff2054e5dfc00329804dbd3f2a91667c9a8aff.1623438544.git.christophe.leroy@csgroup.eu 
linux/processor.h has exactly same defination for spin_until_cond.
Drop the redundant defination in asm/processor.h

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1fff2054e5dfc00329804dbd3f2a91667c9a8aff.1623438544.git.christophe.leroy@csgroup.eu
powerpc/32s: Rework Kernel Userspace Access Protection 2021-06-16T14:09:08+00:00 Christophe Leroy christophe.leroy@csgroup.eu 2021-06-03T08:41:44+00:00 16132529cee586ee9a058bb33cfbdcb5d884f6b3 On book3s/32, KUAP is provided by toggling Ks bit in segment registers. One segment register addresses 256M of virtual memory. At the time being, KUAP implements a complex logic to apply the unlock/lock on the exact number of segments covering the user range to access, with saving the boundaries of the range of segments in a member of thread struct. But most if not all user accesses are within a single segment. Rework KUAP with a different approach: - Open only one segment, the one corresponding to the starting address of the range to be accessed. - If a second segment is involved, it will generate a page fault. The segment will then be open by the page fault handler. The kuap member of thread struct will now contain: - The start address of the current on going user access, that will be used to know which segment to lock at the end of the user access. - ~0 when no user access is open - ~1 when additionnal segments are opened by a page fault. Then, at lock time - When only one segment is open, close it. - When several segments are open, close all user segments. Almost 100% of the time, only one segment will be involved. In interrupts, inline the function that unlock/lock all segments, because not inlining them implies a lot of register save/restore. With the patch, writing value 128 in userspace in perf_copy_attr() is done with 16 instructions: 3890: 93 82 04 dc stw r28,1244(r2) 3894: 7d 20 e5 26 mfsrin r9,r28 3898: 55 29 00 80 rlwinm r9,r9,0,2,0 389c: 7d 20 e1 e4 mtsrin r9,r28 38a0: 4c 00 01 2c isync 38a4: 39 20 00 80 li r9,128 38a8: 91 3c 00 00 stw r9,0(r28) 38ac: 81 42 04 dc lwz r10,1244(r2) 38b0: 39 00 ff ff li r8,-1 38b4: 91 02 04 dc stw r8,1244(r2) 38b8: 2c 0a ff fe cmpwi r10,-2 38bc: 41 82 00 88 beq 3944 <perf_copy_attr+0x36c> 38c0: 7d 20 55 26 mfsrin r9,r10 38c4: 65 29 40 00 oris r9,r9,16384 38c8: 7d 20 51 e4 mtsrin r9,r10 38cc: 4c 00 01 2c isync ... 