From accb61fe7bb0f5c2a4102239e4981650f9048519 Mon Sep 17 00:00:00 2001 From: Jason Baron Date: Fri, 23 Mar 2012 15:02:51 -0700 Subject: coredump: add VM_NODUMP, MADV_NODUMP, MADV_CLEAR_NODUMP Since we no longer need the VM_ALWAYSDUMP flag, let's use the freed bit for 'VM_NODUMP' flag. The idea is is to add a new madvise() flag: MADV_DONTDUMP, which can be set by applications to specifically request memory regions which should not dump core. The specific application I have in mind is qemu: we can add a flag there that wouldn't dump all of guest memory when qemu dumps core. This flag might also be useful for security sensitive apps that want to absolutely make sure that parts of memory are not dumped. To clear the flag use: MADV_DODUMP. [akpm@linux-foundation.org: s/MADV_NODUMP/MADV_DONTDUMP/, s/MADV_CLEAR_NODUMP/MADV_DODUMP/, per Roland] [akpm@linux-foundation.org: fix up the architectures which broke] Signed-off-by: Jason Baron Acked-by: Roland McGrath Cc: Chris Metcalf Cc: Avi Kivity Cc: Ralf Baechle Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Matt Turner Cc: "James E.J. Bottomley" Cc: Helge Deller Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-generic/mman-common.h | 4 ++++ include/linux/mm.h | 1 + 2 files changed, 5 insertions(+) (limited to 'include') diff --git a/include/asm-generic/mman-common.h b/include/asm-generic/mman-common.h index 787abbb6d867..d030d2c2647a 100644 --- a/include/asm-generic/mman-common.h +++ b/include/asm-generic/mman-common.h @@ -48,6 +48,10 @@ #define MADV_HUGEPAGE 14 /* Worth backing with hugepages */ #define MADV_NOHUGEPAGE 15 /* Not worth backing with hugepages */ +#define MADV_DONTDUMP 16 /* Explicity exclude from the core dump, + overrides the coredump filter bits */ +#define MADV_DODUMP 17 /* Clear the MADV_NODUMP flag */ + /* compatibility flags */ #define MAP_FILE 0 diff --git a/include/linux/mm.h b/include/linux/mm.h index 2de2ddba51d4..a6fabdfd34c5 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -111,6 +111,7 @@ extern unsigned int kobjsize(const void *objp); #define VM_HUGEPAGE 0x01000000 /* MADV_HUGEPAGE marked this vma */ #endif #define VM_INSERTPAGE 0x02000000 /* The vma has had "vm_insert_page()" done on it */ +#define VM_NODUMP 0x04000000 /* Do not include in the core dump */ #define VM_CAN_NONLINEAR 0x08000000 /* Has ->fault & does nonlinear pages */ #define VM_MIXEDMAP 0x10000000 /* Can contain "struct page" and pure PFN pages */ -- cgit v1.2.3