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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Yangbo Lu <yangbo.lu@nxp.com>,
	"David S . Miller" <davem@davemloft.net>,
	Sasha Levin <sashal@kernel.org>,
	netdev@vger.kernel.org
Subject: [PATCH AUTOSEL 5.10 25/33] ptp_qoriq: fix overflow in ptp_qoriq_adjfine() u64 calcalation
Date: Mon, 29 Mar 2021 18:22:13 -0400	[thread overview]
Message-ID: <20210329222222.2382987-25-sashal@kernel.org> (raw)
In-Reply-To: <20210329222222.2382987-1-sashal@kernel.org>

From: Yangbo Lu <yangbo.lu@nxp.com>

[ Upstream commit f51d7bf1dbe5522c51c93fe8faa5f4abbdf339cd ]

Current calculation for diff of TMR_ADD register value may have
64-bit overflow in this code line, when long type scaled_ppm is
large.

adj *= scaled_ppm;

This patch is to resolve it by using mul_u64_u64_div_u64().

Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/ptp/ptp_qoriq.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/ptp/ptp_qoriq.c b/drivers/ptp/ptp_qoriq.c
index beb5f74944cd..08f4cf0ad9e3 100644
--- a/drivers/ptp/ptp_qoriq.c
+++ b/drivers/ptp/ptp_qoriq.c
@@ -189,15 +189,16 @@ int ptp_qoriq_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
 	tmr_add = ptp_qoriq->tmr_add;
 	adj = tmr_add;
 
-	/* calculate diff as adj*(scaled_ppm/65536)/1000000
-	 * and round() to the nearest integer
+	/*
+	 * Calculate diff and round() to the nearest integer
+	 *
+	 * diff = adj * (ppb / 1000000000)
+	 *      = adj * scaled_ppm / 65536000000
 	 */
-	adj *= scaled_ppm;
-	diff = div_u64(adj, 8000000);
-	diff = (diff >> 13) + ((diff >> 12) & 1);
+	diff = mul_u64_u64_div_u64(adj, scaled_ppm, 32768000000);
+	diff = DIV64_U64_ROUND_UP(diff, 2);
 
 	tmr_add = neg_adj ? tmr_add - diff : tmr_add + diff;
-
 	ptp_qoriq->write(&regs->ctrl_regs->tmr_add, tmr_add);
 