3944: 48 00 00 01 bl 3944 <perf_copy_attr+0x36c> 3944: R_PPC_REL24 kuap_lock_all_ool Before the patch it was 118 instructions. In reality only 42 are executed in most cases, but GCC is not able to see that a properly aligned user access cannot involve more than one segment. 5060: 39 1d 00 04 addi r8,r29,4 5064: 3d 20 b0 00 lis r9,-20480 5068: 7c 08 48 40 cmplw r8,r9 506c: 40 81 00 08 ble 5074 <perf_copy_attr+0x2cc> 5070: 3d 00 b0 00 lis r8,-20480 5074: 39 28 ff ff addi r9,r8,-1 5078: 57 aa 00 06 rlwinm r10,r29,0,0,3 507c: 55 29 27 3e rlwinm r9,r9,4,28,31 5080: 39 29 00 01 addi r9,r9,1 5084: 7d 29 53 78 or r9,r9,r10 5088: 91 22 04 dc stw r9,1244(r2) 508c: 7d 20 ed 26 mfsrin r9,r29 5090: 55 29 00 80 rlwinm r9,r9,0,2,0 5094: 7c 08 50 40 cmplw r8,r10 5098: 40 81 00 c0 ble 5158 <perf_copy_attr+0x3b0> 509c: 7d 46 50 f8 not r6,r10 50a0: 7c c6 42 14 add r6,r6,r8 50a4: 54 c6 27 be rlwinm r6,r6,4,30,31 50a8: 7d 20 51 e4 mtsrin r9,r10 50ac: 3c ea 10 00 addis r7,r10,4096 50b0: 39 29 01 11 addi r9,r9,273 50b4: 7f 88 38 40 cmplw cr7,r8,r7 50b8: 55 29 02 06 rlwinm r9,r9,0,8,3 50bc: 40 9d 00 9c ble cr7,5158 <perf_copy_attr+0x3b0> 50c0: 2f 86 00 00 cmpwi cr7,r6,0 50c4: 41 9e 00 4c beq cr7,5110 <perf_copy_attr+0x368> 50c8: 2f 86 00 01 cmpwi cr7,r6,1 50cc: 41 9e 00 2c beq cr7,50f8 <perf_copy_attr+0x350> 50d0: 2f 86 00 02 cmpwi cr7,r6,2 50d4: 41 9e 00 14 beq cr7,50e8 <perf_copy_attr+0x340> 50d8: 7d 20 39 e4 mtsrin r9,r7 50dc: 39 29 01 11 addi r9,r9,273 50e0: 3c e7 10 00 addis r7,r7,4096 50e4: 55 29 02 06 rlwinm r9,r9,0,8,3 50e8: 7d 20 39 e4 mtsrin r9,r7 50ec: 39 29 01 11 addi r9,r9,273 50f0: 3c e7 10 00 addis r7,r7,4096 50f4: 55 29 02 06 rlwinm r9,r9,0,8,3 50f8: 7d 20 39 e4 mtsrin r9,r7 50fc: 3c e7 10 00 addis r7,r7,4096 5100: 39 29 01 11 addi r9,r9,273 5104: 7f 88 38 40 cmplw cr7,r8,r7 5108: 55 29 02 06 rlwinm r9,r9,0,8,3 510c: 40 9d 00 4c ble cr7,5158 <perf_copy_attr+0x3b0> 5110: 7d 20 39 e4 mtsrin r9,r7 5114: 39 29 01 11 addi r9,r9,273 5118: 3c c7 10 00 addis r6,r7,4096 511c: 55 29 02 06 rlwinm r9,r9,0,8,3 5120: 7d 20 31 e4 mtsrin r9,r6 5124: 39 29 01 11 addi r9,r9,273 5128: 3c c6 10 00 addis r6,r6,4096 512c: 55 29 02 06 rlwinm r9,r9,0,8,3 5130: 7d 20 31 e4 mtsrin r9,r6 5134: 39 29 01 11 addi r9,r9,273 5138: 3c c7 30 00 addis r6,r7,12288 513c: 55 29 02 06 rlwinm r9,r9,0,8,3 5140: 7d 20 31 e4 mtsrin r9,r6 5144: 3c e7 40 00 addis r7,r7,16384 5148: 39 29 01 11 addi r9,r9,273 514c: 7f 88 38 40 cmplw cr7,r8,r7 