From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To: xen-devel@lists.xenproject.org, ross.lagerwall@citrix.com,
konrad@kernel.org, andrew.cooper3@citrix.com, mpohlack@amazon.de,
sasha.levin@oracle.com
Cc: Keir Fraser <keir@xen.org>,
Ian Jackson <ian.jackson@eu.citrix.com>,
Jan Beulich <jbeulich@suse.com>, Tim Deegan <tim@xen.org>
Subject: [PATCH v4 33/34] xsplice: Add support for shadow variables.
Date: Tue, 15 Mar 2016 13:56:55 -0400 [thread overview]
Message-ID: <1458064616-23101-34-git-send-email-konrad.wilk@oracle.com> (raw)
In-Reply-To: <1458064616-23101-1-git-send-email-konrad.wilk@oracle.com>
From: Ross Lagerwall <ross.lagerwall@citrix.com>
Shadow variables are a piece of infrastructure to be used by xsplice
modules. They are used to attach a new piece of data to an existing
structure in memory.
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
---
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Keir Fraser <keir@xen.org>
Cc: Tim Deegan <tim@xen.org>
v2: Add Copyright
---
---
xen/common/Makefile | 1 +
xen/common/xsplice_shadow.c | 109 ++++++++++++++++++++++++++++++++++++++++
xen/include/xen/xsplice_patch.h | 36 +++++++++++++
3 files changed, 146 insertions(+)
create mode 100644 xen/common/xsplice_shadow.c
diff --git a/xen/common/Makefile b/xen/common/Makefile
index 9b7fac7..200a544 100644
--- a/xen/common/Makefile
+++ b/xen/common/Makefile
@@ -62,6 +62,7 @@ obj-$(CONFIG_XENOPROF) += xenoprof.o
obj-y += xmalloc_tlsf.o
obj-$(CONFIG_XSPLICE) += xsplice.o
obj-$(CONFIG_XSPLICE) += xsplice_elf.o
+obj-$(CONFIG_XSPLICE) += xsplice_shadow.o
obj-bin-$(CONFIG_X86) += $(foreach n,decompress bunzip2 unxz unlzma unlzo unlz4 earlycpio,$(n).init.o)
diff --git a/xen/common/xsplice_shadow.c b/xen/common/xsplice_shadow.c
new file mode 100644
index 0000000..4196a0a
--- /dev/null
+++ b/xen/common/xsplice_shadow.c
@@ -0,0 +1,109 @@
+/*
+ * Copyright (C) 2016 Citrix Systems R&D Ltd.
+ */
+
+#include <xen/init.h>
+#include <xen/kernel.h>
+#include <xen/lib.h>
+#include <xen/list.h>
+#include <xen/spinlock.h>
+#include <xen/xsplice_patch.h>
+
+#define SHADOW_SLOTS 256
+struct hlist_head shadow_tbl[SHADOW_SLOTS];
+static DEFINE_SPINLOCK(shadow_lock);
+
+struct shadow_var {
+ struct hlist_node list; /* Linked to 'shadow_tbl' */
+ void *data;
+ const void *obj;
+ char var[16];
+};
+
+void *xsplice_shadow_alloc(const void *obj, const char *var, size_t size)
+{
+ struct shadow_var *shadow;
+ unsigned int slot;
+
+ shadow = xmalloc(struct shadow_var);
+ if ( !shadow )
+ return NULL;
+
+ shadow->obj = obj;
+ strlcpy(shadow->var, var, sizeof shadow->var);
+ shadow->data = xmalloc_bytes(size);
+ if ( !shadow->data )
+ {
+ xfree(shadow);
+ return NULL;
+ }
+
+ slot = (unsigned long)obj % SHADOW_SLOTS;
+ spin_lock(&shadow_lock);
+ hlist_add_head(&shadow->list, &shadow_tbl[slot]);
+ spin_unlock(&shadow_lock);
+
+ return shadow->data;
+}
+
+void xsplice_shadow_free(const void *obj, const char *var)
+{
+ struct shadow_var *entry, *shadow = NULL;
+ unsigned int slot;
+ struct hlist_node *next;
+
+ slot = (unsigned long)obj % SHADOW_SLOTS;
+
+ spin_lock(&shadow_lock);
+ hlist_for_each_entry(entry, next, &shadow_tbl[slot], list)
