![Yamin Friedman](/assets/img/avatar_default.png)
While using net_dim, a dim_sample was used without ever initializing the
comps value. Added use of DIV_ROUND_DOWN_ULL() to prevent potential
overflow, it should not be a problem to save the final result in an int
because after the division by epms the value should not be larger than a
few thousand.
[ 1040.127124] UBSAN: Undefined behaviour in lib/dim/dim.c:78:23
[ 1040.130118] signed integer overflow:
[ 1040.131643] 134718714 * 100 cannot be represented in type 'int'
Fixes: 398c2b05bb
("linux/dim: Add completions count to dim_sample")
Signed-off-by: Yamin Friedman <yaminf@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Acked-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
84 lines
2.1 KiB
C
84 lines
2.1 KiB
C
// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
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/*
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* Copyright (c) 2019, Mellanox Technologies inc. All rights reserved.
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*/
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#include <linux/dim.h>
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bool dim_on_top(struct dim *dim)
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{
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switch (dim->tune_state) {
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case DIM_PARKING_ON_TOP:
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case DIM_PARKING_TIRED:
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return true;
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case DIM_GOING_RIGHT:
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return (dim->steps_left > 1) && (dim->steps_right == 1);
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default: /* DIM_GOING_LEFT */
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return (dim->steps_right > 1) && (dim->steps_left == 1);
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}
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}
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EXPORT_SYMBOL(dim_on_top);
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void dim_turn(struct dim *dim)
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{
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switch (dim->tune_state) {
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case DIM_PARKING_ON_TOP:
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case DIM_PARKING_TIRED:
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break;
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case DIM_GOING_RIGHT:
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dim->tune_state = DIM_GOING_LEFT;
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dim->steps_left = 0;
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break;
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case DIM_GOING_LEFT:
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dim->tune_state = DIM_GOING_RIGHT;
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dim->steps_right = 0;
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break;
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}
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}
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EXPORT_SYMBOL(dim_turn);
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void dim_park_on_top(struct dim *dim)
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{
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dim->steps_right = 0;
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dim->steps_left = 0;
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dim->tired = 0;
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dim->tune_state = DIM_PARKING_ON_TOP;
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}
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EXPORT_SYMBOL(dim_park_on_top);
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void dim_park_tired(struct dim *dim)
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{
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dim->steps_right = 0;
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dim->steps_left = 0;
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dim->tune_state = DIM_PARKING_TIRED;
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}
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EXPORT_SYMBOL(dim_park_tired);
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void dim_calc_stats(struct dim_sample *start, struct dim_sample *end,
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struct dim_stats *curr_stats)
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{
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/* u32 holds up to 71 minutes, should be enough */
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u32 delta_us = ktime_us_delta(end->time, start->time);
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u32 npkts = BIT_GAP(BITS_PER_TYPE(u32), end->pkt_ctr, start->pkt_ctr);
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u32 nbytes = BIT_GAP(BITS_PER_TYPE(u32), end->byte_ctr,
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start->byte_ctr);
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u32 ncomps = BIT_GAP(BITS_PER_TYPE(u32), end->comp_ctr,
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start->comp_ctr);
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if (!delta_us)
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return;
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curr_stats->ppms = DIV_ROUND_UP(npkts * USEC_PER_MSEC, delta_us);
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curr_stats->bpms = DIV_ROUND_UP(nbytes * USEC_PER_MSEC, delta_us);
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curr_stats->epms = DIV_ROUND_UP(DIM_NEVENTS * USEC_PER_MSEC,
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delta_us);
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curr_stats->cpms = DIV_ROUND_UP(ncomps * USEC_PER_MSEC, delta_us);
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if (curr_stats->epms != 0)
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curr_stats->cpe_ratio = DIV_ROUND_DOWN_ULL(
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curr_stats->cpms * 100, curr_stats->epms);
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else
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curr_stats->cpe_ratio = 0;
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}
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EXPORT_SYMBOL(dim_calc_stats);
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