5150: 55 29 02 06 rlwinm r9,r9,0,8,3 5154: 41 9d ff bc bgt cr7,5110 <perf_copy_attr+0x368> 5158: 4c 00 01 2c isync 515c: 39 20 00 80 li r9,128 5160: 91 3d 00 00 stw r9,0(r29) 5164: 38 e0 00 00 li r7,0 5168: 90 e2 04 dc stw r7,1244(r2) 516c: 7d 20 ed 26 mfsrin r9,r29 5170: 65 29 40 00 oris r9,r9,16384 5174: 40 81 00 c0 ble 5234 <perf_copy_attr+0x48c> 5178: 7d 47 50 f8 not r7,r10 517c: 7c e7 42 14 add r7,r7,r8 5180: 54 e7 27 be rlwinm r7,r7,4,30,31 5184: 7d 20 51 e4 mtsrin r9,r10 5188: 3d 4a 10 00 addis r10,r10,4096 518c: 39 29 01 11 addi r9,r9,273 5190: 7c 08 50 40 cmplw r8,r10 5194: 55 29 02 06 rlwinm r9,r9,0,8,3 5198: 40 81 00 9c ble 5234 <perf_copy_attr+0x48c> 519c: 2c 07 00 00 cmpwi r7,0 51a0: 41 82 00 4c beq 51ec <perf_copy_attr+0x444> 51a4: 2c 07 00 01 cmpwi r7,1 51a8: 41 82 00 2c beq 51d4 <perf_copy_attr+0x42c> 51ac: 2c 07 00 02 cmpwi r7,2 51b0: 41 82 00 14 beq 51c4 <perf_copy_attr+0x41c> 51b4: 7d 20 51 e4 mtsrin r9,r10 51b8: 39 29 01 11 addi r9,r9,273 51bc: 3d 4a 10 00 addis r10,r10,4096 51c0: 55 29 02 06 rlwinm r9,r9,0,8,3 51c4: 7d 20 51 e4 mtsrin r9,r10 51c8: 39 29 01 11 addi r9,r9,273 51cc: 3d 4a 10 00 addis r10,r10,4096 51d0: 55 29 02 06 rlwinm r9,r9,0,8,3 51d4: 7d 20 51 e4 mtsrin r9,r10 51d8: 3d 4a 10 00 addis r10,r10,4096 51dc: 39 29 01 11 addi r9,r9,273 51e0: 7c 08 50 40 cmplw r8,r10 51e4: 55 29 02 06 rlwinm r9,r9,0,8,3 51e8: 40 81 00 4c ble 5234 <perf_copy_attr+0x48c> 51ec: 7d 20 51 e4 mtsrin r9,r10 51f0: 39 29 01 11 addi r9,r9,273 51f4: 3c ea 10 00 addis r7,r10,4096 51f8: 55 29 02 06 rlwinm r9,r9,0,8,3 51fc: 7d 20 39 e4 mtsrin r9,r7 5200: 39 29 01 11 addi r9,r9,273 5204: 3c e7 10 00 addis r7,r7,4096 5208: 55 29 02 06 rlwinm r9,r9,0,8,3 520c: 7d 20 39 e4 mtsrin r9,r7 5210: 39 29 01 11 addi r9,r9,273 5214: 3c ea 30 00 addis r7,r10,12288 5218: 55 29 02 06 rlwinm r9,r9,0,8,3 521c: 7d 20 39 e4 mtsrin r9,r7 5220: 3d 4a 40 00 addis r10,r10,16384 5224: 39 29 01 11 addi r9,r9,273 5228: 7c 08 50 40 cmplw r8,r10 522c: 55 29 02 06 rlwinm r9,r9,0,8,3 5230: 41 81 ff bc bgt 51ec <perf_copy_attr+0x444> 5234: 4c 00 01 2c isync Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Export the ool handlers to fix build errors] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/d9121f96a7c4302946839a0771f5d1daeeb6968c.1622708530.git.christophe.leroy@csgroup.eu 
On book3s/32, KUAP is provided by toggling Ks bit in segment registers.
One segment register addresses 256M of virtual memory.