+ {
+ if ( entry->obj == obj &&
+ !strcmp(entry->var, var) )
+ {
+ shadow = entry;
+ break;
+ }
+ }
+ if (shadow)
+ {
+ hlist_del(&shadow->list);
+ xfree(shadow->data);
+ xfree(shadow);
+ }
+ spin_unlock(&shadow_lock);
+}
+
+void *xsplice_shadow_get(const void *obj, const char *var)
+{
+ struct shadow_var *entry;
+ unsigned int slot;
+ struct hlist_node *next;
+ void *ret = NULL;
+
+ slot = (unsigned long)obj % SHADOW_SLOTS;
+
+ spin_lock(&shadow_lock);
+ hlist_for_each_entry(entry, next, &shadow_tbl[slot], list)
+ {
+ if ( entry->obj == obj &&
+ !strcmp(entry->var, var) )
+ {
+ ret = entry->data;
+ break;
+ }
+ }
+
+ spin_unlock(&shadow_lock);
+ return ret;
+}
+
+static int __init xsplice_shadow_init(void)
+{
+ int i;
+
+ for ( i = 0; i < SHADOW_SLOTS; i++ )
+ INIT_HLIST_HEAD(&shadow_tbl[i]);
+
+ return 0;
+}
+__initcall(xsplice_shadow_init);
diff --git a/xen/include/xen/xsplice_patch.h b/xen/include/xen/xsplice_patch.h
index 19d3f76..e297fe1 100644
--- a/xen/include/xen/xsplice_patch.h
+++ b/xen/include/xen/xsplice_patch.h
@@ -56,4 +56,40 @@ typedef void (*xsplice_unloadcall_t)(void);
#define XSPLICE_UNLOAD_HOOK(_fn) \
xsplice_unloadcall_t __attribute__((weak)) xsplice_unload_data __section(".xsplice.hooks.unload") = _fn;
+
+/*
+ * The following definitions are to be used in patches. They are taken
+ * from kpatch.
+ */
+
+/*
+ * xsplice shadow variables
+ *
+ * These functions can be used to add new "shadow" fields to existing data
+ * structures. For example, to allocate a "newpid" variable associated with an
+ * instance of task_struct, and assign it a value of 1000:
+ *
+ * struct task_struct *tsk = current;
+ * int *newpid;
+ * newpid = xsplice_shadow_alloc(tsk, "newpid", sizeof(int));
+ * if (newpid)
+ * *newpid = 1000;
+ *
+ * To retrieve a pointer to the variable:
+ *
+ * struct task_struct *tsk = current;
+ * int *newpid;
+ * newpid = xsplice_shadow_get(tsk, "newpid");
+ * if (newpid)
+ * printk("task newpid = %d\n", *newpid); // prints "task newpid = 1000"
+ *
+ * To free it:
+ *
+ * xsplice_shadow_free(tsk, "newpid");
+ */
+
+void *xsplice_shadow_alloc(const void *obj, const char *var, size_t size);
+void xsplice_shadow_free(const void *obj, const char *var);
+void *xsplice_shadow_get(const void *obj, const char *var);
+
#endif /* __XEN_XSPLICE_PATCH_H__ */
--
2.5.0
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next prev parent reply other threads:[~2016-03-15 18:01 UTC|newest]
Thread overview: 124+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-15 17:56 [PATCH v4] xSplice v1 design and implementation Konrad Rzeszutek Wilk
2016-03-15 17:56 ` [PATCH v4 01/34] compat/x86: Remove unncessary #define Konrad Rzeszutek Wilk
2016-03-15 18:57 ` Andrew Cooper
2016-03-16 11:08 ` Jan Beulich
2016-03-17 0:44 ` Konrad Rzeszutek Wilk
2016-03-17 7:45 ` Jan Beulich
2016-03-15 17:56 ` [PATCH v4 02/34] libxc: Remove dead code (XENVER_capabilities) Konrad Rzeszutek Wilk
2016-03-15 18:04 ` Andrew Cooper
2016-03-15 18:08 ` Konrad Rzeszutek Wilk
2016-03-16 18:11 ` Wei Liu
2016-03-15 17:56 ` [PATCH v4 03/34] xsm/xen_version: Add XSM for the xen_version hypercall Konrad Rzeszutek Wilk
