@@ -23,6 +23,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
- /usr/bin/pygrub symlink. This was deprecated in Xen 4.2 (2012) but left for
compatibility reasons. VMs configured with bootloader="/usr/bin/pygrub"
should be updated to just bootloader="pygrub".
+- The Xen gdbstub on x86.
## [4.18.0](https://xenbits.xenproject.org/gitweb/?p=xen.git;a=shortlog;h=RELEASE-4.18.0) - 2023-11-16
@@ -1242,13 +1242,6 @@ requirement can be relaxed. This option is particularly useful for nested
virtualization, to allow the L1 hypervisor to use EPT even if the L0 hypervisor
does not provide `VM_ENTRY_LOAD_GUEST_PAT`.
-### gdb
-> `= com1[H,L] | com2[H,L] | dbgp`
-
-> Default: ``
-
-Specify which console gdbstub should use. See **console**.
-
### gnttab
> `= List of [ max-ver:<integer>, transitive=<bool>, transfer=<bool> ]`
@@ -13,13 +13,6 @@ config DEBUG
if DEBUG || EXPERT
-config CRASH_DEBUG
- bool "Crash Debugging Support"
- depends on X86
- ---help---
- If you want to attach gdb to Xen to debug Xen if it crashes
- then say Y.
-
config GDBSX
bool "Guest debugging with gdbsx"
depends on X86
@@ -35,7 +35,6 @@ obj-y += e820.o
obj-y += emul-i8254.o
obj-y += extable.o
obj-y += flushtlb.o
-obj-$(CONFIG_CRASH_DEBUG) += gdbstub.o
obj-$(CONFIG_GDBSX) += gdbsx.o
obj-y += hypercall.o
obj-y += i387.o
deleted file mode 100644
@@ -1,91 +0,0 @@
-/*
- * x86-specific gdb stub routines
- * based on x86 cdb(xen/arch/x86/cdb.c), but Extensively modified.
- *
- * Copyright (C) 2006 Isaku Yamahata <yamahata at valinux co jp>
- * VA Linux Systems Japan. K.K.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; If not, see <http://www.gnu.org/licenses/>.
- */
-#include <asm/uaccess.h>
-#include <asm/x86-defns.h>
-
-#include <xen/gdbstub.h>
-
-u16
-gdb_arch_signal_num(struct cpu_user_regs *regs, unsigned long cookie)
-{
- return 5; /* TRAP signal. see include/gdb/signals.h */
-}
-
-/*
- * Use __copy_*_user to make us page-fault safe, but not otherwise restrict
- * our access to the full virtual address space.
- */
-unsigned int
-gdb_arch_copy_from_user(void *dest, const void *src, unsigned len)
-{
- return copy_from_unsafe(dest, src, len);
-}
-
-unsigned int
-gdb_arch_copy_to_user(void *dest, const void *src, unsigned len)
-{
- return copy_to_unsafe(dest, src, len);
-}
-
-void
-gdb_arch_print_state(struct cpu_user_regs *regs)
-{
- /* XXX */
-}
-
-void
-gdb_arch_enter(struct cpu_user_regs *regs)
-{
- /* nothing */
-}
-
-void
-gdb_arch_exit(struct cpu_user_regs *regs)
-{
- /* nothing */
-}
-
-void
-gdb_arch_resume(struct cpu_user_regs *regs,
- unsigned long addr, unsigned long type,
- struct gdb_context *ctx)
-{
- if ( addr != -1UL )
- regs->rip = addr;
-
- regs->eflags &= ~X86_EFLAGS_TF;
-
- /* Set eflags.RF to ensure we do not re-enter. */
- regs->eflags |= X86_EFLAGS_RF;
-
- /* Set the trap flag if we are single stepping. */
- if ( type == GDB_STEP )
- regs->eflags |= X86_EFLAGS_TF;
-}
-
-/*
- * Local variables:
- * mode: C
- * c-file-style: "BSD"
- * c-basic-offset: 4
- * tab-width: 4
- * End:
- */
@@ -12,5 +12,3 @@ obj-$(CONFIG_COMPAT) += domain.o
obj-$(CONFIG_COMPAT) += cpu_idle.o
obj-$(CONFIG_COMPAT) += cpufreq.o
obj-bin-$(CONFIG_KEXEC) += kexec_reloc.o
-
-obj-$(CONFIG_CRASH_DEBUG) += gdbstub.o
deleted file mode 100644
@@ -1,150 +0,0 @@
-/*
- * x86_64 -specific gdb stub routines
- *
- * Copyright (C) 2007 Dan Doucette ddoucette@teradici.com
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; If not, see <http://www.gnu.org/licenses/>.
