|
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Minios-devel] [UNIKRAFT PATCH RFC 2/5] plat/common: Introduce read_allsymbol
After kallsyms translates all symbol name into assembly code file,
comipler and linker will link this assembly file to unikraft image.
read_allsymbol will read all symbol names from the obj file.
Signed-off-by: Jia He <justin.he@xxxxxxx>
---
plat/common/include/read_allsymbol.h | 70 ++++++
plat/common/read_allsymbol.c | 332 +++++++++++++++++++++++++++
plat/kvm/Makefile.uk | 8 +
3 files changed, 410 insertions(+)
create mode 100644 plat/common/include/read_allsymbol.h
create mode 100644 plat/common/read_allsymbol.c
diff --git a/plat/common/include/read_allsymbol.h
b/plat/common/include/read_allsymbol.h
new file mode 100644
index 0000000..6b89417
--- /dev/null
+++ b/plat/common/include/read_allsymbol.h
@@ -0,0 +1,70 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Authors: Jia He <justin.he@xxxxxxx>
+ *
+ * Copyright (c) 2019, Arm Ltd. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holder nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * THIS HEADER MAY NOT BE EXTRACTED OR MODIFIED IN ANY WAY.
+ */
+#ifndef _LINUX_UKALLSYMS_H
+#define _LINUX_UKALLSYMS_H
+
+#include <errno.h>
+#include <sections.h>
+
+#define KSYM_NAME_LEN 128
+#define KSYM_SYMBOL_LEN (sizeof("%s+%#lx/%#lx [%s]") + (KSYM_NAME_LEN - 1) + \
+ 2*(64*3/10) + 1)
+
+static inline int is_ksym_addr(unsigned long addr)
+{
+ if (addr >= (unsigned long)__TEXT && addr <= (unsigned long)__END)
+ return 1;
+ return 0;
+}
+
+#ifdef CONFIG_DEBUG_BACK_TRACE
+
+/* Look up a kernel symbol and return it in a text buffer. */
+extern int sprint_symbol(char *buffer, unsigned long address);
+extern void uk_dump_backtrace(void);
+
+#else /* !CONFIG_DEBUG_BACK_TRACE */
+static inline int sprint_symbol(char *buffer, unsigned long addr)
+{
+ *buffer = '\0';
+ return 0;
+}
+
+void uk_dump_backtrace(void)
+{
+}
+#endif /*CONFIG_DEBUG_BACK_TRACE */
+
+#endif /*_LINUX_UKALLSYMS_H*/
+
diff --git a/plat/common/read_allsymbol.c b/plat/common/read_allsymbol.c
new file mode 100644
index 0000000..6afc785
--- /dev/null
+++ b/plat/common/read_allsymbol.c
@@ -0,0 +1,332 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+/*
+ * read_allsyms.c: printing of symbolic oopses and stack traces.
+ * Authors: Jia He <justin.he@xxxxxxx>
+ *
+ * Copyright (c) 2019, Arm Ltd. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holder nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * THIS HEADER MAY NOT BE EXTRACTED OR MODIFIED IN ANY WAY.
+ */
+/*
+ * This is simplified and rewritten from kernel/kallsyms.c
+ * CommitID: 2a1a3fa0
+ */
+#include <inttypes.h>
+#include <stddef.h>
+#include <string.h>
+#include <stdio.h>
+
+#include <uk/essentials.h>
+#include <uk/print.h>
+#include <uk/assert.h>
+
+#include "read_allsymbol.h"
+
+/*
+ * These will be re-linked against their real values
+ * during the second link stage.
+ */
+extern const unsigned long ukallsyms_addresses[] __weak;
+extern const __u8 ukallsyms_names[] __weak;
+
+extern const unsigned long ukallsyms_num_syms __weak;
+
+extern const __u8 ukallsyms_token_table[] __weak;
+extern const __u16 ukallsyms_token_index[] __weak;
+extern const unsigned long ukallsyms_markers[] __weak;
+
+struct stackframe {
+ unsigned long fp;
+ unsigned long pc;
+};
+
+/*
+ * Expand a compressed symbol data into the resulting uncompressed string,
+ * if uncompressed string is too long (>= maxlen), it will be truncated,
+ * given the offset to where the symbol is in the compressed stream.
+ * e.g.
