diff mbox series

[RFC,v4,07/15] Define a new DT_FLAGS_1 flag - DF_1_UNIQUE

Message ID	e14a7feb4ab15b13fec7b597655f69159b6cad86.1585588166.git.vivek@collabora.com
State	Superseded
Headers	DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 7F9743876059 sender: vivek) by bhuna.collabora.co.uk (Postfix) with ESMTPSA id B18A92966E6; Mon, 30 Mar 2020 18:43:57 +0100 (BST) From: =?utf-8?q?Vivek_Das=C2=A0Mohapatra?= <vivek@collabora.com> To: vivek@etla.org, libc-alpha@sourceware.org Subject: [RFC][PATCH v4 07/15] Define a new DT_FLAGS_1 flag - DF_1_UNIQUE Date: Mon, 30 Mar 2020 18:43:41 +0100 Message-Id: <e14a7feb4ab15b13fec7b597655f69159b6cad86.1585588166.git.vivek@collabora.com> In-Reply-To: <cover.1585588166.git.vivek@collabora.com> References: <cover.1585588166.git.vivek@collabora.com> In-Reply-To: <cover.1585588166.git.vivek@collabora.com> References: <cover.1585588166.git.vivek@collabora.com> Precedence: list
Series	Proof-of-Concept implementation of RTLD_SHARED for dlmopen \| [RFC,v4,00/15] Proof-of-Concept implementation of RTLD_SHARED for dlmopen [RFC,v4,01/15] Declare and describe the dlmopen RTLD_SHARED flag [RFC,v4,02/15] include/link.h: Update the link_map struct to allow proxies [RFC,v4,03/15] elf/dl-object.c: Implement a helper function to proxy link_map entries [RFC,v4,04/15] elf/dl-load.c, elf-dl-open.c: Implement RTLD_SHARED dlmopen proxying [RFC,v4,05/15] elf/dl-fini.c: Handle proxy link_map entries in the shutdown path [RFC,v4,06/15] elf/dl-init.c: Skip proxied link map entries in the dl init path [RFC,v4,07/15] Define a new DT_FLAGS_1 flag - DF_1_UNIQUE [RFC,v4,08/15] Abstract the loaded-DSO search code into a private helper function [RFC,v4,09/15] Compare loaded DSOs by file ID and check for DF_1_UNIQUE [RFC,v4,10/15] Use the new DSO finder helper function since we have it [RFC,v4,11/15] Use the DSO search helper to check for preloaded DF_1_UNIQUE DSOs [RFC,v4,12/15] When loading new DSOs into alternate namespaces check for DF_1_UNIQUE [RFC,v4,13/15] Suppress inter-namespace DSO sharing for audit libraries [RFC,v4,14/15] dlsym, dlvsym should be able to look up symbols via DSO proxies [RFC,v4,15/15] Add the DT_FLAGS_1 DF_1_UNIQUE flag to the glibc cluster

Commit Message

Vivek Dasmohapatra March 30, 2020, 5:43 p.m. UTC

  We expect this flag to be set on ELF DSOs that should only
ever have one instance across all link map namespaces.

libc and its constituent DSOs should have this flag set.
---
 elf/elf.h     | 1 +
 include/elf.h | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff mbox series

Patch

diff --git a/elf/elf.h b/elf/elf.h
index 2549a177d6..e0876b5701 100644
--- a/elf/elf.h
+++ b/elf/elf.h
@@ -997,6 +997,7 @@  typedef struct
 #define	DF_1_KMOD       0x10000000
 #define	DF_1_WEAKFILTER 0x20000000
 #define	DF_1_NOCOMMON   0x40000000
+#define	DF_1_UNIQUE     0x80000000      /* Object should exist at most once */
 
 /* Flags for the feature selection in DT_FEATURE_1.  */
 #define DTF_1_PARINIT	0x00000001
diff --git a/include/elf.h b/include/elf.h
index 14ed67ff67..ebcae81522 100644
--- a/include/elf.h
+++ b/include/elf.h
@@ -23,7 +23,7 @@ 
 # endif
 # define DT_1_SUPPORTED_MASK \
    (DF_1_NOW | DF_1_NODELETE | DF_1_INITFIRST | DF_1_NOOPEN \
-    | DF_1_ORIGIN | DF_1_NODEFLIB | DF_1_PIE)
+    | DF_1_ORIGIN | DF_1_NODEFLIB | DF_1_PIE | DF_1_UNIQUE)
 
 #endif /* !_ISOMAC */
 #endif /* elf.h */