Commit 7f06f21d authored by Michael Neuling's avatar Michael Neuling Committed by Benjamin Herrenschmidt
Browse files

powerpc/tm: Add checking to treclaim/trechkpt 



If we do a treclaim and we are not in TM suspend mode, it results in a TM bad
thing (ie. a 0x700 program check).  Similarly if we do a trechkpt and we have
an active transaction or TEXASR Failure Summary (FS) is not set, we also take a
TM bad thing.

This should never happen, but if it does (ie. a kernel bug), the cause is
almost impossible to debug as the GPR state is mostly userspace and hence we
don't get a call chain.

This adds some checks in these cases case a BUG_ON() (in asm) in case we ever
hit these cases.  It moves the register saving around to preserve r1 till later
also.

Signed-off-by: default avatarMichael Neuling <mikey@neuling.org>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent ce0ac1fc

arch/powerpc/include/asm/reg.h

+1 −0
Original line number Diff line number Diff line
@@ -215,6 +215,7 @@ 
#define SPRN_TEXASR	0x82	/* Transaction EXception & Summary */

#define   TEXASR_FS	__MASK(63-36)	/* Transaction Failure Summary */

#define SPRN_TEXASRU	0x83	/* ''	   ''	   ''	 Upper 32  */

#define   TEXASR_FS     __MASK(63-36) /* TEXASR Failure Summary */

#define SPRN_TFHAR	0x80	/* Transaction Failure Handler Addr */

#define SPRN_CTRLF	0x088

#define SPRN_CTRLT	0x098

arch/powerpc/kernel/tm.S

+35 −3
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 
#include <asm/ppc-opcode.h>

#include <asm/ptrace.h>

#include <asm/reg.h>

#include <asm/bug.h>



#ifdef CONFIG_VSX

/* See fpu.S, this is borrowed from there */
@@ -175,6 +176,13 @@ dont_backup_vec: 
	stfd    fr0,FPSTATE_FPSCR(r7)



dont_backup_fp:

	/* Do sanity check on MSR to make sure we are suspended */

	li	r7, (MSR_TS_S)@higher

	srdi	r6, r14, 32

	and	r6, r6, r7

1:	tdeqi   r6, 0

	EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,0



	/* The moment we treclaim, ALL of our GPRs will switch

	 * to user register state.  (FPRs, CCR etc. also!)

	 * Use an sprg and a tm_scratch in the PACA to shuffle.
@@ -383,12 +391,10 @@ restore_gprs: 
	/* ******************** CR,LR,CCR,MSR ********** */

	ld	r4, _CTR(r7)

	ld	r5, _LINK(r7)

	ld	r6, _CCR(r7)

	ld	r8, _XER(r7)



	mtctr	r4

	mtlr	r5

	mtcr	r6

	mtxer	r8



	/* ******************** TAR ******************** */
@@ -404,7 +410,8 @@ restore_gprs: 
	li	r4, 0

	mtmsrd	r4, 1



	REST_4GPRS(0, r7)			/* GPR0-3 */

	REST_GPR(0, r7)				/* GPR0 */

	REST_2GPRS(2, r7)			/* GPR2-3 */

	REST_GPR(4, r7)				/* GPR4 */

	REST_4GPRS(8, r7)			/* GPR8-11 */

	REST_2GPRS(12, r7)			/* GPR12-13 */
@@ -416,6 +423,31 @@ restore_gprs: 
	mtspr	SPRN_DSCR, r5

	mtspr	SPRN_PPR, r6



	/* Do final sanity check on TEXASR to make sure FS is set.  Do this

	 * here before we load up the userspace r1 so any bugs we hit will get

	 * a call chain */

	mfspr	r5, SPRN_TEXASR

	srdi	r5, r5, 16

	li	r6, (TEXASR_FS)@h

	and	r6, r6, r5

1:	tdeqi	r6, 0

	EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,0



	/* Do final sanity check on MSR to make sure we are not transactional

	 * or suspended

	 */

	mfmsr   r6

	li	r5, (MSR_TS_MASK)@higher

	srdi	r6, r6, 32

	and	r6, r6, r5

1:	tdnei   r6, 0

	EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,0



	/* Restore CR */

	ld	r6, _CCR(r7)

	mtcr    r6



	REST_GPR(1, r7)				/* GPR1 */

	REST_GPR(5, r7)				/* GPR5-7 */

	REST_GPR(6, r7)

	ld	r7, GPR7(r7)

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