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rcutorture: Expand RCUTORTURE_RDR_MASK_[12] to eight bits

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This commit prepares for testing of multiple SRCU reader flavors by
expanding RCUTORTURE_RDR_MASK_1 and RCUTORTURE_RDR_MASK_2 from a single
bit to eight bits, allowing them to accommodate the return values from
multiple calls to srcu_read_lock*().  This will in turn permit better
testing coverage for these SRCU reader flavors, including testing of
the diagnostics for inproper use of mixed reader flavors.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: <bpf@vger.kernel.org>
Reviewed-by: Neeraj Upadhyay <Neeraj.Upadhyay@amd.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
This commit is contained in:
Paul E. McKenney 2024-10-15 09:11:07 -07:00 committed by Frederic Weisbecker
parent bb94b12e45
commit 37a1decb43
1 changed files with 14 additions and 14 deletions
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28
kernel/rcu/rcutorture.c
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@ -57,9 +57,9 @@ MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com> and Josh Triplett <josh@
/* Bits for ->extendables field, extendables param, and related definitions. */
#define RCUTORTURE_RDR_SHIFT_1 8 /* Put SRCU index in upper bits. */
#define RCUTORTURE_RDR_MASK_1 (1 << RCUTORTURE_RDR_SHIFT_1)
#define RCUTORTURE_RDR_SHIFT_2 9 /* Put SRCU index in upper bits. */
#define RCUTORTURE_RDR_MASK_2 (1 << RCUTORTURE_RDR_SHIFT_2)
#define RCUTORTURE_RDR_MASK_1 (0xff << RCUTORTURE_RDR_SHIFT_1)
#define RCUTORTURE_RDR_SHIFT_2 16 /* Put SRCU index in upper bits. */
#define RCUTORTURE_RDR_MASK_2 (0xff << RCUTORTURE_RDR_SHIFT_2)
#define RCUTORTURE_RDR_BH 0x01 /* Extend readers by disabling bh. */
#define RCUTORTURE_RDR_IRQ 0x02 /* ... disabling interrupts. */
#define RCUTORTURE_RDR_PREEMPT 0x04 /* ... disabling preemption. */
@ -71,6 +71,9 @@ MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com> and Josh Triplett <josh@
#define RCUTORTURE_MAX_EXTEND \
(RCUTORTURE_RDR_BH | RCUTORTURE_RDR_IRQ | RCUTORTURE_RDR_PREEMPT | \
RCUTORTURE_RDR_RBH | RCUTORTURE_RDR_SCHED)
#define RCUTORTURE_RDR_ALLBITS \
(RCUTORTURE_MAX_EXTEND | RCUTORTURE_RDR_RCU_1 | RCUTORTURE_RDR_RCU_2 | \
RCUTORTURE_RDR_MASK_1 | RCUTORTURE_RDR_MASK_2)
#define RCUTORTURE_RDR_MAX_LOOPS 0x7 /* Maximum reader extensions. */
/* Must be power of two minus one. */
#define RCUTORTURE_RDR_MAX_SEGS (RCUTORTURE_RDR_MAX_LOOPS + 3)
@ -1820,7 +1823,7 @@ static void rcutorture_one_extend(int *readstate, int newstate,
int statesold = *readstate & ~newstate;
WARN_ON_ONCE(idxold2 < 0);
WARN_ON_ONCE((idxold2 >> RCUTORTURE_RDR_SHIFT_2) > 1);
WARN_ON_ONCE(idxold2 & ~RCUTORTURE_RDR_ALLBITS);