At the time being, KUAP implements a complex logic to apply the
unlock/lock on the exact number of segments covering the user range
to access, with saving the boundaries of the range of segments in
a member of thread struct.

But most if not all user accesses are within a single segment.

Rework KUAP with a different approach:
- Open only one segment, the one corresponding to the starting
address of the range to be accessed.
- If a second segment is involved, it will generate a page fault. The
segment will then be open by the page fault handler.

The kuap member of thread struct will now contain:
- The start address of the current on going user access, that will be
used to know which segment to lock at the end of the user access.
- ~0 when no user access is open
- ~1 when additionnal segments are opened by a page fault.

Then, at lock time
- When only one segment is open, close it.
- When several segments are open, close all user segments.

Almost 100% of the time, only one segment will be involved.

In interrupts, inline the function that unlock/lock all segments,
because not inlining them implies a lot of register save/restore.

With the patch, writing value 128 in userspace in perf_copy_attr() is
done with 16 instructions:

    3890:	93 82 04 dc 	stw     r28,1244(r2)
    3894:	7d 20 e5 26 	mfsrin  r9,r28
    3898:	55 29 00 80 	rlwinm  r9,r9,0,2,0
    389c:	7d 20 e1 e4 	mtsrin  r9,r28
    38a0:	4c 00 01 2c 	isync

    38a4:	39 20 00 80 	li      r9,128
    38a8:	91 3c 00 00 	stw     r9,0(r28)

    38ac:	81 42 04 dc 	lwz     r10,1244(r2)
    38b0:	39 00 ff ff 	li      r8,-1
    38b4:	91 02 04 dc 	stw     r8,1244(r2)
    38b8:	2c 0a ff fe 	cmpwi   r10,-2
    38bc:	41 82 00 88 	beq     3944 <perf_copy_attr+0x36c>
    38c0:	7d 20 55 26 	mfsrin  r9,r10
    38c4:	65 29 40 00 	oris    r9,r9,16384
    38c8:	7d 20 51 e4 	mtsrin  r9,r10
    38cc:	4c 00 01 2c 	isync
...
    3944:	48 00 00 01 	bl      3944 <perf_copy_attr+0x36c>
			3944: R_PPC_REL24	kuap_lock_all_ool

Before the patch it was 118 instructions. In reality only 42 are
executed in most cases, but GCC is not able to see that a properly
aligned user access cannot involve more than one segment.

    5060:	39 1d 00 04 	addi    r8,r29,4
    5064:	3d 20 b0 00 	lis     r9,-20480
    5068:	7c 08 48 40 	cmplw   r8,r9
    506c:	40 81 00 08 	ble     5074 <perf_copy_attr+0x2cc>
    5070:	3d 00 b0 00 	lis     r8,-20480
    5074:	39 28 ff ff 	addi    r9,r8,-1
    5078:	57 aa 00 06 	rlwinm  r10,r29,0,0,3
    507c:	55 29 27 3e 	rlwinm  r9,r9,4,28,31
    5080:	39 29 00 01 	addi    r9,r9,1
    5084:	7d 29 53 78 	or      r9,r9,r10
    5088:	91 22 04 dc 	stw     r9,1244(r2)
    508c:	7d 20 ed 26 	mfsrin  r9,r29
    5090:	55 29 00 80 	rlwinm  r9,r9,0,2,0
    5094:	7c 08 50 40 	cmplw   r8,r10
    5098:	40 81 00 c0 	ble     5158 <perf_copy_attr+0x3b0>
    509c:	7d 46 50 f8 	not     r6,r10
    50a0:	7c c6 42 14 	add     r6,r6,r8
    50a4:	54 c6 27 be 	rlwinm  r6,r6,4,30,31
    50a8:	7d 20 51 e4 	mtsrin  r9,r10
    50ac:	3c ea 10 00 	addis   r7,r10,4096
    50b0:	39 29 01 11 	addi    r9,r9,273
    50b4:	7f 88 38 40 	cmplw   cr7,r8,r7
    50b8:	55 29 02 06 	rlwinm  r9,r9,0,8,3
    50bc:	40 9d 00 9c 	ble     cr7,5158 <perf_copy_attr+0x3b0>