+ * 0x03, 0xbe, 0xbc, 0x71
+ * len is 0x03, then ukallsyms_token_index[0xbe] is the index of this token
+ * in ukallsyms_token_table[]
+ */
+static unsigned int expand_symbol(unsigned int off, char *result, size_t
maxlen)
+{
+ int len, skipped = 0;
+ const __u8 *token, *data;
+
+ /* Get the compressed symbol length from the first symbol byte. */
+ data = &ukallsyms_names[off];
+ len = *data;
+ data++;
+
+ /*
+ * Update the offset to return the offset for the next symbol on
+ * the compressed stream.
+ */
+ off += len + 1;
+
+ /*
+ * For every byte on the compressed symbol data, copy the table
+ * entry for that byte.
+ */
+ while (len) {
+ token = &ukallsyms_token_table[ukallsyms_token_index[*data]];
+ data++;
+ len--;
+
+ /* skip the first char which is the length */
+ while (*token) {
+ if (skipped) {
+ if (maxlen <= 1)
+ goto tail;
+ *result = *token;
+ result++;
+ maxlen--;
+ } else
+ skipped = 1;
+ token++;
+ }
+ }
+
+tail:
+ /* Truncate if it is longer than maxlen */
+ if (maxlen)
+ *result = '\0';
+
+ /* Return to offset to the next symbol. */
+ return off;
+}
+
+/*
+ * Find the offset on the compressed stream given and index in the
+ * ukallsyms array.
+ */
+static unsigned int get_symbol_offset(unsigned long pos)
+{
+ const __u8 *name;
+ unsigned int i;
+
+ /*
+ * Use the closest marker we have. We have markers every 256 positions,
+ * so that should be close enough.
+ */
+ name = &ukallsyms_names[ukallsyms_markers[pos >> 8]];
+
+ /*
+ * Sequentially scan all the symbols up to the point we're searching
+ * for. Every symbol is stored in a [<len>][<len> bytes of data] format,
+ * so we just need to add the len to the current pointer for every
+ * symbol we wish to skip.
+ */
+ for (i = 0; i < (unsigned int)(pos & 0xFF); i++)
+ name = name + (*name) + 1;
+
+ return name - ukallsyms_names;
+}
+
+static unsigned long get_symbol_pos(unsigned long addr,
+ unsigned long *symbol_size,
+ unsigned long *offset)
+{
+ unsigned long symbol_start = 0, symbol_end = 0;
+ unsigned long i, low, high, mid = 0;
+
+ /* Do a binary search on the sorted ukallsyms_addresses array. */
+ low = 0;
+ high = ukallsyms_num_syms;
+
+ while (high - low > 1) {
+ mid = low + (high - low) / 2;
+ if (ukallsyms_addresses[mid] <= addr)
+ low = mid;
+ else
+ high = mid;
+ }
+
+ /*
+ * Search for the first aliased symbol. Aliased
+ * symbols are symbols with the same address.
+ */
+ while (low && ukallsyms_addresses[low-1] == ukallsyms_addresses[low])
+ --low;
+
+ symbol_start = ukallsyms_addresses[low];
+
+ /* Search for next non-aliased symbol. */
+ for (i = low + 1; i < ukallsyms_num_syms; i++) {
+ if (ukallsyms_addresses[i] > symbol_start) {
+ symbol_end = ukallsyms_addresses[i];
+ break;
+ }
+ }
+
+ /* If we found no next symbol, we use the end of the section. */
+ if (!symbol_end) {
+ symbol_end = (unsigned long)__END;
+ }
+
+ if (symbol_size)
+ *symbol_size = symbol_end - symbol_start;
+ if (offset)
+ *offset = addr - symbol_start;
+
+ return low;
+}
+
+/*
+ * Lookup an address
+ * - We guarantee that the returned name is valid until we reschedule even if.
+ * It resides in a module.
+ */
+static const char *allsyms_lookup(unsigned long addr,
+ unsigned long *symbol_size,
+ unsigned long *offset,
+ char *namebuf)
+{
+ namebuf[KSYM_NAME_LEN - 1] = 0;
+ namebuf[0] = 0;
+
+ if (is_ksym_addr(addr)) {
+ unsigned long pos;
+
+ pos = get_symbol_pos(addr, symbol_size, offset);
+ /* Grab name */
+ expand_symbol(get_symbol_offset(pos), namebuf, KSYM_NAME_LEN);
+
+ return namebuf;
+ }
+
+ return 0;
+}
+
+
+/**
+ * sprint_symbol - Look up a kernel symbol and return it in a text buffer
+ * @buffer: buffer to be stored
+ * @address: address to lookup
+ *
+ * This function looks up a kernel symbol with @address and stores its name,
+ * offset, size and module name to @buffer if possible. If no symbol was found,
+ * just saves its @address as is.
