/* * Support for the w100 frame buffer. * * Copyright (c) 2004-2005 Richard Purdie * Copyright (c) 2005 Ian Molton * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #define W100_GPIO_PORT_A 0 #define W100_GPIO_PORT_B 1 #define CLK_SRC_XTAL 0 #define CLK_SRC_PLL 1 struct w100fb_par; unsigned long w100fb_gpio_read(int port); void w100fb_gpio_write(int port, unsigned long value); unsigned long w100fb_get_hsynclen(struct device *dev); /* LCD Specific Routines and Config */ struct w100_tg_info { void (*change)(struct w100fb_par*); void (*suspend)(struct w100fb_par*); void (*resume)(struct w100fb_par*); }; /* General Platform Specific w100 Register Values */ struct w100_gen_regs { unsigned long lcd_format; unsigned long lcdd_cntl1; unsigned long lcdd_cntl2; unsigned long genlcd_cntl1; unsigned long genlcd_cntl2; unsigned long genlcd_cntl3; }; struct w100_gpio_regs { unsigned long init_data1; unsigned long init_data2; unsigned long gpio_dir1; unsigned long gpio_oe1; unsigned long gpio_dir2; unsigned long gpio_oe2; }; /* Optional External Memory Configuration */ struct w100_mem_info { unsigned long ext_cntl; unsigned long sdram_mode_reg; unsigned long ext_timing_cntl; unsigned long io_cntl; unsigned int size; }; struct w100_bm_mem_info { unsigned long ext_mem_bw; unsigned long offset; unsigned long ext_timing_ctl; unsigned long ext_cntl; unsigned long mode_reg; unsigned long io_cntl; unsigned long config; }; /* LCD Mode definition */ struct w100_mode { unsigned int xres; unsigned int yres; unsigned short left_margin; unsigned short right_margin; unsigned short upper_margin; unsigned short lower_margin; unsigned long crtc_ss; unsigned long crtc_ls; unsigned long crtc_gs; unsigned long crtc_vpos_gs; unsigned long crtc_rev; unsigned long crtc_dclk; unsigned long crtc_gclk; unsigned long crtc_goe; unsigned long crtc_ps1_active; char pll_freq; char fast_pll_freq; int sysclk_src; int sysclk_divider; int pixclk_src; int pixclk_divider; int pixclk_divider_rotated; }; struct w100_pll_info { uint16_t freq; /* desired Fout for PLL (Mhz) */ uint8_t M; /* input divider */ uint8_t N_int; /* VCO multiplier */ uint8_t N_fac; /* VCO multiplier fractional part */ uint8_t tfgoal; uint8_t lock_time; }; /* Initial Video mode orientation flags */ #define INIT_MODE_ROTATED 0x1 #define INIT_MODE_FLIPPED 0x2 /* * This structure describes the machine which we are running on. * It is set by machine specific code and used in the probe routine * of drivers/video/w100fb.c */ struct w100fb_mach_info { /* General Platform Specific Registers */ struct w100_gen_regs *regs; /* Table of modes the LCD is capable of */ struct w100_mode *modelist; unsigned int num_modes; /* Hooks for any platform specific tg/lcd code (optional) */ struct w100_tg_info *tg; /* External memory definition (if present) */ struct w100_mem_info *mem; /* Additional External memory definition (if present) */ struct w100_bm_mem_info *bm_mem; /* GPIO definitions (optional) */ struct w100_gpio_regs *gpio; /* Initial Mode flags */ unsigned int init_mode; /* Xtal Frequency */ unsigned int xtal_freq; /* Enable Xtal input doubler (1 == enable) */ unsigned int xtal_dbl; }; /* General frame buffer data structure */ struct w100fb_par { unsigned int chip_id; unsigned int xres; unsigned int yres; unsigned int extmem_active; unsigned int flip; unsigned int blanked; unsigned int fastpll_mode; unsigned long hsync_len; struct w100_mode *mode; struct w100_pll_info *pll_table; struct w100fb_mach_info *mach; uint32_t *saved_intmem; uint32_t *saved_extmem; }; 7'>7space:mode:
authorLuis R. Rodriguez <mcgrof@kernel.org>2017-01-25 10:31:52 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-01-27 09:19:48 +0100
commit191e885a2e130e639bb0c8ee350d7047294f2ce6 (patch)
tree9bf9f9b4971df55a46e0a6750d3f6cd37bf1d9f0 /sound/core/seq/seq_system.c
parent49def1853334396f948dcb4cedb9347abb318df5 (diff)
firmware: fix NULL pointer dereference in __fw_load_abort()
Since commit 5d47ec02c37ea6 ("firmware: Correct handling of fw_state_wait() return value") fw_load_abort() could be called twice and lead us to a kernel crash. This happens only when the firmware fallback mechanism (regular or custom) is used. The fallback mechanism exposes a sysfs interface for userspace to upload a file and notify the kernel when the file is loaded and ready, or to cancel an upload by echo'ing -1 into on the loading file: echo -n "-1" > /sys/$DEVPATH/loading This will call fw_load_abort(). Some distributions actually have a udev rule in place to *always* immediately cancel all firmware fallback mechanism requests (Debian), they have: $ cat /lib/udev/rules.d/50-firmware.rules # stub for immediately telling the kernel that userspace firmware loading # failed; necessary to avoid