rtrsp->rt_readstate = newstate;
/* First, put new protection in place to avoid critical-section gap. */
@ -1835,9 +1838,9 @@ static void rcutorture_one_extend(int *readstate, int newstate,
if (statesnew & RCUTORTURE_RDR_SCHED)
rcu_read_lock_sched();
if (statesnew & RCUTORTURE_RDR_RCU_1)
idxnew1 = (cur_ops->readlock() & 0x1) << RCUTORTURE_RDR_SHIFT_1;
idxnew1 = (cur_ops->readlock() << RCUTORTURE_RDR_SHIFT_1) & RCUTORTURE_RDR_MASK_1;
if (statesnew & RCUTORTURE_RDR_RCU_2)
idxnew2 = (cur_ops->readlock() & 0x1) << RCUTORTURE_RDR_SHIFT_2;
idxnew2 = (cur_ops->readlock() << RCUTORTURE_RDR_SHIFT_2) & RCUTORTURE_RDR_MASK_2;
/*
* Next, remove old protection, in decreasing order of strength
@ -1857,7 +1860,7 @@ static void rcutorture_one_extend(int *readstate, int newstate,
if (statesold & RCUTORTURE_RDR_RBH)
rcu_read_unlock_bh();
if (statesold & RCUTORTURE_RDR_RCU_2) {
cur_ops->readunlock((idxold2 >> RCUTORTURE_RDR_SHIFT_2) & 0x1);
cur_ops->readunlock((idxold2 & RCUTORTURE_RDR_MASK_2) >> RCUTORTURE_RDR_SHIFT_2);
WARN_ON_ONCE(idxnew2 != -1);
idxold2 = 0;
}
@ -1867,7 +1870,7 @@ static void rcutorture_one_extend(int *readstate, int newstate,
lockit = !cur_ops->no_pi_lock && !statesnew && !(torture_random(trsp) & 0xffff);
if (lockit)
raw_spin_lock_irqsave(&current->pi_lock, flags);
cur_ops->readunlock((idxold1 >> RCUTORTURE_RDR_SHIFT_1) & 0x1);
cur_ops->readunlock((idxold1 & RCUTORTURE_RDR_MASK_1) >> RCUTORTURE_RDR_SHIFT_1);
WARN_ON_ONCE(idxnew1 != -1);
idxold1 = 0;
if (lockit)
@ -1882,16 +1885,13 @@ static void rcutorture_one_extend(int *readstate, int newstate,
if (idxnew1 == -1)
idxnew1 = idxold1 & RCUTORTURE_RDR_MASK_1;
WARN_ON_ONCE(idxnew1 < 0);
if (WARN_ON_ONCE((idxnew1 >> RCUTORTURE_RDR_SHIFT_1) > 1))
pr_info("Unexpected idxnew1 value of %#x\n", idxnew1);
if (idxnew2 == -1)
idxnew2 = idxold2 & RCUTORTURE_RDR_MASK_2;
WARN_ON_ONCE(idxnew2 < 0);
WARN_ON_ONCE((idxnew2 >> RCUTORTURE_RDR_SHIFT_2) > 1);
*readstate = idxnew1 | idxnew2 | newstate;
WARN_ON_ONCE(*readstate < 0);
if (WARN_ON_ONCE((*readstate >> RCUTORTURE_RDR_SHIFT_2) > 1))
pr_info("Unexpected idxnew2 value of %#x\n", idxnew2);
if (WARN_ON_ONCE(*readstate & ~RCUTORTURE_RDR_ALLBITS))
pr_info("Unexpected readstate value of %#x\n", *readstate);
}
/* Return the biggest extendables mask given current RCU and boot parameters. */
@ -1916,7 +1916,7 @@ rcutorture_extend_mask(int oldmask, struct torture_random_state *trsp)
unsigned long preempts_irq = preempts | RCUTORTURE_RDR_IRQ;
unsigned long bhs = RCUTORTURE_RDR_BH | RCUTORTURE_RDR_RBH;
WARN_ON_ONCE(mask >> RCUTORTURE_RDR_SHIFT_1);
WARN_ON_ONCE(mask >> RCUTORTURE_RDR_SHIFT_1); // Can't have reader idx bits.
/* Mostly only one bit (need preemption!), sometimes lots of bits. */
if (!(randmask1 & 0x7))
mask = mask & randmask2;