- */
-
-#include <xen/gdbstub.h>
-
-#define GDB_REG64(r) gdb_write_to_packet_hex(r, sizeof(u64), ctx)
-#define GDB_REG32(r) gdb_write_to_packet_hex(r, sizeof(u32), ctx)
-
-void
-gdb_arch_read_reg_array(struct cpu_user_regs *regs, struct gdb_context *ctx)
-{
- GDB_REG64(regs->rax);
- GDB_REG64(regs->rbx);
- GDB_REG64(regs->rcx);
- GDB_REG64(regs->rdx);
- GDB_REG64(regs->rsi);
- GDB_REG64(regs->rdi);
- GDB_REG64(regs->rbp);
- GDB_REG64(regs->rsp);
-
- GDB_REG64(regs->r8);
- GDB_REG64(regs->r9);
- GDB_REG64(regs->r10);
- GDB_REG64(regs->r11);
- GDB_REG64(regs->r12);
- GDB_REG64(regs->r13);
- GDB_REG64(regs->r14);
- GDB_REG64(regs->r15);
-
- GDB_REG64(regs->rip);
- GDB_REG32(regs->eflags);
-
- GDB_REG32(regs->cs);
- GDB_REG32(regs->ss);
- GDB_REG32(regs->ds);
- GDB_REG32(regs->es);
- GDB_REG32(regs->fs);
- GDB_REG32(regs->gs);
-
- gdb_send_packet(ctx);
-}
-
-void
-gdb_arch_write_reg_array(struct cpu_user_regs *regs, const char* buf,
- struct gdb_context *ctx)
-{
- gdb_send_reply("", ctx);
-}
-
-void
-gdb_arch_read_reg(unsigned long regnum, struct cpu_user_regs *regs,
- struct gdb_context *ctx)
-{
- switch (regnum)
- {
- case 0: GDB_REG64(regs->rax); break;
- case 1: GDB_REG64(regs->rbx); break;
- case 2: GDB_REG64(regs->rcx); break;
- case 3: GDB_REG64(regs->rdx); break;
- case 4: GDB_REG64(regs->rsi); break;
- case 5: GDB_REG64(regs->rdi); break;
- case 6: GDB_REG64(regs->rbp); break;
- case 7: GDB_REG64(regs->rsp); break;
-
- case 8: GDB_REG64(regs->r8); break;
- case 9: GDB_REG64(regs->r9); break;
- case 10: GDB_REG64(regs->r10); break;
- case 11: GDB_REG64(regs->r11); break;
- case 12: GDB_REG64(regs->r12); break;
- case 13: GDB_REG64(regs->r13); break;
- case 14: GDB_REG64(regs->r14); break;
- case 15: GDB_REG64(regs->r15); break;
-
- case 16: GDB_REG64(regs->rip); break;
- case 17: GDB_REG32(regs->rflags); break;
- case 18: GDB_REG32(regs->cs); break;
- case 19: GDB_REG32(regs->ss); break;
- case 20: GDB_REG32(regs->ds); break;
- case 21: GDB_REG32(regs->es); break;
- case 22: GDB_REG32(regs->fs); break;
- case 23: GDB_REG32(regs->gs); break;
- default:
- GDB_REG64(0xbaadf00ddeadbeef);
- break;
- }
- gdb_send_packet(ctx);
-}
-
-void
-gdb_arch_write_reg(unsigned long regnum, unsigned long val,
- struct cpu_user_regs *regs, struct gdb_context *ctx)
-{
- switch (regnum)
- {
- case 0: regs->rax = val; break;
- case 1: regs->rbx = val; break;
- case 2: regs->rcx = val; break;
- case 3: regs->rdx = val; break;
- case 4: regs->rsi = val; break;
- case 5: regs->rdi = val; break;
- case 6: regs->rbp = val; break;
- case 7: regs->rsp = val; break;
-
- case 8: regs->r8 = val; break;
- case 9: regs->r9 = val; break;
- case 10: regs->r10 = val; break;
- case 11: regs->r11 = val; break;
- case 12: regs->r12 = val; break;
- case 13: regs->r13 = val; break;
- case 14: regs->r14 = val; break;
- case 15: regs->r15 = val; break;
-
- case 16: regs->rip = val; break;
- case 17: regs->rflags = (u32)val; break;
- case 18: regs->cs = (u16)val; break;
- case 19: regs->ss = (u16)val; break;
- case 20: regs->ds = (u16)val; break;
- case 21: regs->es = (u16)val; break;
- case 22: regs->fs = (u16)val; break;
- case 23: regs->gs = (u16)val; break;
- default:
- break;
- }
- gdb_send_reply("OK", ctx);
-}
-
-/*
- * Local variables:
- * mode: C
- * c-file-style: "BSD"
- * c-basic-offset: 4
- * tab-width: 4
- * End:
- */
@@ -12,7 +12,6 @@ obj-$(CONFIG_OVERLAY_DTB) += dt-overlay.o
obj-y += event_2l.o
obj-y += event_channel.o
obj-y += event_fifo.o
-obj-$(CONFIG_CRASH_DEBUG) += gdbstub.o
obj-$(CONFIG_GRANT_TABLE) += grant_table.o
obj-y += guestcopy.o
obj-bin-y += gunzip.init.o
deleted file mode 100644
@@ -1,748 +0,0 @@
-/*
- * Copyright (C) 2005 Jimi Xenidis <jimix@watson.ibm.com>, IBM Corporation
- * Copyright (C) 2006 Isaku Yamahata <yamahata at valinux co jp>
- * VA Linux Systems Japan. K.K.
