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Commit 02a5fec1 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'powerpc-4.4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux 

Pull powerpc fixes from Michael Ellerman:

 - tm: Block signal return from setting invalid MSR state from Michael
   Neuling

 - tm: Check for already reclaimed tasks from Michael Neuling

* tag 'powerpc-4.4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/tm: Check for already reclaimed tasks
  powerpc/tm: Block signal return setting invalid MSR state
parents 78c4a49a 7f821fc9

arch/powerpc/include/asm/reg.h

+1 −0
Original line number Diff line number Diff line
@@ -108,6 +108,7 @@ 
#define MSR_TS_T	__MASK(MSR_TS_T_LG)	/*  Transaction Transactional */

#define MSR_TS_MASK	(MSR_TS_T | MSR_TS_S)   /* Transaction State bits */

#define MSR_TM_ACTIVE(x) (((x) & MSR_TS_MASK) != 0) /* Transaction active? */

#define MSR_TM_RESV(x) (((x) & MSR_TS_MASK) == MSR_TS_MASK) /* Reserved */

#define MSR_TM_TRANSACTIONAL(x)	(((x) & MSR_TS_MASK) == MSR_TS_T)

#define MSR_TM_SUSPENDED(x)	(((x) & MSR_TS_MASK) == MSR_TS_S)

arch/powerpc/kernel/process.c

+18 −0
Original line number Diff line number Diff line
@@ -551,6 +551,24 @@ static void tm_reclaim_thread(struct thread_struct *thr, 
		msr_diff &= MSR_FP | MSR_VEC | MSR_VSX | MSR_FE0 | MSR_FE1;

	}



	/*

	 * Use the current MSR TM suspended bit to track if we have

	 * checkpointed state outstanding.

	 * On signal delivery, we'd normally reclaim the checkpointed

	 * state to obtain stack pointer (see:get_tm_stackpointer()).

	 * This will then directly return to userspace without going

	 * through __switch_to(). However, if the stack frame is bad,

	 * we need to exit this thread which calls __switch_to() which

	 * will again attempt to reclaim the already saved tm state.

	 * Hence we need to check that we've not already reclaimed

	 * this state.

	 * We do this using the current MSR, rather tracking it in

	 * some specific thread_struct bit, as it has the additional

	 * benifit of checking for a potential TM bad thing exception.

	 */

	if (!MSR_TM_SUSPENDED(mfmsr()))

		return;



	tm_reclaim(thr, thr->regs->msr, cause);



	/* Having done the reclaim, we now have the checkpointed

arch/powerpc/kernel/signal_32.c

+9 −5
Original line number Diff line number Diff line
@@ -875,6 +875,15 @@ static long restore_tm_user_regs(struct pt_regs *regs, 
		return 1;

#endif /* CONFIG_SPE */



	/* Get the top half of the MSR from the user context */

	if (__get_user(msr_hi, &tm_sr->mc_gregs[PT_MSR]))

		return 1;

	msr_hi <<= 32;

	/* If TM bits are set to the reserved value, it's an invalid context */

	if (MSR_TM_RESV(msr_hi))

		return 1;

	/* Pull in the MSR TM bits from the user context */

	regs->msr = (regs->msr & ~MSR_TS_MASK) | (msr_hi & MSR_TS_MASK);

	/* Now, recheckpoint.  This loads up all of the checkpointed (older)

	 * registers, including FP and V[S]Rs.  After recheckpointing, the

	 * transactional versions should be loaded.
@@ -884,11 +893,6 @@ static long restore_tm_user_regs(struct pt_regs *regs, 
	current->thread.tm_texasr |= TEXASR_FS;

	/* This loads the checkpointed FP/VEC state, if used */

	tm_recheckpoint(&current->thread, msr);

	/* Get the top half of the MSR */

	if (__get_user(msr_hi, &tm_sr->mc_gregs[PT_MSR]))

		return 1;

	/* Pull in MSR TM from user context */

	regs->msr = (regs->msr & ~MSR_TS_MASK) | ((msr_hi<<32) & MSR_TS_MASK);



	/* This loads the speculative FP/VEC state, if used */

	if (msr & MSR_FP) {

arch/powerpc/kernel/signal_64.c

+4 −0
Original line number Diff line number Diff line
@@ -438,6 +438,10 @@ static long restore_tm_sigcontexts(struct pt_regs *regs, 


	/* get MSR separately, transfer the LE bit if doing signal return */

	err |= __get_user(msr, &sc->gp_regs[PT_MSR]);

	/* Don't allow reserved mode. */

	if (MSR_TM_RESV(msr))

		return -EINVAL;



	/* pull in MSR TM from user context */

	regs->msr = (regs->msr & ~MSR_TS_MASK) | (msr & MSR_TS_MASK);