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Date: Tue, 10 Sep 2013 11:31:46 -0400
From: Boris Ostrovsky <boris.ostrovsky@...cle.com>
To: xen-devel@...ts.xen.org
Cc: konrad.wilk@...cle.com, david.vrabel@...rix.com, JBeulich@...e.com,
linux-kernel@...r.kernel.org,
Boris Ostrovsky <boris.ostrovsky@...cle.com>
Subject: [PATCH v1 1/5] xen: xensyms support
Export Xen symbols to dom0 via /proc/xen/xensyms (similar to /proc/kallsyms).
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@...cle.com>
---
drivers/xen/Kconfig | 5 ++
drivers/xen/xenfs/Makefile | 1 +
drivers/xen/xenfs/super.c | 3 +
drivers/xen/xenfs/xenfs.h | 1 +
drivers/xen/xenfs/xensyms.c | 170 +++++++++++++++++++++++++++++++++++++++
include/xen/interface/platform.h | 21 +++++
6 files changed, 201 insertions(+)
create mode 100644 drivers/xen/xenfs/xensyms.c
diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
index 9e02d60..a21fce9 100644
--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -242,4 +242,9 @@ config XEN_MCE_LOG
config XEN_HAVE_PVMMU
bool
+config XEN_SYMS
+ bool "Xen symbols"
+ depends on XEN_DOM0 && XENFS && KALLSYMS
+ default y
+
endmenu
diff --git a/drivers/xen/xenfs/Makefile b/drivers/xen/xenfs/Makefile
index b019865..1a83010 100644
--- a/drivers/xen/xenfs/Makefile
+++ b/drivers/xen/xenfs/Makefile
@@ -2,3 +2,4 @@ obj-$(CONFIG_XENFS) += xenfs.o
xenfs-y = super.o
xenfs-$(CONFIG_XEN_DOM0) += xenstored.o
+xenfs-$(CONFIG_XEN_SYMS) += xensyms.o
diff --git a/drivers/xen/xenfs/super.c b/drivers/xen/xenfs/super.c
index 06092e0..8559a71 100644
--- a/drivers/xen/xenfs/super.c
+++ b/drivers/xen/xenfs/super.c
@@ -57,6 +57,9 @@ static int xenfs_fill_super(struct super_block *sb, void *data, int silent)
{ "privcmd", &xen_privcmd_fops, S_IRUSR|S_IWUSR },
{ "xsd_kva", &xsd_kva_file_ops, S_IRUSR|S_IWUSR},
{ "xsd_port", &xsd_port_file_ops, S_IRUSR|S_IWUSR},
+#ifdef CONFIG_XEN_SYMS
+ { "xensyms", &xensyms_ops, S_IRUSR},
+#endif
{""},
};
diff --git a/drivers/xen/xenfs/xenfs.h b/drivers/xen/xenfs/xenfs.h
index 6b80c77..2c5934e 100644
--- a/drivers/xen/xenfs/xenfs.h
+++ b/drivers/xen/xenfs/xenfs.h
@@ -3,5 +3,6 @@
extern const struct file_operations xsd_kva_file_ops;
extern const struct file_operations xsd_port_file_ops;
+extern const struct file_operations xensyms_ops;
#endif /* _XENFS_XENBUS_H */
diff --git a/drivers/xen/xenfs/xensyms.c b/drivers/xen/xenfs/xensyms.c
new file mode 100644
index 0000000..e3301f0
--- /dev/null
+++ b/drivers/xen/xenfs/xensyms.c
@@ -0,0 +1,170 @@
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/seq_file.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/proc_fs.h>
+#include <linux/slab.h>
+#include <xen/interface/platform.h>
+#include <asm/xen/hypercall.h>
+#include <xen/xen-ops.h>
+#include "xenfs.h"
+
+
+struct xensyms_state {
+ struct xenpf_symdata symdata;
+ ssize_t off;
+};
+
+/* Grab next output page from the hypervisor */
+static int xensyms_next_page(struct xensyms_state *state)
+{
+ int ret;
+ struct xen_platform_op op;
+
+ op.cmd = XENPF_get_symbols;
+ op.u.symdata = state->symdata;
+
+ ret = HYPERVISOR_dom0_op(&op);
+ if (ret < 0)
+ return ret;
+ if (ret == 0)
+ /* End of symbols */
+ return 1;
+
+ state->symdata = op.u.symdata;
+ state->off = 0;
+
+ return 0;
+}
+
+static void *xensyms_start(struct seq_file *m, loff_t *pos)
+{
+ struct xensyms_state *state = (struct xensyms_state *)m->private;
+
+ if (state->off == UINT_MAX) {
+ if (xensyms_next_page(state))
+ return NULL;
+ }
+
+ return m->private;
+}
+
+static void *xensyms_next(struct seq_file *m, void *p, loff_t *pos)
+{
+ struct xensyms_state *state = (struct xensyms_state *)m->private;
+ unsigned int str_len, next_off;
+
+ str_len = strlen(&state->symdata.buf[state->off]) + 1;
+ next_off = state->off + str_len;
+
+ /* If there is no more data on this page then ask Xen for more */
