From 5e322beefc8699b5747cfb35539a9496034e4296 Mon Sep 17 00:00:00 2001 From: Vlastimil Babka Date: Thu, 10 Nov 2016 10:46:07 -0800 Subject: mm, frontswap: make sure allocated frontswap map is assigned Christian Borntraeger reports: With commit 8ea1d2a1985a ("mm, frontswap: convert frontswap_enabled to static key") kmemleak complains about a memory leak in swapon unreferenced object 0x3e09ba56000 (size 32112640): comm "swapon", pid 7852, jiffies 4294968787 (age 1490.770s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: __vmalloc_node_range+0x194/0x2d8 vzalloc+0x58/0x68 SyS_swapon+0xd60/0x12f8 system_call+0xd6/0x270 Turns out kmemleak is right. We now allocate the frontswap map depending on the kernel config (and no longer on the enablement) swapfile.c: [...] if (IS_ENABLED(CONFIG_FRONTSWAP)) frontswap_map = vzalloc(BITS_TO_LONGS(maxpages) * sizeof(long)); but later on this is passed along --> enable_swap_info(p, prio, swap_map, cluster_info, frontswap_map); and ignored if frontswap is disabled --> frontswap_init(p->type, frontswap_map); static inline void frontswap_init(unsigned type, unsigned long *map) { if (frontswap_enabled()) __frontswap_init(type, map); } Thing is, that frontswap map is never freed. The leakage is relatively not that bad, because swapon is an infrequent and privileged operation. However, if the first frontswap backend is registered after a swap type has been already enabled, it will WARN_ON in frontswap_register_ops() and frontswap will not be available for the swap type. Fix this by making sure the map is assigned by frontswap_init() as long as CONFIG_FRONTSWAP is enabled. Fixes: 8ea1d2a1985a ("mm, frontswap: convert frontswap_enabled to static key") Link: http://lkml.kernel.org/r/20161026134220.2566-1-vbabka@suse.cz Signed-off-by: Vlastimil Babka Reported-by: Christian Borntraeger Cc: Konrad Rzeszutek Wilk Cc: Boris Ostrovsky Cc: David Vrabel Cc: Juergen Gross Cc: "Kirill A. Shutemov" Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/frontswap.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/frontswap.h b/include/linux/frontswap.h index c46d2aa16d81..1d18af034554 100644 --- a/include/linux/frontswap.h +++ b/include/linux/frontswap.h @@ -106,8 +106,9 @@ static inline void frontswap_invalidate_area(unsigned type) static inline void frontswap_init(unsigned type, unsigned long *map) { - if (frontswap_enabled()) - __frontswap_init(type, map); +#ifdef CONFIG_FRONTSWAP + __frontswap_init(type, map); +#endif } #endif /* _LINUX_FRONTSWAP_H */ -- cgit v1.2.3 From c6c7d83b9c9e6a8b3e6d84c820ac61fbffc9e396 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Thu, 10 Nov 2016 10:46:26 -0800 Subject: Revert "console: don't prefer first registered if DT specifies stdout-path" This reverts commit 05fd007e4629 ("console: don't prefer first registered if DT specifies stdout-path"). The reverted commit changes existing behavior on which many ARM boards rely. Many ARM small-board-computers, like e.g. the Raspberry Pi have both a video output and a serial console. Depending on whether the user is using the device as a more regular computer; or as a headless device we need to have the console on either one or the other. Many users rely on the kernel behavior of the console being present on both outputs, before the reverted commit the console setup with no console= kernel arguments on an ARM board which sets stdout-path in dt would look like this: [root@localhost ~]# cat /proc/consoles ttyS0 -W- (EC p a) 4:64 tty0 -WU (E p ) 4:1 Where as after the reverted commit, it looks like this: [root@localhost ~]# cat /proc/consoles ttyS0 -W- (EC p a) 4:64 This commit reverts commit 05fd007e4629 ("console: don't prefer first registered if DT specifies stdout-path") restoring the original behavior. Fixes: 05fd007e4629 ("console: don't prefer first registered if DT specifies stdout-path") Link: http://lkml.kernel.org/r/20161104121135.4780-2-hdegoede@redhat.com Signed-off-by: Hans de Goede Cc: Paul Burton Cc: Rob Herring Cc: Frank Rowand Cc: Thorsten Leemhuis Cc: Greg Kroah-Hartman Cc: Tejun Heo Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/console.h | 6 ------ 1 file changed, 6 deletions(-) (limited to 'include') diff --git a/include/linux/console.h b/include/linux/console.h index 3672809234a7..d530c4627e54 100644 --- a/include/linux/console.h +++ b/include/linux/console.h @@ -173,12 +173,6 @@ static inline void console_sysfs_notify(void) #endif extern bool console_suspend_enabled; -#ifdef CONFIG_OF -extern void console_set_by_of(void); -#else -static inline void console_set_by_of(void) {} -#endif - /* Suspend and resume console messages over PM events */ extern void suspend_console(void); extern void resume_console(void); -- cgit v1.2.3 From d7c19b066dcf4bd19c4385e8065558d4e74f9e73 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Thu, 10 Nov 2016 10:46:44 -0800 Subject: mm: kmemleak: scan .data.ro_after_init Limit the number of kmemleak false positives by including .data.ro_after_init in memory scanning. To achieve this we need to add symbols for start and end of the section to the linker scripts. The problem was been uncovered by commit 56989f6d8568 ("genetlink: mark families as __ro_after_init"). Link: http://lkml.kernel.org/r/1478274173-15218-1-git-send-email-jakub.kicinski@netronome.com Reviewed-by: Catalin Marinas Signed-off-by: Jakub Kicinski Cc: Arnd Bergmann Cc: Cong Wang Cc: Johannes Berg Cc: Martin Schwidefsky Cc: Heiko Carstens Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-generic/sections.h | 3 +++ include/asm-generic/vmlinux.lds.h | 5 ++++- 2 files changed, 7 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/asm-generic/sections.h b/include/asm-generic/sections.h index af0254c09424..4df64a1fc09e 100644 --- a/include/asm-generic/sections.h +++ b/include/asm-generic/sections.h @@ -14,6 +14,8 @@ * [_sdata, _edata]: contains .data.* sections, may also contain .rodata.* * and/or .init.* sections. * [__start_rodata, __end_rodata]: contains .rodata.* sections + * [__start_data_ro_after_init, __end_data_ro_after_init]: + * contains data.ro_after_init section * [__init_begin, __init_end]: contains .init.* sections, but .init.text.* * may be out of this range on some architectures. * [_sinittext, _einittext]: contains .init.text.* sections @@ -31,6 +33,7 @@ extern char _data[], _sdata[], _edata[]; extern char __bss_start[], __bss_stop[]; extern char __init_begin[], __init_end[]; extern char _sinittext[], _einittext[]; +extern char __start_data_ro_after_init[], __end_data_ro_after_init[]; extern char _end[]; extern char __per_cpu_load[], __per_cpu_start[], __per_cpu_end[]; extern char __kprobes_text_start[], __kprobes_text_end[]; diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 30747960bc54..31e1d639abed 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -259,7 +259,10 @@ * own by defining an empty RO_AFTER_INIT_DATA. */ #ifndef RO_AFTER_INIT_DATA -#define RO_AFTER_INIT_DATA *(.data..ro_after_init) +#define RO_AFTER_INIT_DATA \ + __start_data_ro_after_init = .; \ + *(.data..ro_after_init) \ + __end_data_ro_after_init = .; #endif /* -- cgit v1.2.3