 	return 0;
-- 
2.30.1


  parent reply	other threads:[~2021-03-29 22:27 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-29 22:21 [PATCH AUTOSEL 5.10 01/33] ARM: dts: am33xx: add aliases for mmc interfaces Sasha Levin
2021-03-29 22:21 ` [PATCH AUTOSEL 5.10 02/33] bus: ti-sysc: Fix warning on unbind if reset is not deasserted Sasha Levin
2021-03-29 22:21 ` [PATCH AUTOSEL 5.10 03/33] platform/x86: intel-hid: Support Lenovo ThinkPad X1 Tablet Gen 2 Sasha Levin
2021-03-29 22:21 ` [PATCH AUTOSEL 5.10 04/33] bpf, x86: Use kvmalloc_array instead kmalloc_array in bpf_jit_comp Sasha Levin
2021-03-29 22:21 ` [PATCH AUTOSEL 5.10 05/33] net/mlx5e: Enforce minimum value check for ICOSQ size Sasha Levin
2021-03-29 22:21 ` [PATCH AUTOSEL 5.10 06/33] net: pxa168_eth: Fix a potential data race in pxa168_eth_remove Sasha Levin
2021-03-29 22:21 ` [PATCH AUTOSEL 5.10 07/33] kunit: tool: Fix a python tuple typing error Sasha Levin
2021-03-29 22:21 ` [PATCH AUTOSEL 5.10 08/33] mISDN: fix crash in fritzpci Sasha Levin
2021-03-29 22:21 ` [PATCH AUTOSEL 5.10 09/33] net: correct sk_acceptq_is_full() Sasha Levin
2021-04-05 18:59   ` Marcelo Ricardo Leitner
2021-04-07 14:15     ` Sasha Levin
2021-03-29 22:21 ` [PATCH AUTOSEL 5.10 10/33] mac80211: fix double free in ibss_leave Sasha Levin
2021-03-29 22:21 ` [PATCH AUTOSEL 5.10 11/33] mac80211: Check crypto_aead_encrypt for errors Sasha Levin
2021-03-29 22:22 ` [PATCH AUTOSEL 5.10 12/33] mac80211: choose first enabled channel for monitor Sasha Levin
2021-03-29 22:22 ` [PATCH AUTOSEL 5.10 13/33] drm/msm/dsi_pll_7nm: Fix variable usage for pll_lockdet_rate Sasha Levin
2021-03-29 22:22 ` [PATCH AUTOSEL 5.10 14/33] drm/msm/adreno: a5xx_power: Don't apply A540 lm_setup to other GPUs Sasha Levin
2021-03-29 22:22 ` [PATCH AUTOSEL 5.10 15/33] drm/msm: Ratelimit invalid-fence message Sasha Levin
2021-03-29 22:22 ` [PATCH AUTOSEL 5.10 16/33] netfilter: conntrack: Fix gre tunneling over ipv6 Sasha Levin
2021-03-29 22:22 ` [PATCH AUTOSEL 5.10 17/33] netfilter: nftables: skip hook overlap logic if flowtable is stale Sasha Levin
2021-03-29 22:22 ` [PATCH AUTOSEL 5.10 18/33] net: ipa: fix init header command validation Sasha Levin
2021-03-29 22:22 ` [PATCH AUTOSEL 5.10 19/33] platform/x86: thinkpad_acpi: Allow the FnLock LED to change state Sasha Levin
2021-03-29 22:22 ` [PATCH AUTOSEL 5.10 20/33] kselftest/arm64: sve: Do not use non-canonical FFR register value Sasha Levin
2021-03-29 22:22 ` [PATCH AUTOSEL 5.10 21/33] drm/msm/disp/dpu1: icc path needs to be set before dpu runtime resume Sasha Levin
2021-03-29 22:22 ` [PATCH AUTOSEL 5.10 22/33] x86/build: Turn off -fcf-protection for realmode targets Sasha Levin
2021-03-29 22:22 ` [PATCH AUTOSEL 5.10 23/33] block: clear GD_NEED_PART_SCAN later in bdev_disk_changed Sasha Levin
2021-03-29 22:22 ` [PATCH AUTOSEL 5.10 24/33] platform/x86: intel_pmc_core: Ignore GBE LTR on Tiger Lake platforms Sasha Levin
2021-03-29 22:22 ` Sasha Levin [this message]
2021-03-29 22:22 ` [PATCH AUTOSEL 5.10 26/33] scsi: target: pscsi: Clean up after failure in pscsi_map_sg() Sasha Levin
2021-03-29 22:22 ` [PATCH AUTOSEL 5.10 27/33] selftests/vm: fix out-of-tree build Sasha Levin
2021-03-29 22:22 ` [PATCH AUTOSEL 5.10 28/33] ia64: mca: allocate early mca with GFP_ATOMIC Sasha Levin
2021-03-29 22:22 ` [PATCH AUTOSEL 5.10 29/33] ia64: fix format strings for err_inject Sasha Levin
2021-03-29 22:22 ` [PATCH AUTOSEL 5.10 30/33] cifs: revalidate mapping when we open files for SMB1 POSIX Sasha Levin
2021-03-29 22:22 ` [PATCH AUTOSEL 5.10 31/33] cifs: Silently ignore unknown oplock break handle Sasha Levin
2021-03-29 22:22 ` [PATCH AUTOSEL 5.10 32/33] io_uring: fix timeout cancel return code Sasha Levin
2021-03-29 22:22 ` [PATCH AUTOSEL 5.10 33/33] math: Export mul_u64_u64_div_u64 Sasha Levin

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