    50c0:	2f 86 00 00 	cmpwi   cr7,r6,0
    50c4:	41 9e 00 4c 	beq     cr7,5110 <perf_copy_attr+0x368>
    50c8:	2f 86 00 01 	cmpwi   cr7,r6,1
    50cc:	41 9e 00 2c 	beq     cr7,50f8 <perf_copy_attr+0x350>
    50d0:	2f 86 00 02 	cmpwi   cr7,r6,2
    50d4:	41 9e 00 14 	beq     cr7,50e8 <perf_copy_attr+0x340>
    50d8:	7d 20 39 e4 	mtsrin  r9,r7
    50dc:	39 29 01 11 	addi    r9,r9,273
    50e0:	3c e7 10 00 	addis   r7,r7,4096
    50e4:	55 29 02 06 	rlwinm  r9,r9,0,8,3
    50e8:	7d 20 39 e4 	mtsrin  r9,r7
    50ec:	39 29 01 11 	addi    r9,r9,273
    50f0:	3c e7 10 00 	addis   r7,r7,4096
    50f4:	55 29 02 06 	rlwinm  r9,r9,0,8,3
    50f8:	7d 20 39 e4 	mtsrin  r9,r7
    50fc:	3c e7 10 00 	addis   r7,r7,4096
    5100:	39 29 01 11 	addi    r9,r9,273
    5104:	7f 88 38 40 	cmplw   cr7,r8,r7
    5108:	55 29 02 06 	rlwinm  r9,r9,0,8,3
    510c:	40 9d 00 4c 	ble     cr7,5158 <perf_copy_attr+0x3b0>
    5110:	7d 20 39 e4 	mtsrin  r9,r7
    5114:	39 29 01 11 	addi    r9,r9,273
    5118:	3c c7 10 00 	addis   r6,r7,4096
    511c:	55 29 02 06 	rlwinm  r9,r9,0,8,3
    5120:	7d 20 31 e4 	mtsrin  r9,r6
    5124:	39 29 01 11 	addi    r9,r9,273
    5128:	3c c6 10 00 	addis   r6,r6,4096
    512c:	55 29 02 06 	rlwinm  r9,r9,0,8,3
    5130:	7d 20 31 e4 	mtsrin  r9,r6
    5134:	39 29 01 11 	addi    r9,r9,273
    5138:	3c c7 30 00 	addis   r6,r7,12288
    513c:	55 29 02 06 	rlwinm  r9,r9,0,8,3
    5140:	7d 20 31 e4 	mtsrin  r9,r6
    5144:	3c e7 40 00 	addis   r7,r7,16384
    5148:	39 29 01 11 	addi    r9,r9,273
    514c:	7f 88 38 40 	cmplw   cr7,r8,r7
    5150:	55 29 02 06 	rlwinm  r9,r9,0,8,3
    5154:	41 9d ff bc 	bgt     cr7,5110 <perf_copy_attr+0x368>

    5158:	4c 00 01 2c 	isync
    515c:	39 20 00 80 	li      r9,128
    5160:	91 3d 00 00 	stw     r9,0(r29)

    5164:	38 e0 00 00 	li      r7,0
    5168:	90 e2 04 dc 	stw     r7,1244(r2)
    516c:	7d 20 ed 26 	mfsrin  r9,r29
    5170:	65 29 40 00 	oris    r9,r9,16384
    5174:	40 81 00 c0 	ble     5234 <perf_copy_attr+0x48c>
    5178:	7d 47 50 f8 	not     r7,r10
    517c:	7c e7 42 14 	add     r7,r7,r8
    5180:	54 e7 27 be 	rlwinm  r7,r7,4,30,31
    5184:	7d 20 51 e4 	mtsrin  r9,r10
    5188:	3d 4a 10 00 	addis   r10,r10,4096
    518c:	39 29 01 11 	addi    r9,r9,273
    5190:	7c 08 50 40 	cmplw   r8,r10
    5194:	55 29 02 06 	rlwinm  r9,r9,0,8,3
    5198:	40 81 00 9c 	ble     5234 <perf_copy_attr+0x48c>