- *
- * gdbstub arch neutral part
- * Based on x86 cdb (xen/arch/x86/cdb.c) and ppc gdbstub(xen/common/gdbstub.c)
- * But extensively modified.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; If not, see <http://www.gnu.org/licenses/>.
- */
-
-/*
- * gdbstub: implements the architecture independant parts of the
- * gdb remote protocol.
- */
-
-/* We try to avoid assuming much about what the rest of the system is
- doing. In particular, dynamic memory allocation is out of the
- question. */
-
-/* Resuming after we've stopped used to work, but more through luck
- than any actual intention. It doesn't at the moment. */
-
-#include <xen/lib.h>
-#include <xen/spinlock.h>
-#include <xen/serial.h>
-#include <xen/irq.h>
-#include <xen/watchdog.h>
-#include <xen/init.h>
-#include <xen/param.h>
-#include <xen/smp.h>
-#include <xen/console.h>
-#include <xen/errno.h>
-#include <xen/delay.h>
-#include <xen/gdbstub.h>
-
-#include <asm/byteorder.h>
-
-/* Printk isn't particularly safe just after we've trapped to the
- debugger. so avoid it. */
-#define dbg_printk(...)
-/*#define dbg_printk(...) printk(__VA_ARGS__)*/
-
-#define GDB_RETRY_MAX 10
-
-struct gdb_cpu_info
-{
- atomic_t paused;
- atomic_t ack;
-};
-
-static struct gdb_cpu_info gdb_cpu[NR_CPUS];
-static atomic_t gdb_smp_paused_count;
-
-static void gdb_smp_pause(void);
-static void gdb_smp_resume(void);
-
-static char __initdata opt_gdb[30];
-string_param("gdb", opt_gdb);
-
-static void cf_check gdbstub_console_puts(const char *str, size_t nr);
-
-/* value <-> char (de)serialzers */
-static char
-hex2char(unsigned long x)
-{
- const char array[] = "0123456789abcdef";
- return array[x & 15];
-}
-
-static unsigned int
-char2hex(unsigned char c)
-{
- if ( (c >= '0') && (c <= '9') )
- return c - '0';
- else if ( (c >= 'a') && (c <= 'f') )
- return c - 'a' + 10;
- else if ( (c >= 'A') && (c <= 'F') )
- return c - 'A' + 10;
- else
- BUG();
- return -1;
-}
-
-static unsigned char
-str2hex(const char *str)
-{
- return (char2hex(str[0]) << 4) | char2hex(str[1]);
-}
-
-static unsigned long
-str2ulong(const char *str, unsigned long bytes)
-{
- unsigned long x = 0;
- unsigned long i = 0;
-
- while ( *str && (i < (bytes * 2)) )
- {
- x <<= 4;
- x += char2hex(*str);
- ++str;
- ++i;
- }
-
- return x;
-}
-
-static unsigned long
-str_to_native_ulong(const char *str)
-{
- unsigned long x = 0, i = 0;
-
- while ( *str && (i < BYTES_PER_LONG) )
- {
-#ifdef __BIG_ENDIAN
- x <<= 8;
- x += str2hex(str);
-#elif defined(__LITTLE_ENDIAN)
- x += (unsigned long)str2hex(str) << (i*8);
-#else
-# error unknown endian
-#endif
- str += 2;
- i++;
- }
-
- return x;
-}
-
-/* gdb io wrappers */
-static signed long
-gdb_io_write(const char *buf, unsigned long len, struct gdb_context *ctx)
-{
- int i;
- for ( i = 0; i < len; i++ )
- serial_putc(ctx->serhnd, buf[i]);
- return i;
-}
-
-static int
-gdb_io_write_char(u8 data, struct gdb_context *ctx)
-{
- return gdb_io_write((char*)&data, 1, ctx);
-}
-
-static unsigned char
-gdb_io_read(struct gdb_context *ctx)
-{
- return serial_getc(ctx->serhnd);
-}
-
-/* Receive a command. Returns -1 on csum error, 0 otherwise. */
-/* Does not acknowledge. */
-static int
-attempt_receive_packet(struct gdb_context *ctx)
-{
- u8 csum;
- u8 received_csum;