long timeouts with CONFIG_FW_LOADER_USER_HELPER=y SUBSYSTEM=="firmware", ACTION=="add", ATTR{loading}="-1 Distributions with this udev rule would run into this crash only if the fallback mechanism is used. Since most distributions disable by default using the fallback mechanism (CONFIG_FW_LOADER_USER_HELPER_FALLBACK), this would typicaly mean only 2 drivers which *require* the fallback mechanism could typically incur a crash: drivers/firmware/dell_rbu.c and the drivers/leds/leds-lp55xx-common.c driver. Distributions enabling CONFIG_FW_LOADER_USER_HELPER_FALLBACK by default are obviously more exposed to this crash. The crash happens because after commit 5b029624948d ("firmware: do not use fw_lock for fw_state protection") and subsequent fix commit 5d47ec02c37ea6 ("firmware: Correct handling of fw_state_wait() return value") a race can happen between this cancelation and the firmware fw_state_wait_timeout() being woken up after a state change with which fw_load_abort() as that calls swake_up(). Upon error fw_state_wait_timeout() will also again call fw_load_abort() and trigger a null reference. At first glance we could just fix this with a !buf check on fw_load_abort() before accessing buf->fw_st, however there is a logical issue in having a state machine used for the fallback mechanism and preventing access from it once we abort as its inside the buf (buf->fw_st). The firmware_class.c code is setting the buf to NULL to annotate an abort has occurred. Replace this mechanism by simply using the state check instead. All the other code in place already uses similar checks for aborting as well so no further changes are needed. An oops can be reproduced with the new fw_fallback.sh fallback mechanism cancellation test. Either cancelling the fallback mechanism or the custom fallback mechanism triggers a crash. mcgrof@piggy ~/linux-next/tools/testing/selftests/firmware (git::20170111-fw-fixes)$ sudo ./fw_fallback.sh ./fw_fallback.sh: timeout works ./fw_fallback.sh: firmware comparison works ./fw_fallback.sh: fallback mechanism works [ this then sits here when it is trying the cancellation test ] Kernel log: test_firmware: loading 'nope-test-firmware.bin' misc test_firmware: Direct firmware load for nope-test-firmware.bin failed with error -2 misc test_firmware: Falling back to user helper BUG: unable to handle kernel NULL pointer dereference at 0000000000000038 IP: _request_firmware+0xa27/0xad0 PGD 0 Oops: 0000 [#1] SMP Modules linked in: test_firmware(E) ... etc ... CPU: 1 PID: 1396 Comm: fw_fallback.sh Tainted: G W E 4.10.0-rc3-next-20170111+ #30 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.1-0-g8891697-prebuilt.qemu-project.org 04/01/2014 task: ffff9740b27f4340 task.stack: ffffbb15c0bc8000 RIP: 0010:_request_firmware+0xa27/0xad0 RSP: 0018:ffffbb15c0bcbd10 EFLAGS: 00010246 RAX: 00000000fffffffe RBX: ffff9740afe5aa80 RCX: 0000000000000000 RDX: ffff9740b27f4340 RSI: 0000000000000283 RDI: 0000000000000000 RBP: ffffbb15c0bcbd90 R08: ffffbb15c0bcbcd8 R09: 0000000000000000 R10: 0000000894a0d4b1 R11: 000000000000008c R12: ffffffffc0312480 R13: 0000000000000005 R14: ffff9740b1c32400 R15: 00000000000003e8 FS: 00007f8604422700(0000) GS:ffff9740bfc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000038 CR3: 000000012164c000 CR4: 00000000000006e0 Call Trace: request_firmware+0x37/0x50 trigger_request_store+0x79/0xd0 [test_firmware] dev_attr_store+0x18/0x30 sysfs_kf_write+0x37/0x40 kernfs_fop_write+0x110/0x1a0 __vfs_write+0x37/0x160 ? _cond_resched+0x1a/0x50 vfs_write+0xb5/0x1a0 SyS_write+0x55/0xc0 ? trace_do_page_fault+0x37/0xd0 entry_SYSCALL_64_fastpath+0x1e/0xad RIP: 0033:0x7f8603f49620 RSP: 002b:00007fff6287b788 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000055c307b110a0 RCX: 00007f8603f49620 RDX: 0000000000000016 RSI: 000055c3084d8a90 RDI: 0000000000000001 RBP: 0000000000000016 R08: 000000000000c0ff R09: 000055c3084d6336 R10: 000055c307b108b0 R11: 0000000000000246 R12: 000055c307b13c80 R13: 000055c3084d6320 R14: 0000000000000000 R15: 00007fff6287b950 Code: 9f 64 84 e8 9c 61 fe ff b8 f4 ff ff ff e9 6b f9 ff ff 48 c7 c7 40 6b 8d 84 89 45 a8 e8 43 84 18 00 49 8b be 00 03 00 00 8b 45 a8 <83> 7f 38 02 74 08 e8 6e ec ff ff 8b 45 a8 49 c7 86 00 03 00 00 RIP: _request_firmware+0xa27/0xad0 RSP: ffffbb15c0bcbd10 CR2: 0000000000000038 ---[ end trace 6d94ac339c133e6f ]--- Fixes: 5d47ec02c37e ("firmware: Correct handling of fw_state_wait() return value") Reported-and-Tested-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reported-and-Tested-by: Patrick Bruenn <p.bruenn@beckhoff.com> Reported-by: Chris Wilson <chris@chris-wilson.co.uk> CC: <stable@vger.kernel.org> [3.10+] Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'sound/core/seq/seq_system.c')