From 4a5691c0f7b65b7aa9d237e55f05e691352caac7 Mon Sep 17 00:00:00 2001 From: Anton Vorontsov Date: Fri, 28 Mar 2008 14:16:09 -0700 Subject: [PATCH] mtd: maps/physmap: fix oops in suspend/resume/shutdown ops # reboot ... [ 42.351266] Flash device refused suspend due to active operation (state 0) [ 42.358195] Unable to handle kernel NULL pointer dereference at virtual address 00000078 [ 42.360060] pgd = c7d9c000 [ 42.362769] [00000078] *pgd=a7d8d031, *pte=00000000, *ppte=00000000 [ 42.372902] Internal error: Oops: 17 [#1] [ 42.376911] Modules linked in: [ 42.379980] CPU: 0 Not tainted (2.6.25-rc2-10642-ge8f2594-dirty #73) [ 42.380000] PC is at physmap_flash_shutdown+0x28/0x54 ... [ 42.380000] Backtrace: [ 42.380000] [] (physmap_flash_shutdown+0x0/0x54) from [] (platform_drv_shutdown+0x20/0x24) [ 42.380000] r5:28121969 r4:c0229e08 [ 42.380000] [] (platform_drv_shutdown+0x0/0x24) from [] (device_shutdown+0x60/0x88) [ 42.380000] [] (device_shutdown+0x0/0x88) from [] (kernel_restart_prepare+0x2c/0x3c) [ 42.380000] r4:00000000 [ 42.380000] [] (kernel_restart_prepare+0x0/0x3c) from [] (kernel_restart+0x14/0x48) [ 42.380000] [] (kernel_restart+0x0/0x48) from [] (sys_reboot+0xe8/0x1f8) [ 42.380000] r4:01234567 [ 42.380000] [] (sys_reboot+0x0/0x1f8) from [] (ret_fast_syscall+0x0/0x2c) [ 42.380000] r7:00000058 r6:00000004 r5:00000001 r4:00000000 [ 42.380000] Code: 0a000009 e7953004 e1a00003 e1a0e00f (e593f078) [ 42.650051] ---[ end trace 6d6c26a0fc3141de ]--- Segmentation fault INIT: no more processes left in this runlevel While looping for mtd[i]s, we should stop at the mtd[i] == NULL. This patch also removes unnecessary "if (info)" checks: suspend/resume/shutdown ops are executed only if probe() is succeeded, so info is guaranteed to be !NULL. Signed-off-by: Anton Vorontsov Cc: David Brownell Cc: David Woodhouse Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/mtd/maps/physmap.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/drivers/mtd/maps/physmap.c b/drivers/mtd/maps/physmap.c index f00e04efbe..bc4649a17b 100644 --- a/drivers/mtd/maps/physmap.c +++ b/drivers/mtd/maps/physmap.c @@ -202,9 +202,8 @@ static int physmap_flash_suspend(struct platform_device *dev, pm_message_t state int ret = 0; int i; - if (info) - for (i = 0; i < MAX_RESOURCES; i++) - ret |= info->mtd[i]->suspend(info->mtd[i]); + for (i = 0; i < MAX_RESOURCES && info->mtd[i]; i++) + ret |= info->mtd[i]->suspend(info->mtd[i]); return ret; } @@ -214,9 +213,9 @@ static int physmap_flash_resume(struct platform_device *dev) struct physmap_flash_info *info = platform_get_drvdata(dev); int i; - if (info) - for (i = 0; i < MAX_RESOURCES; i++) - info->mtd[i]->resume(info->mtd[i]); + for (i = 0; i < MAX_RESOURCES && info->mtd[i]; i++) + info->mtd[i]->resume(info->mtd[i]); + return 0; } @@ -225,8 +224,8 @@ static void physmap_flash_shutdown(struct platform_device *dev) struct physmap_flash_info *info = platform_get_drvdata(dev); int i; - for (i = 0; i < MAX_RESOURCES; i++) - if (info && info->mtd[i]->suspend(info->mtd[i]) == 0) + for (i = 0; i < MAX_RESOURCES && info->mtd[i]; i++) + if (info->mtd[i]->suspend(info->mtd[i]) == 0) info->mtd[i]->resume(info->mtd[i]); } #else -- 2.39.5