From a11f4f0a4e18b4bdc7d5e36438711e038b7a1f74 Mon Sep 17 00:00:00 2001 From: Boris Ostrovsky Date: Mon, 10 Aug 2015 16:34:32 -0400 Subject: xen: xensyms support Export Xen symbols to dom0 via /proc/xen/xensyms (similar to /proc/kallsyms). Signed-off-by: Boris Ostrovsky Reviewed-by: David Vrabel Signed-off-by: David Vrabel --- drivers/xen/Kconfig | 8 +++ drivers/xen/xenfs/Makefile | 1 + drivers/xen/xenfs/super.c | 3 + drivers/xen/xenfs/xenfs.h | 1 + drivers/xen/xenfs/xensyms.c | 152 +++++++++++++++++++++++++++++++++++++++ include/xen/interface/platform.h | 18 +++++ 6 files changed, 183 insertions(+) create mode 100644 drivers/xen/xenfs/xensyms.c diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig index 7cd226da15fe..936760455dd5 100644 --- a/drivers/xen/Kconfig +++ b/drivers/xen/Kconfig @@ -280,4 +280,12 @@ config XEN_ACPI def_bool y depends on X86 && ACPI +config XEN_SYMS + bool "Xen symbols" + depends on X86 && XEN_DOM0 && XENFS + default y if KALLSYMS + help + Exports hypervisor symbols (along with their types and addresses) via + /proc/xen/xensyms file, similar to /proc/kallsyms + endmenu diff --git a/drivers/xen/xenfs/Makefile b/drivers/xen/xenfs/Makefile index b019865fcc56..1a83010ddffa 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 06092e0fe8ce..8559a71f36b1 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 6b80c7779c02..2c5934ea9b1e 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 000000000000..f8b12856753f --- /dev/null +++ b/drivers/xen/xenfs/xensyms.c @@ -0,0 +1,152 @@ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "xenfs.h" + + +#define XEN_KSYM_NAME_LEN 127 /* Hypervisor may have different name length */ + +struct xensyms { + struct xen_platform_op op; + char *name; + uint32_t namelen; +}; + +/* Grab next output page from the hypervisor */ +static int xensyms_next_sym(struct xensyms *xs) +{ + int ret; + struct xenpf_symdata *symdata = &xs->op.u.symdata; + uint64_t symnum; + + memset(xs->name, 0, xs->namelen); + symdata->namelen = xs->namelen; + + symnum = symdata->symnum; + + ret = HYPERVISOR_dom0_op(&xs->op); + if (ret < 0) + return ret; + + /* + * If hypervisor's symbol didn't fit into the buffer then allocate + * a larger buffer and try again. + */ + if (unlikely(symdata->namelen > xs->namelen)) { + kfree(xs->name); + + xs->namelen = symdata->namelen; + xs->name = kzalloc(xs->namelen, GFP_KERNEL); + if (!xs->name) + return -ENOMEM; + + set_xen_guest_handle(symdata->name, xs->name); + symdata->symnum--; /* Rewind */ + + ret = HYPERVISOR_dom0_op(&xs->op); + if (ret < 0) + return ret; + } + + if (symdata->symnum == symnum) + /* End of symbols */ + return 1; + + return 0; +} + +static void *xensyms_start(struct seq_file *m, loff_t *pos) +{ + struct xensyms *xs = (struct xensyms *)m->private; + + xs->op.u.symdata.symnum = *pos; + + if (xensyms_next_sym(xs)) + return NULL; + + return m->private; +} + +static void *xensyms_next(struct seq_file *m, void *p, loff_t *pos) +{ + struct xensyms *xs = (struct xensyms *)m->private; + + xs->op.u.symdata.symnum = ++(*pos); + + if (xensyms_next_sym(xs)) + return NULL; + + return p; +} + +static int xensyms_show(struct seq_file *m, void *p) +{ + struct xensyms *xs = (struct xensyms *)m->private; + struct xenpf_symdata *symdata = &xs->op.u.symdata; + + seq_printf(m, "%016llx %c %s\n", symdata->address, + symdata->type, xs->name); + + 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) +{ + struct seq_file *m; + struct xensyms *xs; + int ret; + + ret = seq_open_private(file, &xensyms_seq_ops, + sizeof(struct xensyms)); + if (ret) + return ret; + + m = file->private_data; + xs = (struct xensyms *)m->private; + + xs->namelen = XEN_KSYM_NAME_LEN + 1; + xs->name = kzalloc(xs->namelen, GFP_KERNEL); + if (!xs->name) { + seq_release_private(inode, file); + return -ENOMEM; + } + set_xen_guest_handle(xs->op.u.symdata.name, xs->name); + xs->op.cmd = XENPF_get_symbol; + xs->op.u.symdata.namelen = xs->namelen; + + return 0; +} + +static int xensyms_release(struct inode *inode, struct file *file) +{ + struct seq_file *m = file->private_data; + struct xensyms *xs = (struct xensyms *)m->private; + + kfree(xs->name); + return seq_release_private(inode, file); +} + +const struct file_operations xensyms_ops = { + .open = xensyms_open, + .read = seq_read, + .llseek = seq_lseek, + .release = xensyms_release +}; diff --git a/include/xen/interface/platform.h b/include/xen/interface/platform.h index 5cc49ea8d840..8e035871360e 100644 --- a/include/xen/interface/platform.h +++ b/include/xen/interface/platform.h @@ -474,6 +474,23 @@ struct xenpf_core_parking { }; DEFINE_GUEST_HANDLE_STRUCT(xenpf_core_parking); +#define XENPF_get_symbol 63 +struct xenpf_symdata { + /* IN/OUT variables */ + uint32_t namelen; /* size of 'name' buffer */ + + /* IN/OUT variables */ + uint32_t symnum; /* IN: Symbol to read */ + /* OUT: Next available symbol. If same as IN */ + /* then we reached the end */ + + /* OUT variables */ + GUEST_HANDLE(char) name; + uint64_t address; + char type; +}; +DEFINE_GUEST_HANDLE_STRUCT(xenpf_symdata); + struct xen_platform_op { uint32_t cmd; uint32_t interface_version; /* XENPF_INTERFACE_VERSION */ @@ -495,6 +512,7 @@ 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; }; -- cgit v1.2.3-59-g8ed1b