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kvm tools: Lookup symbol based on RIP for 'kill -3'

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To make debugging easier, look up symbol from guest kernel image based on RIP
when user does 'kill -3' to the hypervisor.

Example output looks as follows:

  Code:
  -----
  rip: [<ffffffff812cb3a0>] delay_loop+30 (/home/penberg/linux/arch/x86/lib/delay.c:32)

Cc: Asias He <asias.hejun@gmail.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Prasad Joshi <prasadjoshi124@gmail.com>
Cc: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
This commit is contained in:
Pekka Enberg
2011-05-11 19:14:39 +03:00
committed by Will Deacon
parent 3780b3d5e7
commit b0b42ba014
6 changed files with 161 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files
Makefile
+2
View File
@@ -24,6 +24,7 @@ OBJS += main.o
OBJS += mmio.o
OBJS += pci.o
OBJS += rtc.o
OBJS += symbol.o
OBJS += term.o
OBJS += util.o
OBJS += virtio/blk.o
@@ -50,6 +51,7 @@ OBJS += bios/bios.o
LIBS += -lrt
LIBS += -lpthread
LIBS += -lbfd
# Additional ARCH settings for x86
ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/i386/ -e s/sun4u/sparc64/ \
include/kvm/kvm.h
+2
View File
@@ -28,6 +28,8 @@ struct kvm {
u16 boot_sp;
struct interrupt_table interrupt_table;
const char *vmlinux;
};
struct kvm *kvm__init(const char *kvm_dev, unsigned long ram_size);
include/kvm/symbol.h
+12
View File
@@ -0,0 +1,12 @@
#ifndef KVM__SYMBOL_H
#define KVM__SYMBOL_H
#include <stddef.h>
struct kvm;
void symbol__init(const char *vmlinux);
char *symbol__lookup(struct kvm *kvm, unsigned long addr, char *sym, size_t size);
#endif /* KVM__SYMBOL_H */
kvm-cpu.c
+9
View File
@@ -1,5 +1,6 @@
#include "kvm/kvm-cpu.h"
#include "kvm/symbol.h"
#include "kvm/util.h"
#include "kvm/kvm.h"
@@ -9,6 +10,7 @@
#include <sys/mman.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <stdio.h>
@@ -282,11 +284,14 @@ void kvm_cpu__show_registers(struct kvm_cpu *vcpu)
printf("\n");
}
#define MAX_SYM_LEN 128
void kvm_cpu__show_code(struct kvm_cpu *vcpu)
{
unsigned int code_bytes = 64;
unsigned int code_prologue = code_bytes * 43 / 64;
unsigned int code_len = code_bytes;
char sym[MAX_SYM_LEN];
unsigned char c;
unsigned int i;
u8 *ip;
@@ -302,6 +307,10 @@ void kvm_cpu__show_code(struct kvm_cpu *vcpu)
printf("\n Code:\n");
printf( " -----\n");
symbol__lookup(vcpu->kvm, vcpu->regs.rip, sym, MAX_SYM_LEN);
printf(" rip: [<%016lx>] %s\n\n", (unsigned long) vcpu->regs.rip, sym);
for (i = 0; i < code_len; i++, ip++) {
if (!host_ptr_in_ram(vcpu->kvm, ip))
break;
kvm-run.c
+38 -5
View File
@@ -26,6 +26,7 @@
#include <kvm/ioport.h>
#include <kvm/threadpool.h>
#include <kvm/barrier.h>
#include <kvm/symbol.h>
/* header files for gitish interface */
#include <kvm/kvm-run.h>
@@ -52,6 +53,7 @@ static u64 ram_size;
static u8 image_count;
static const char *kernel_cmdline;
static const char *kernel_filename;
static const char *vmlinux_filename;
static const char *initrd_filename;
static const char *image_filename[MAX_DISK_IMAGES];
static const char *console;
@@ -214,17 +216,25 @@ panic_kvm:
}
static char kernel[PATH_MAX];
const char *host_kernels[] = {
static const char *host_kernels[] = {
"/boot/vmlinuz",
"/boot/bzImage",
NULL
};
const char *default_kernels[] = {
static const char *default_kernels[] = {