2016-03-18 11:55 ` Jan Beulich
2016-03-18 17:26 ` Konrad Rzeszutek Wilk
2016-03-21 11:22 ` Jan Beulich
2016-03-22 16:10 ` Konrad Rzeszutek Wilk
2016-03-22 17:54 ` Daniel De Graaf
2016-03-22 17:49 ` Daniel De Graaf
2016-03-24 15:34 ` anshul makkar
2016-03-24 19:19 ` Konrad Rzeszutek Wilk
2016-03-15 17:56 ` [PATCH v4 04/34] HYPERCALL_version_op. New hypercall mirroring XENVER_ but sane Konrad Rzeszutek Wilk
2016-03-15 18:29 ` Andrew Cooper
2016-03-15 20:19 ` Konrad Rzeszutek Wilk
2016-03-17 1:38 ` Konrad Rzeszutek Wilk
2016-03-17 14:28 ` Andrew Cooper
2016-03-18 12:36 ` Jan Beulich
2016-03-18 19:22 ` Konrad Rzeszutek Wilk
2016-03-21 12:45 ` Jan Beulich
2016-03-22 15:52 ` Konrad Rzeszutek Wilk
2016-03-22 16:06 ` Jan Beulich
2016-03-22 18:57 ` Konrad Rzeszutek Wilk
2016-03-22 19:28 ` Andrew Cooper
2016-03-22 20:39 ` Konrad Rzeszutek Wilk
2016-03-23 8:56 ` Jan Beulich
2016-03-24 2:37 ` Konrad Rzeszutek Wilk
2016-03-24 9:15 ` Jan Beulich
2016-03-24 11:39 ` Konrad Rzeszutek Wilk
2016-03-22 17:51 ` Daniel De Graaf
2016-03-15 17:56 ` [PATCH v4 05/34] libxc/libxl/python/xenstat: Use new XEN_VERSION_OP hypercall Konrad Rzeszutek Wilk
2016-03-15 18:45 ` Andrew Cooper
2016-03-16 12:31 ` George Dunlap
2016-03-16 18:11 ` Wei Liu
2016-03-17 1:08 ` Konrad Rzeszutek Wilk
2016-03-15 17:56 ` [PATCH v4 06/34] x86/arm: Add BUGFRAME_NR define and BUILD checks Konrad Rzeszutek Wilk
2016-03-15 18:54 ` Andrew Cooper
2016-03-16 11:49 ` Julien Grall
2016-03-18 12:40 ` Jan Beulich
2016-03-18 19:59 ` Konrad Rzeszutek Wilk
2016-03-21 12:49 ` Jan Beulich
2016-03-22 15:39 ` Konrad Rzeszutek Wilk
2016-03-22 15:58 ` Jan Beulich
2016-03-15 17:56 ` [PATCH v4 07/34] arm/x86: Use struct virtual_region to do bug, symbol, and (x86) exception tables Konrad Rzeszutek Wilk
2016-03-15 19:24 ` Andrew Cooper
2016-03-15 19:34 ` Konrad Rzeszutek Wilk
2016-03-15 19:51 ` Andrew Cooper
2016-03-15 20:02 ` Andrew Cooper
2016-03-16 10:33 ` Jan Beulich
2016-03-18 13:07 ` Jan Beulich
2016-03-22 20:18 ` Konrad Rzeszutek Wilk
2016-03-23 8:19 ` Jan Beulich
2016-03-23 11:17 ` Julien Grall
2016-03-23 11:21 ` Jan Beulich
2016-03-24 2:49 ` Konrad Rzeszutek Wilk
2016-03-24 9:20 ` Jan Beulich
2016-03-15 17:56 ` [PATCH v4 08/34] vmap: Make the while loop less fishy Konrad Rzeszutek Wilk
2016-03-15 19:33 ` Andrew Cooper
2016-03-17 11:49 ` Jan Beulich
2016-03-17 14:37 ` Andrew Cooper
2016-03-17 15:30 ` Jan Beulich
2016-03-17 16:06 ` Ian Jackson
2016-03-17 11:48 ` Jan Beulich
2016-03-17 16:08 ` Ian Jackson
2016-03-21 12:04 ` George Dunlap
2016-03-21 13:26 ` Jan Beulich
2016-03-21 14:22 ` George Dunlap
2016-03-21 15:05 ` Jan Beulich
2016-03-15 17:56 ` [PATCH v4 09/34] vmap: ASSERT on NULL Konrad Rzeszutek Wilk
2016-03-15 17:56 ` [PATCH v4 10/34] vmap: Add vmalloc_cb and vfree_cb Konrad Rzeszutek Wilk
2016-03-18 13:20 ` Jan Beulich
2016-03-15 17:56 ` [PATCH v4 11/34] xsplice: Design document Konrad Rzeszutek Wilk
2016-03-23 11:18 ` Jan Beulich
2016-03-23 20:12 ` Konrad Rzeszutek Wilk
2016-03-23 20:21 ` Konrad Rzeszutek Wilk
2016-03-24 3:15 ` Konrad Rzeszutek Wilk
2016-03-24 9:32 ` Jan Beulich