+ *
+ * This function returns the number of bytes stored in @buffer.
+ */
+int sprint_symbol(char *buffer, unsigned long address)
+{
+ const char *name;
+ unsigned long offset, size;
+ int len;
+
+ name = allsyms_lookup(address, &size, &offset, buffer);
+ if (!name)
+ return sprintf(buffer, "0x%lx", address);
+
+ if (name != buffer)
+ strcpy(buffer, name);
+ len = strlen(buffer);
+
+ len += sprintf(buffer + len, "+%#lx/%#lx", offset, size);
+
+ return len;
+}
+
+/*
+ * AArch64 PCS assigns the frame pointer to x29.
+ *
+ * A simple function prologue looks like this:
+ * sub sp, sp, #0x10
+ * stp x29, x30, [sp]
+ * mov x29, sp
+ *
+ * A simple function epilogue looks like this:
+ * mov sp, x29
+ * ldp x29, x30, [sp]
+ * add sp, sp, #0x10
+ */
+static int unwind_frame(struct stackframe *frame)
+{
+ unsigned long fp = frame->fp;
+
+ if (fp & 0xf)
+ return -1;
+
+ frame->fp = (*(unsigned long *)(fp));
+ frame->pc = (*(unsigned long *)(fp + 8));
+
+ /*
+ * Frames created upon entry from EL0 have NULL FP and PC values, so
+ * don't bother reporting these. Frames created by __noreturn functions
+ * might have a valid FP even if PC is bogus, so only terminate where
+ * both are NULL.
+ */
+ if (!frame->fp && !frame->pc)
+ return -1;
+
+ if (!is_ksym_addr(frame->pc))
+ return -1;
+ return 0;
+}
+
+static void dump_backtrace_entry(unsigned long where)
+{
+ char buffer[KSYM_NAME_LEN];
+
+ sprint_symbol(buffer, where);
+ printf("\t[0x%lx] %s\n", where, buffer);
+}
+
+int ukallsyms_on_each_symbol(int (*fn)(void *, const char *, unsigned long),
+ void *data)
+{
+ char namebuf[KSYM_NAME_LEN];
+ unsigned long i;
+ unsigned int off;
+ int ret;
+
+ for (i = 0, off = 0; i < ukallsyms_num_syms; i++) {
+ off = expand_symbol(off, namebuf, ARRAY_SIZE(namebuf));
+ ret = fn(data, namebuf, ukallsyms_addresses[i]);
+ if (ret != 0)
+ return ret;
+ }
+ return 0;
+}
+
+void uk_dump_backtrace(void)
+{
+ struct stackframe frame;
+
+ frame.fp = (unsigned long)__builtin_frame_address(0);
+ frame.pc = (unsigned long)uk_dump_backtrace;
+
+ printf("Call trace:\n");
+ do {
+ dump_backtrace_entry(frame.pc);
+ } while (!unwind_frame(&frame));
+}
+
diff --git a/plat/kvm/Makefile.uk b/plat/kvm/Makefile.uk
index 5d87352..4cdb759 100644
--- a/plat/kvm/Makefile.uk
+++ b/plat/kvm/Makefile.uk
@@ -100,6 +100,14 @@ LIBKVMPLAT_SRCS-y +=
$(UK_PLAT_COMMON_BASE)/lcpu.c|common
LIBKVMPLAT_SRCS-y += $(UK_PLAT_COMMON_BASE)/memory.c|common
LIBKVMPLAT_SRCS-y += $(UK_PLAT_KVM_DEF_LDS)
+##
+## Support dumping backtrace
+##
+ifeq ($(CONFIG_DEBUG_BACK_TRACE),y)
+LIBKVMPLAT_SRCS-y += $(UK_PLAT_COMMON_BASE)/read_allsymbol.c|common
+endif
+
+
##
## PCI library definitions
##
--
2.17.1
_______________________________________________
Minios-devel mailing list
Minios-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/minios-devel
|
 |
Lists.xenproject.org is hosted with RackSpace, monitoring our |