The patch titled
coredump masking: documentation for /proc/pid/coredump_filter
has been removed from the -mm tree. Its filename was
coredump-masking-documentation-for-proc-pid-coredump_filter.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
Subject: coredump masking: documentation for /proc/pid/coredump_filter
From: "Kawai, Hidehiro" <hidehiro.kawai.ez@xxxxxxxxxxx>
This patch adds the documentation for /proc/<pid>/coredump_filter.
Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@xxxxxxxxxxx>
Cc: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
Cc: Hugh Dickins <hugh@xxxxxxxxxxx>
Cc: Nick Piggin <nickpiggin@xxxxxxxxxxxx>
Cc: "Randy.Dunlap" <rdunlap@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/filesystems/proc.txt | 38 +++++++++++++++++++++++++++
1 file changed, 38 insertions(+)
diff -puN Documentation/filesystems/proc.txt~coredump-masking-documentation-for-proc-pid-coredump_filter Documentation/filesystems/proc.txt
--- a/Documentation/filesystems/proc.txt~coredump-masking-documentation-for-proc-pid-coredump_filter
+++ a/Documentation/filesystems/proc.txt
@@ -42,6 +42,7 @@ Table of Contents
2.12 /proc/<pid>/oom_adj - Adjust the oom-killer score
2.13 /proc/<pid>/oom_score - Display current oom-killer score
2.14 /proc/<pid>/io - Display the IO accounting fields
+ 2.15 /proc/<pid>/coredump_filter - Core dump filtering settings
------------------------------------------------------------------------------
Preface
@@ -2184,4 +2185,41 @@ those 64-bit counters, process A could s
More information about this can be found within the taskstats documentation in
Documentation/accounting.
+2.15 /proc/<pid>/coredump_filter - Core dump filtering settings
+---------------------------------------------------------------
+When a process is dumped, all anonymous memory is written to a core file as
+long as the size of the core file isn't limited. But sometimes we don't want
+to dump some memory segments, for example, huge shared memory. Conversely,
+sometimes we want to save file-backed memory segments into a core file, not
+only the individual files.
+
+/proc/<pid>/coredump_filter allows you to customize which memory segments
+will be dumped when the <pid> process is dumped. coredump_filter is a bitmask
+of memory types. If a bit of the bitmask is set, memory segments of the
+corresponding memory type are dumped, otherwise they are not dumped.
+
+The following 4 memory types are supported:
+ - (bit 0) anonymous private memory
+ - (bit 1) anonymous shared memory
+ - (bit 2) file-backed private memory
+ - (bit 3) file-backed shared memory
+
+ Note that MMIO pages such as frame buffer are never dumped and vDSO pages
+ are always dumped regardless of the bitmask status.
+
+Default value of coredump_filter is 0x3; this means all anonymous memory
+segments are dumped.
+
+If you don't want to dump all shared memory segments attached to pid 1234,
+write 1 to the process's proc file.
+
+ $ echo 0x1 > /proc/1234/coredump_filter
+
+When a new process is created, the process inherits the bitmask status from its
+parent. It is useful to set up coredump_filter before the program runs.
+For example:
+
+ $ echo 0x7 > /proc/self/coredump_filter
+ $ ./some_program
+
------------------------------------------------------------------------------
_
Patches currently in -mm which might be from hidehiro.kawai.ez@xxxxxxxxxxx are
origin.patch
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