Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932181AbbG1HsU (ORCPT ); Tue, 28 Jul 2015 03:48:20 -0400 Received: from eusmtp01.atmel.com ([212.144.249.242]:41727 "EHLO eusmtp01.atmel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932109AbbG1HsQ (ORCPT ); Tue, 28 Jul 2015 03:48:16 -0400 From: Ludovic Desroches To: CC: , , , Nicolas Ferre , Boris Brezillon , , Subject: [RESEND PATCH] pinctrl: at91: fix null pointer dereference Date: Tue, 28 Jul 2015 09:48:16 +0200 Message-ID: <1438069696-25303-1-git-send-email-ludovic.desroches@atmel.com> X-Mailer: git-send-email 2.2.0 In-Reply-To: <20150715133048.GD14886@odux.rfo.atmel.com> References: <20150715133048.GD14886@odux.rfo.atmel.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5712 Lines: 120 From: David Dueck Not all gpio banks are necessarily enabled, in the current code this can lead to null pointer dereferences. [ 51.130000] Unable to handle kernel NULL pointer dereference at virtual address 00000058 [ 51.130000] pgd = dee04000 [ 51.130000] [00000058] *pgd=3f66d831, *pte=00000000, *ppte=00000000 [ 51.140000] Internal error: Oops: 17 [#1] ARM [ 51.140000] Modules linked in: [ 51.140000] CPU: 0 PID: 1664 Comm: cat Not tainted 4.1.1+ #6 [ 51.140000] Hardware name: Atmel SAMA5 [ 51.140000] task: df6dd880 ti: dec60000 task.ti: dec60000 [ 51.140000] PC is at at91_pinconf_get+0xb4/0x200 [ 51.140000] LR is at at91_pinconf_get+0xb4/0x200 [ 51.140000] pc : [] lr : [] psr: 600f0013 sp : dec61e48 ip : 600f0013 fp : df522538 [ 51.140000] r10: df52250c r9 : 00000058 r8 : 00000068 [ 51.140000] r7 : 00000000 r6 : df53c910 r5 : 00000000 r4 : dec61e7c [ 51.140000] r3 : 00000000 r2 : c06746d4 r1 : 00000000 r0 : 00000003 [ 51.140000] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user [ 51.140000] Control: 10c53c7d Table: 3ee04059 DAC: 00000015 [ 51.140000] Process cat (pid: 1664, stack limit = 0xdec60208) [ 51.140000] Stack: (0xdec61e48 to 0xdec62000) [ 51.140000] 1e40: 00000358 00000000 df522500 ded15f80 c05a9d08 ded15f80 [ 51.140000] 1e60: 0000048c 00000061 df522500 ded15f80 c05a9d08 c01e7304 ded15f80 00000000 [ 51.140000] 1e80: c01e6008 00000060 0000048c c01e6034 c01e5f6c ded15f80 dec61ec0 00000000 [ 51.140000] 1ea0: 00020000 ded6f280 dec61f80 00000001 00000001 c00ae0b8 b6e80000 ded15fb0 [ 51.140000] 1ec0: 00000000 00000000 df4bc974 00000055 00000800 ded6f280 b6e80000 ded6f280 [ 51.140000] 1ee0: ded6f280 00020000 b6e80000 00000000 00020000 c0090dec c0671e1c dec61fb0 [ 51.140000] 1f00: b6f8b510 00000001 00004201 c000924c 00000000 00000003 00000003 00000000 [ 51.140000] 1f20: df4bc940 00022000 00000022 c066e188 b6e7f000 c00836f4 000b6e7f ded6f280 [ 51.140000] 1f40: ded6f280 b6e80000 dec61f80 ded6f280 00020000 c0091508 00000000 00000003 [ 51.140000] 1f60: 00022000 00000000 00000000 ded6f280 ded6f280 00020000 b6e80000 c0091d9c [ 51.140000] 1f80: 00000000 00000000 ffffffff 00020000 00020000 b6e80000 00000003 c000f124 [ 51.140000] 1fa0: dec60000 c000efa0 00020000 00020000 00000003 b6e80000 00020000 000271c4 [ 51.140000] 1fc0: 00020000 00020000 b6e80000 00000003 7fffe000 00000000 00000000 00020000 [ 51.140000] 1fe0: 00000000 bef50b64 00013835 b6f29c76 400f0030 00000003 00000000 00000000 [ 51.140000] [] (at91_pinconf_get) from [] (at91_pinconf_dbg_show+0x18/0x2c0) [ 51.140000] [] (at91_pinconf_dbg_show) from [] (pinconf_pins_show+0xc8/0xf8) [ 51.140000] [] (pinconf_pins_show) from [] (seq_read+0x1a0/0x464) [ 51.140000] [] (seq_read) from [] (__vfs_read+0x20/0xd0) [ 51.140000] [] (__vfs_read) from [] (vfs_read+0x7c/0x108) [ 51.140000] [] (vfs_read) from [] (SyS_read+0x40/0x94) [ 51.140000] [] (SyS_read) from [] (ret_fast_syscall+0x0/0x3c) [ 51.140000] Code: eb010ec2 e30a0d08 e34c005a eb0ae5a7 (e5993000) [ 51.150000] ---[ end trace fb3c370da3ea4794 ]--- Signed-off-by: David Dueck Acked-by: Ludovic Desroches Acked-by: Alexandre Belloni CC: Nicolas Ferre CC: Boris Brezillon CC: linux-arm-kernel@lists.infradead.org CC: linux-kernel@vger.kernel.org --- This patch fixes a oops in the kernel because of a NULL pointer in a table. Having a NULL pointer in this table is the normal behavior if a PIO controller is not enabled. So this fix is not a quick and dirty hack, it's usual to skip an entry from a table if it is not filled. drivers/pinctrl/pinctrl-at91.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/drivers/pinctrl/pinctrl-at91.c b/drivers/pinctrl/pinctrl-at91.c index a082447..2deb130 100644 --- a/drivers/pinctrl/pinctrl-at91.c +++ b/drivers/pinctrl/pinctrl-at91.c @@ -320,6 +320,9 @@ static const struct pinctrl_ops at91_pctrl_ops = { static void __iomem *pin_to_controller(struct at91_pinctrl *info, unsigned int bank) { + if (!gpio_chips[bank]) + return NULL; + return gpio_chips[bank]->regbase; } @@ -729,6 +732,10 @@ static int at91_pmx_set(struct pinctrl_dev *pctldev, unsigned selector, pin = &pins_conf[i]; at91_pin_dbg(info->dev, pin); pio = pin_to_controller(info, pin->bank); + + if (!pio) + continue; + mask = pin_to_mask(pin->pin); at91_mux_disable_interrupt(pio, mask); switch (pin->mux) { @@ -848,6 +855,10 @@ static int at91_pinconf_get(struct pinctrl_dev *pctldev, *config = 0; dev_dbg(info->dev, "%s:%d, pin_id=%d", __func__, __LINE__, pin_id); pio = pin_to_controller(info, pin_to_bank(pin_id)); + + if (!pio) + return -EINVAL; + pin = pin_id % MAX_NB_GPIO_PER_BANK; if (at91_mux_get_multidrive(pio, pin)) @@ -889,6 +900,10 @@ static int at91_pinconf_set(struct pinctrl_dev *pctldev, "%s:%d, pin_id=%d, config=0x%lx", __func__, __LINE__, pin_id, config); pio = pin_to_controller(info, pin_to_bank(pin_id)); + + if (!pio) + return -EINVAL; + pin = pin_id % MAX_NB_GPIO_PER_BANK; mask = pin_to_mask(pin); -- 2.2.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/