2016-03-15 17:56 ` [PATCH v4 12/34] xen/xsplice: Hypervisor implementation of XEN_XSPLICE_op Konrad Rzeszutek Wilk
2016-03-16 12:12 ` Julien Grall
2016-03-16 19:58 ` Konrad Rzeszutek Wilk
2016-03-23 13:51 ` Jan Beulich
2016-03-24 3:13 ` Konrad Rzeszutek Wilk
2016-03-24 9:29 ` Jan Beulich
2016-03-15 17:56 ` [PATCH v4 13/34] libxc: Implementation of XEN_XSPLICE_op in libxc Konrad Rzeszutek Wilk
2016-03-16 18:12 ` Wei Liu
2016-03-16 20:36 ` Konrad Rzeszutek Wilk
2016-03-15 17:56 ` [PATCH v4 14/34] xen-xsplice: Tool to manipulate xsplice payloads Konrad Rzeszutek Wilk
2016-03-16 18:12 ` Wei Liu
2016-03-15 17:56 ` [PATCH v4 15/34] xsplice: Add helper elf routines Konrad Rzeszutek Wilk
2016-03-15 17:56 ` [PATCH v4 16/34] xsplice: Implement payload loading Konrad Rzeszutek Wilk
2016-03-22 17:25 ` Konrad Rzeszutek Wilk
2016-03-15 17:56 ` [PATCH v4 17/34] xsplice: Implement support for applying/reverting/replacing patches Konrad Rzeszutek Wilk
2016-03-15 17:56 ` [PATCH v4 18/34] x86/xen_hello_world.xsplice: Test payload for patching 'xen_extra_version' Konrad Rzeszutek Wilk
2016-03-15 17:56 ` [PATCH v4 19/34] xsplice, symbols: Implement symbol name resolution on address Konrad Rzeszutek Wilk
2016-03-15 17:56 ` [PATCH v4 20/34] x86, xsplice: Print payload's symbol name and payload name in backtraces Konrad Rzeszutek Wilk
2016-03-15 17:56 ` [PATCH v4 21/34] xsplice: Add .xsplice.hooks functions and test-case Konrad Rzeszutek Wilk
2016-03-15 17:56 ` [PATCH v4 22/34] xsplice: Add support for bug frames Konrad Rzeszutek Wilk
2016-03-15 17:56 ` [PATCH v4 23/34] xsplice: Add support for exception tables Konrad Rzeszutek Wilk
2016-03-15 17:56 ` [PATCH v4 24/34] xsplice: Add support for alternatives Konrad Rzeszutek Wilk
2016-03-15 17:56 ` [PATCH v4 25/34] build_id: Provide ld-embedded build-ids Konrad Rzeszutek Wilk
2016-03-16 18:34 ` Julien Grall
2016-03-16 21:02 ` Konrad Rzeszutek Wilk
2016-03-17 1:12 ` Konrad Rzeszutek Wilk
2016-03-17 11:08 ` Julien Grall
2016-03-17 13:39 ` Konrad Rzeszutek Wilk
2016-03-15 17:56 ` [PATCH v4 26/34] HYPERCALL_version_op: Add VERSION_OP_build_id to retrieve build-id Konrad Rzeszutek Wilk
2016-03-15 17:56 ` [PATCH v4 27/34] libxl: info: Display build_id of the hypervisor using XEN_VERSION_OP_build_id Konrad Rzeszutek Wilk
2016-03-16 18:12 ` Wei Liu
2016-03-15 17:56 ` [PATCH v4 28/34] xsplice: Print build_id in keyhandler and on bootup Konrad Rzeszutek Wilk
2016-03-15 17:56 ` [PATCH v4 29/34] xsplice: Stacking build-id dependency checking Konrad Rzeszutek Wilk
2016-03-15 17:56 ` [PATCH v4 30/34] xsplice/xen_replace_world: Test-case for XSPLICE_ACTION_REPLACE Konrad Rzeszutek Wilk
2016-03-15 17:56 ` [PATCH v4 31/34] xsplice: Print dependency and payloads build_id in the keyhandler Konrad Rzeszutek Wilk
2016-03-15 17:56 ` [PATCH v4 32/34] xsplice: Prevent duplicate payloads from being loaded Konrad Rzeszutek Wilk
2016-03-15 17:56 ` Konrad Rzeszutek Wilk [this message]
2016-03-15 17:56 ` [PATCH v4 34/34] MAINTAINERS/xsplice: Add myself and Ross as the maintainers Konrad Rzeszutek Wilk
2016-03-16 11:10 ` Jan Beulich
2016-03-17 0:44 ` Konrad Rzeszutek Wilk
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