[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [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@xxxxxxxxxx> --- 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 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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