"./bzImage",
"../../arch/x86/boot/bzImage",
NULL
};
static const char *default_vmlinux[] = {
"../../../vmlinux",
"../../vmlinux",
NULL
};
static void kernel_usage_with_options(void)
{
const char **k;
@@ -317,6 +327,23 @@ static const char *find_kernel(void)
return NULL;
}
static const char *find_vmlinux(void)
{
const char **vmlinux;
vmlinux = &default_vmlinux[0];
while (*vmlinux) {
struct stat st;
if (stat(*vmlinux, &st) < 0 || !S_ISREG(st.st_mode)) {
vmlinux++;
continue;
}
return *vmlinux;
}
return NULL;
}
static int root_device(char *dev, long *part)
{
struct stat st;
@@ -359,13 +386,13 @@ static char *host_image(char *cmd_line, size_t size)
int kvm_cmd_run(int argc, const char **argv, const char *prefix)
{
struct virtio_net_parameters net_params;
static char real_cmdline[2048];
unsigned int nr_online_cpus;
int max_cpus;
int exit_code = 0;
int i;
struct virtio_net_parameters net_params;
int max_cpus;
char *hi;
int i;
signal(SIGALRM, handle_sigalrm);
signal(SIGQUIT, handle_sigquit);
@@ -399,6 +426,8 @@ int kvm_cmd_run(int argc, const char **argv, const char *prefix)
return EINVAL;
}
vmlinux_filename = find_vmlinux();
if (nrcpus < 1 || nrcpus > KVM_NR_CPUS)
die("Number of CPUs %d is out of [1;%d] range", nrcpus, KVM_NR_CPUS);
@@ -433,6 +462,8 @@ int kvm_cmd_run(int argc, const char **argv, const char *prefix)
if (!script)
script = DEFAULT_SCRIPT;
symbol__init(vmlinux_filename);
term_init();
kvm = kvm__init(kvm_dev, ram_size);
@@ -482,6 +513,8 @@ int kvm_cmd_run(int argc, const char **argv, const char *prefix)
real_cmdline))
die("unable to load kernel %s", kernel_filename);
kvm->vmlinux = vmlinux_filename;
ioport__setup_legacy();
rtc__init();
symbol.c
+98
View File
@@ -0,0 +1,98 @@
#include "kvm/symbol.h"
#include "kvm/kvm.h"
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <bfd.h>
static bfd *abfd;
void symbol__init(const char *vmlinux)
{
if (!vmlinux)
return;
bfd_init();
abfd = bfd_openr(vmlinux, NULL);
}
static asymbol *lookup(asymbol **symbols, int nr_symbols, const char *symbol_name)
{
int i;
for (i = 0; i < nr_symbols; i++) {
asymbol *symbol = symbols[i];
if (!strcmp(bfd_asymbol_name(symbol), symbol_name))
return symbol;
}
return NULL;
}
char *symbol__lookup(struct kvm *kvm, unsigned long addr, char *sym, size_t size)
{
const char *filename;
bfd_vma sym_offset;
bfd_vma sym_start;
asection *section;
unsigned int line;
const char *func;
long symtab_size;
asymbol *symbol;
asymbol **syms;
int nr_syms;
char *s;
if (!abfd)
goto not_found;
if (!bfd_check_format(abfd, bfd_object))
goto not_found;
symtab_size = bfd_get_symtab_upper_bound(abfd);
if (!symtab_size)
goto not_found;
syms = malloc(symtab_size);
if (!syms)
goto not_found;
nr_syms = bfd_canonicalize_symtab(abfd, syms);
section = bfd_get_section_by_name(abfd, ".debug_aranges");
if (!section)
goto not_found;
if (!bfd_find_nearest_line(abfd, section, NULL, addr, &filename, &func, &line))
goto not_found;
if (!func)
goto not_found;
symbol = lookup(syms, nr_syms, func);
if (!symbol)
goto not_found;
sym_start = bfd_asymbol_value(symbol);
sym_offset = addr - sym_start;
snprintf(sym, size, "%s+%llx (%s:%i)", func, (long long) sym_offset, filename, line);
sym[size - 1] = '\0';
free(syms);
return sym;
not_found:
s = strncpy(sym, "<unknown>", size);
sym[size - 1] = '\0';
return s;
}