The patch titled fbcon: don't use vc_resize() on initialization has been added to the -mm tree. Its filename is fbcon-dont-use-vc_resize-on-initialization.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: fbcon: don't use vc_resize() on initialization From: Johannes Weiner <hannes@xxxxxxxxxxx> Catalin and kmemleak spotted a leak of a VC screen buffer in vc_allocate() due to the following chain of events: vc_allocate() visual_init(init=1) vc->vc_sw->con_init(init=1) fbcon_init() vc_resize() vc->screen_buf = kmalloc() vc->screen_buf = kmalloc() The common way for the VC drivers is to set the screen dimension parameters manually in the init case and only call vc_resize() for !init - which allocates a screen buffer according to the new dimensions. fbcon instead would do vc_resize() unconditionally and afterwards set the dimensions manually (again) for !init - i.e. completely upside down. The vc_resize() allocated buffer would then get lost by vc_allocate() allocating a fresh one. Use vc_resize() only for actual resizing to close the leak. Set the dimensions manually only in initialization mode to remove the redundant setting in resize mode. The kmemleak trace from Catalin: unreferenced object 0xde158000 (size 12288): comm "Xorg", pid 1439, jiffies 4294961016 hex dump (first 32 bytes): 20 00 20 00 20 00 20 00 20 00 20 00 20 00 20 00 . . . . . . . . 20 00 20 00 20 00 20 00 20 00 20 00 20 00 20 00 . . . . . . . . backtrace: [<c006f74b>] __save_stack_trace+0x17/0x1c [<c006f81d>] create_object+0xcd/0x188 [<c01f5457>] kmemleak_alloc+0x1b/0x3c [<c006e303>] __kmalloc+0xdb/0xe8 [<c012cc4b>] vc_do_resize+0x73/0x1e0 [<c012cdf1>] vc_resize+0x15/0x18 [<c011afc1>] fbcon_init+0x1f9/0x2b8 [<c0129e87>] visual_init+0x9f/0xdc [<c012aff3>] vc_allocate+0x7f/0xfc [<c012b087>] con_open+0x17/0x80 [<c0120e43>] tty_open+0x1f7/0x2e4 [<c0072fa1>] chrdev_open+0x101/0x118 [<c006ffad>] __dentry_open+0x105/0x1cc [<c00700fd>] nameidata_to_filp+0x2d/0x38 [<c00788cd>] do_filp_open+0x2c1/0x54c [<c006fdff>] do_sys_open+0x3b/0xb4 Reported-by: Catalin Marinas <catalin.marinas@xxxxxxx> Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx> Tested-by: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Pekka Enberg <penberg@xxxxxxxxxxxxxx> Cc: Krzysztof Helt <krzysztof.h1@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/video/console/fbcon.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff -puN drivers/video/console/fbcon.c~fbcon-dont-use-vc_resize-on-initialization drivers/video/console/fbcon.c --- a/drivers/video/console/fbcon.c~fbcon-dont-use-vc_resize-on-initialization +++ a/drivers/video/console/fbcon.c @@ -1082,7 +1082,6 @@ static void fbcon_init(struct vc_data *v new_rows = FBCON_SWAP(ops->rotate, info->var.yres, info->var.xres); new_cols /= vc->vc_font.width; new_rows /= vc->vc_font.height; - vc_resize(vc, new_cols, new_rows); /* * We must always set the mode. The mode of the previous console @@ -1111,10 +1110,11 @@ static void fbcon_init(struct vc_data *v * vc_{cols,rows}, but we must not set those if we are only * resizing the console. */ - if (!init) { + if (init) { vc->vc_cols = new_cols; vc->vc_rows = new_rows; - } + } else + vc_resize(vc, new_cols, new_rows); if (logo) fbcon_prepare_logo(vc, info, cols, rows, new_cols, new_rows); _ Patches currently in -mm which might be from hannes@xxxxxxxxxxx are origin.patch fbcon-dont-use-vc_resize-on-initialization.patch mm-make-swap-token-dummies-static-inlines.patch mm-make-swap-token-dummies-static-inlines-fix.patch mm-make-swap-token-dummies-static-inlines-fix-2.patch mm-count-only-reclaimable-lru-pages-v2.patch vmscan-move-clearpageactive-from-move_active_pages-to-shrink_active_list.patch vmscan-kill-unnecessary-page-flag-test.patch vmscan-kill-unnecessary-prefetch.patch vmscan-use-add_page_to_lru_list-helper-function.patch vmscan-move-pgdeactivate-modification-to-shrink_active_list.patch mm-perform-non-atomic-test-clear-of-pg_mlocked-on-free.patch mm-warn-once-when-a-page-is-freed-with-pg_mlocked-set.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html