    519c:	2c 07 00 00 	cmpwi   r7,0
    51a0:	41 82 00 4c 	beq     51ec <perf_copy_attr+0x444>
    51a4:	2c 07 00 01 	cmpwi   r7,1
    51a8:	41 82 00 2c 	beq     51d4 <perf_copy_attr+0x42c>
    51ac:	2c 07 00 02 	cmpwi   r7,2
    51b0:	41 82 00 14 	beq     51c4 <perf_copy_attr+0x41c>
    51b4:	7d 20 51 e4 	mtsrin  r9,r10
    51b8:	39 29 01 11 	addi    r9,r9,273
    51bc:	3d 4a 10 00 	addis   r10,r10,4096
    51c0:	55 29 02 06 	rlwinm  r9,r9,0,8,3
    51c4:	7d 20 51 e4 	mtsrin  r9,r10
    51c8:	39 29 01 11 	addi    r9,r9,273
    51cc:	3d 4a 10 00 	addis   r10,r10,4096
    51d0:	55 29 02 06 	rlwinm  r9,r9,0,8,3
    51d4:	7d 20 51 e4 	mtsrin  r9,r10
    51d8:	3d 4a 10 00 	addis   r10,r10,4096
    51dc:	39 29 01 11 	addi    r9,r9,273
    51e0:	7c 08 50 40 	cmplw   r8,r10
    51e4:	55 29 02 06 	rlwinm  r9,r9,0,8,3
    51e8:	40 81 00 4c 	ble     5234 <perf_copy_attr+0x48c>
    51ec:	7d 20 51 e4 	mtsrin  r9,r10
    51f0:	39 29 01 11 	addi    r9,r9,273
    51f4:	3c ea 10 00 	addis   r7,r10,4096
    51f8:	55 29 02 06 	rlwinm  r9,r9,0,8,3
    51fc:	7d 20 39 e4 	mtsrin  r9,r7
    5200:	39 29 01 11 	addi    r9,r9,273
    5204:	3c e7 10 00 	addis   r7,r7,4096
    5208:	55 29 02 06 	rlwinm  r9,r9,0,8,3
    520c:	7d 20 39 e4 	mtsrin  r9,r7
    5210:	39 29 01 11 	addi    r9,r9,273
    5214:	3c ea 30 00 	addis   r7,r10,12288
    5218:	55 29 02 06 	rlwinm  r9,r9,0,8,3
    521c:	7d 20 39 e4 	mtsrin  r9,r7
    5220:	3d 4a 40 00 	addis   r10,r10,16384
    5224:	39 29 01 11 	addi    r9,r9,273
    5228:	7c 08 50 40 	cmplw   r8,r10
    522c:	55 29 02 06 	rlwinm  r9,r9,0,8,3
    5230:	41 81 ff bc 	bgt     51ec <perf_copy_attr+0x444>

    5234:	4c 00 01 2c 	isync

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Export the ool handlers to fix build errors]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d9121f96a7c4302946839a0771f5d1daeeb6968c.1622708530.git.christophe.leroy@csgroup.eu
powerpc/64s: power4 nap fixup in C 2021-04-08T11:17:45+00:00 Nicholas Piggin npiggin@gmail.com 2021-04-06T02:55:08+00:00 98db179a78dd8379e9d2cbfc3f00224168a9344c There is no need for this to be in asm, use the new intrrupt entry wrapper. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Tested-by: Andreas Schwab <schwab@linux-m68k.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210406025508.821718-1-npiggin@gmail.com 
There is no need for this to be in asm, use the new intrrupt entry wrapper.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Tested-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210406025508.821718-1-npiggin@gmail.com
powerpc/math: Fix missing __user qualifier for get_user() and other sparse warnings 2021-03-29T02:22:12+00:00 Christophe Leroy christophe.leroy@csgroup.eu 2021-03-15T12:00:09+00:00 e448e1e774dc0ca307c17e961daf7ede2e635c57 Sparse reports the following problems: arch/powerpc/math-emu/math.c:228:21: warning: Using plain integer as NULL pointer arch/powerpc/math-emu/math.c:228:31: warning: Using plain integer as NULL pointer arch/powerpc/math-emu/math.c:228:41: warning: Using plain integer as NULL pointer arch/powerpc/math-emu/math.c:228:51: warning: Using plain integer as NULL pointer arch/powerpc/math-emu/math.c:237:13: warning: incorrect type in initializer (different address spaces) arch/powerpc/math-emu/math.c:237:13: expected unsigned int [noderef] __user *_gu_addr arch/powerpc/math-emu/math.c:237:13: got unsigned int [usertype] * arch/powerpc/math-emu/math.c:226:1: warning: symbol 'do_mathemu' was not declared. Should it be static? Add missing __user qualifier when casting pointer used in get_user() Use NULL instead of 0 to initialise opX local variables. Add a prototype for do_mathemu() (Added in processor.h like sparc) Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/e4d1aae7604d89c98a52dfd8ce8443462e595670.1615809591.git.christophe.leroy@csgroup.eu 
Sparse reports the following problems:

