3.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: Helge Deller <[email protected]> commit ae249b5fa27f9fba25aa59664d4338efc2dd2394 upstream. With CONFIG_DISCONTIGMEM=y and multiple physical memory areas, cat /proc/kpageflags triggers this kernel bug: kernel BUG at arch/parisc/include/asm/mmzone.h:50! CPU: 2 PID: 7848 Comm: cat Tainted: G D W 3.10.0-rc3-64bit #44 IAOQ[0]: kpageflags_read0x128/0x238 IAOQ[1]: kpageflags_read0x12c/0x238 RP(r2): proc_reg_read0xbc/0x130 Backtrace: [<00000000402ca2d4>] proc_reg_read0xbc/0x130 [<0000000040235bcc>] vfs_read0xc4/0x1d0 [<0000000040235f0c>] SyS_read0x94/0xf0 [<0000000040105fc0>] syscall_exit0x0/0x14 kpageflags_read() walks through the whole memory, even if some memory areas are physically not available. So, we should better not BUG on an unavailable pfn in pfn_to_nid() but just return the expected value -1 or 0. Signed-off-by: Helge Deller <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- arch/parisc/include/asm/mmzone.h | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) --- a/arch/parisc/include/asm/mmzone.h +++ b/arch/parisc/include/asm/mmzone.h @@ -39,17 +39,14 @@ extern unsigned char pfnnid_map[PFNNID_M static inline int pfn_to_nid(unsigned long pfn) { unsigned int i; - unsigned char r; if (unlikely(pfn_is_io(pfn))) return 0; i = pfn >> PFNNID_SHIFT; BUG_ON(i >= ARRAY_SIZE(pfnnid_map)); - r = pfnnid_map[i]; - BUG_ON(r == 0xff); - return (int)r; + return (int)pfnnid_map[i]; } static inline int pfn_valid(int pfn) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