+ if (next_off >= XENSYMS_SZ || state->symdata.buf[next_off] == 0) {
+ if (xensyms_next_page(state))
+ return NULL;
+ } else
+ state->off = next_off;
+
+ return p;
+}
+
+static int xensyms_show(struct seq_file *m, void *p)
+{
+ struct xensyms_state *state = (struct xensyms_state *)m->private;
+
+ seq_printf(m, "%s", &state->symdata.buf[state->off]);
+
+ return 0;
+}
+
+static void xensyms_stop(struct seq_file *m, void *p)
+{
+}
+
+static const struct seq_operations xensyms_seq_ops = {
+ .start = xensyms_start,
+ .next = xensyms_next,
+ .show = xensyms_show,
+ .stop = xensyms_stop,
+};
+
+static int xensyms_open(struct inode *inode, struct file *file)
+{
+ int ret;
+ struct xensyms_state *state;
+ struct seq_file *m;
+
+ ret = seq_open_private(file, &xensyms_seq_ops,
+ sizeof(struct xensyms_state));
+ if (ret)
+ return ret;
+
+ m = file->private_data;
+ state = (struct xensyms_state *)m->private;
+ state->symdata.buf = kmalloc(XENSYMS_SZ, GFP_KERNEL);
+ if (!state->symdata.buf) {
+ (void)seq_release_private(inode, file);
+ return -ENOMEM;
+ }
+
+ /* Force first page fetch in xensyms_start() */
+ state->off = UINT_MAX;
+
+ state->symdata.xen_offset = 0;
+ state->symdata.xen_symnum = 0;
+
+ return 0;
+}
+
+static int xensyms_release(struct inode *inode, struct file *file)
+{
+ struct seq_file *m = file->private_data;
+ struct xensyms_state *state = (struct xensyms_state *)m->private;
+
+ kfree(state->symdata.buf);
+ return seq_release_private(inode, file);
+}
+
+static loff_t xensyms_lseek(struct file *file, loff_t offset, int whence)
+{
+ loff_t ret;
+ struct seq_file *m = file->private_data;
+ struct xensyms_state *state = (struct xensyms_state *)m->private;
+
+ /*
+ * lseek is rather limited in what it can do here since the file
+ * is stored in compressed form. Typically it is only used to
+ * seek to the beginning of the file by 'more' and the like
+ * Getting it to work correctly maybe a TODO (broken for Linux
+ * kallsyms too)
+ */
+ if (whence != SEEK_SET)
+ return -EINVAL;
+
+ state->symdata.xen_offset = 0;
+ state->symdata.xen_symnum = 0;
+ state->off = UINT_MAX;
+
+ ret = seq_lseek(file, offset, whence);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * Advance pointers to next string (seq_read() will flush
+ * remainder of current string to user on next read).
+ * Note that we are guaranteed not to cross page boundary here
+ * since only whole strings are placed onto the page by Xen.
+ */
+ if (state->off != UINT_MAX && state->symdata.buf[state->off] != 0)
+ state->off += strlen(&state->symdata.buf[state->off]) + 1;
+
+ return ret;
+}
+
+
+const struct file_operations xensyms_ops = {
+ .open = xensyms_open,
+ .read = seq_read,
+ .llseek = xensyms_lseek,
+ .release = xensyms_release
+};
diff --git a/include/xen/interface/platform.h b/include/xen/interface/platform.h
index c57d5f6..ecaaa08a04 100644
--- a/include/xen/interface/platform.h
+++ b/include/xen/interface/platform.h
@@ -351,6 +351,26 @@ struct xenpf_core_parking {
};
DEFINE_GUEST_HANDLE_STRUCT(xenpf_core_parking);
+#define XENPF_get_symbols 61
+
+#define XENSYMS_SZ 4096
+struct xenpf_symdata {
+ /*
+ * offset into Xen's symbol data and symbol number from
+ * last call. Used only by Xen.
+ */
+ uint64_t xen_offset;
+ uint64_t xen_symnum;
+
+ /*
+ * Symbols data, formatted similar to /proc/kallsyms:
+ * <address> <type> <name>
+ */
+ GUEST_HANDLE(char) buf;
+};
+DEFINE_GUEST_HANDLE_STRUCT(xenpf_symdata);
+
+
struct xen_platform_op {
uint32_t cmd;
uint32_t interface_version; /* XENPF_INTERFACE_VERSION */
@@ -371,6 +391,7 @@ struct xen_platform_op {
struct xenpf_cpu_hotadd cpu_add;
struct xenpf_mem_hotadd mem_add;
struct xenpf_core_parking core_parking;
+ struct xenpf_symdata symdata;
uint8_t pad[128];
} u;
};
--
1.8.1.4
--
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