arch/powerpc/math-emu/math.c:228:21: warning: Using plain integer as NULL pointer
arch/powerpc/math-emu/math.c:228:31: warning: Using plain integer as NULL pointer
arch/powerpc/math-emu/math.c:228:41: warning: Using plain integer as NULL pointer
arch/powerpc/math-emu/math.c:228:51: warning: Using plain integer as NULL pointer
arch/powerpc/math-emu/math.c:237:13: warning: incorrect type in initializer (different address spaces)
arch/powerpc/math-emu/math.c:237:13:    expected unsigned int [noderef] __user *_gu_addr
arch/powerpc/math-emu/math.c:237:13:    got unsigned int [usertype] *
arch/powerpc/math-emu/math.c:226:1: warning: symbol 'do_mathemu' was not declared. Should it be static?

Add missing __user qualifier when casting pointer used in get_user()

Use NULL instead of 0 to initialise opX local variables.

Add a prototype for do_mathemu() (Added in processor.h like sparc)

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e4d1aae7604d89c98a52dfd8ce8443462e595670.1615809591.git.christophe.leroy@csgroup.eu
powerpc/32: Always enable data translation in exception prolog 2021-03-29T02:22:05+00:00 Christophe Leroy christophe.leroy@csgroup.eu 2021-03-12T12:50:22+00:00 7aa8dd67f15731f659390018b5c9fd95f5975b3d If the code can use a stack in vm area, it can also use a stack in linear space. Simplify code by removing old non VMAP stack code on PPC32. That means the data translation is now re-enabled early in exception prolog in all cases, not only when using VMAP stacks. While we are touching EXCEPTION_PROLOG macros, remove the unused for_rtas parameter in EXCEPTION_PROLOG_1. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7cd6440c60a7e8f4f035b245c57720f51e225aae.1615552866.git.christophe.leroy@csgroup.eu 
If the code can use a stack in vm area, it can also use a
stack in linear space.

Simplify code by removing old non VMAP stack code on PPC32.

That means the data translation is now re-enabled early in
exception prolog in all cases, not only when using VMAP stacks.

While we are touching EXCEPTION_PROLOG macros, remove the
unused for_rtas parameter in EXCEPTION_PROLOG_1.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/7cd6440c60a7e8f4f035b245c57720f51e225aae.1615552866.git.christophe.leroy@csgroup.eu
powerpc/32: Remove ksp_limit 2021-03-29T02:22:05+00:00 Christophe Leroy christophe.leroy@csgroup.eu 2021-03-12T12:50:21+00:00 5747230645562921b5bc19f6409f7af08fe17c6d ksp_limit is there to help detect stack overflows. That is specific to ppc32 as it was removed from ppc64 in commit cbc9565ee826 ("powerpc: Remove ksp_limit on ppc64"). There are other means for detecting stack overflows. As ppc64 has proven to not need it, ppc32 should be able to do without it too. Lets remove it and simplify exception handling. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/d789c3385b22e07bedc997613c0d26074cb513e7.1615552866.git.christophe.leroy@csgroup.eu 
ksp_limit is there to help detect stack overflows.
That is specific to ppc32 as it was removed from ppc64 in
commit cbc9565ee826 ("powerpc: Remove ksp_limit on ppc64").

There are other means for detecting stack overflows.

As ppc64 has proven to not need it, ppc32 should be able to do
without it too.

Lets remove it and simplify exception handling.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d789c3385b22e07bedc997613c0d26074cb513e7.1615552866.git.christophe.leroy@csgroup.eu
powerpc/book3s64/pkeys: Don't update SPRN_AMR when in kernel mode. 2020-12-03T14:01:26+00:00 Aneesh Kumar K.V aneesh.kumar@linux.ibm.com 2020-11-27T04:44:16+00:00 48a8ab4eeb8271f2a0e2ca3cf80844a59acca153 Now that kernel correctly store/restore userspace AMR/IAMR values, avoid manipulating AMR and IAMR from the kernel on behalf of userspace. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: Sandipan Das <sandipan@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201127044424.40686-15-aneesh.kumar@linux.ibm.com 
Now that kernel correctly store/restore userspace AMR/IAMR values, avoid
manipulating AMR and IAMR from the kernel on behalf of userspace.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Sandipan Das <sandipan@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201127044424.40686-15-aneesh.kumar@linux.ibm.com
powerpc/signal: Remove get_clean_sp() 2020-12-03T14:01:12+00:00 Christophe Leroy christophe.leroy@csgroup.eu 2020-08-18T17:19:21+00:00 0ecbc6ad18e324012234183e21805423f5e0cc79 get_clean_sp() is only used once in kernel/signal.c . GCC is smart enough to see that x & 0xffffffff is a nop calculation on PPC32, no need of a special PPC32 trivial version. Include the logic from the PPC64 version of get_clean_sp() directly in get_sigframe(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/13ef6510ce30a4867e043157b93af5bb8c67fb3b.1597770847.git.christophe.leroy@csgroup.eu 
get_clean_sp() is only used once in kernel/signal.c .

GCC is smart enough to see that x & 0xffffffff is a nop
calculation on PPC32, no need of a special PPC32 trivial version.

Include the logic from the PPC64 version of get_clean_sp() directly
in get_sigframe().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/13ef6510ce30a4867e043157b93af5bb8c67fb3b.1597770847.git.christophe.leroy@csgroup.eu
powerpc/signal: Don't manage floating point regs when no FPU 2020-12-03T14:01:11+00:00 Christophe Leroy christophe.leroy@csgroup.eu 2020-08-18T17:19:17+00:00 b6254ced4da6cf28d49fbffe24ee4b3286dcb3f4 There is no point in copying floating point regs when there is no FPU and MATH_EMULATION is not selected. Create a new CONFIG_PPC_FPU_REGS bool that is selected by CONFIG_MATH_EMULATION and CONFIG_PPC_FPU, and use it to opt out everything related to fp_state in thread_struct. The asm const used only by fpu.S are opted out with CONFIG_PPC_FPU as fpu.S build is conditionnal to CONFIG_PPC_FPU. The following app spends approx 8.1 seconds system time on an 8xx without the patch, and 7.0 seconds with the patch (13.5% reduction). On an 832x, it spends approx 2.6 seconds system time without the patch and 2.1 seconds with the patch (19% reduction). void sigusr1(int sig) { } int main(int argc, char **argv) { int i = 100000; signal(SIGUSR1, sigusr1); for (;i--;) raise(SIGUSR1); exit(0); } Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7569070083e6cd5b279bb5023da601aba3c06f3c.1597770847.git.christophe.leroy@csgroup.eu 
There is no point in copying floating point regs when there
is no FPU and MATH_EMULATION is not selected.

Create a new CONFIG_PPC_FPU_REGS bool that is selected by
CONFIG_MATH_EMULATION and CONFIG_PPC_FPU, and use it to
opt out everything related to fp_state in thread_struct.

The asm const used only by fpu.S are opted out with CONFIG_PPC_FPU
as fpu.S build is conditionnal to CONFIG_PPC_FPU.

The following app spends approx 8.1 seconds system time on an 8xx
without the patch, and 7.0 seconds with the patch (13.5% reduction).

On an 832x, it spends approx 2.6 seconds system time without
the patch and 2.1 seconds with the patch (19% reduction).

	void sigusr1(int sig) { }

	int main(int argc, char **argv)
	{
		int i = 100000;

		signal(SIGUSR1, sigusr1);
		for (;i--;)
			raise(SIGUSR1);
		exit(0);
	}

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/7569070083e6cd5b279bb5023da601aba3c06f3c.1597770847.git.christophe.leroy@csgroup.eu