- u8 ch;
-
- /* Skip over everything up to the first '$' */
- while ( (ch = gdb_io_read(ctx)) != '$' )
- continue;
-
- csum = 0;
- for ( ctx->in_bytes = 0;
- ctx->in_bytes < sizeof(ctx->in_buf);
- ctx->in_bytes++ )
- {
- ch = gdb_io_read(ctx);
- if ( ch == '#' )
- break;
- ctx->in_buf[ctx->in_bytes] = ch;
- csum += ch;
- }
-
- if ( ctx->in_bytes == sizeof(ctx->in_buf) )
- {
- dbg_printk("WARNING: GDB sent a stupidly big packet.\n");
- return -1;
- }
-
- ctx->in_buf[ctx->in_bytes] = '\0';
- received_csum = char2hex(gdb_io_read(ctx)) * 16 +
- char2hex(gdb_io_read(ctx));
-
- return (received_csum == csum) ? 0 : -1;
-}
-
-/* Receive a command, discarding up to ten packets with csum
- * errors. Acknowledges all received packets. */
-static int
-receive_command(struct gdb_context *ctx)
-{
- int r, count = 0;
-
- count = 0;
- do {
- r = attempt_receive_packet(ctx);
- gdb_io_write_char((r < 0) ? '-' : '+', ctx);
- count++;
- } while ( (r < 0) && (count < GDB_RETRY_MAX) );
-
- return r;
-}
-
-/* routines to send reply packets */
-
-static void
-gdb_start_packet(struct gdb_context *ctx)
-{
- ctx->out_buf[0] = '$';
- ctx->out_offset = 1;
- ctx->out_csum = 0;
-}
-
-static void
-gdb_write_to_packet_char(u8 data, struct gdb_context *ctx)
-{
- ctx->out_csum += data;
- ctx->out_buf[ctx->out_offset] = data;
- ctx->out_offset++;
-}
-
-void
-gdb_write_to_packet(const char *buf, int count, struct gdb_context *ctx)
-{
- int x;
- for ( x = 0; x < count; x++ )
- gdb_write_to_packet_char(buf[x], ctx);
-}
-
-void
-gdb_write_to_packet_str(const char *buf, struct gdb_context *ctx)
-{
- gdb_write_to_packet(buf, strlen(buf), ctx);
-}
-
-void
-gdb_write_to_packet_hex(unsigned long x, int int_size, struct gdb_context *ctx)
-{
- char buf[sizeof(unsigned long) * 2 + 1];
- int i, width = int_size * 2;
-
- buf[sizeof(unsigned long) * 2] = 0;
-
- switch ( int_size )
- {
- case sizeof(u8):
- case sizeof(u16):
- case sizeof(u32):
- case sizeof(u64):
- break;
- default:
- dbg_printk("WARNING: %s x: %#lx int_size: %d\n",
- __func__, x, int_size);
- break;
- }
-
-#ifdef __BIG_ENDIAN
- i = sizeof(unsigned long) * 2
- do {
- buf[--i] = hex2char(x & 15);
- x >>= 4;
- } while ( x );
-
- while ( (i + width) > (sizeof(unsigned long) * 2) )
- buf[--i] = '0';
-
- gdb_write_to_packet(&buf[i], width, ctx);
-#elif defined(__LITTLE_ENDIAN)
- i = 0;
- while ( i < width )
- {
- buf[i++] = hex2char(x>>4);
- buf[i++] = hex2char(x);
- x >>= 8;
- }
- gdb_write_to_packet(buf, width, ctx);
-#else
-# error unknown endian
-#endif
-}
-
-static int
-gdb_check_ack(struct gdb_context *ctx)
-{
- u8 c = gdb_io_read(ctx);
-
- switch ( c )
- {
- case '+':
- return 1;
- case '-':
- return 0;
- default:
- printk("Bad ack: %c\n", c);
- return 0;
- }
-}
-
-/* Return 0 if the reply was successfully received, !0 otherwise. */
-void
-gdb_send_packet(struct gdb_context *ctx)
-{
- char buf[3];
- int count;
-
- snprintf(buf, sizeof(buf), "%.02x\n", ctx->out_csum);
-
- gdb_write_to_packet_char('#', ctx);
- gdb_write_to_packet(buf, 2, ctx);
-
- count = 0;
- do {
- gdb_io_write(ctx->out_buf, ctx->out_offset, ctx);
- } while ( !gdb_check_ack(ctx) && (count++ < GDB_RETRY_MAX) );
-
- if ( count == GDB_RETRY_MAX )
- dbg_printk("WARNING: %s reached max retry %d\n",
- __func__, GDB_RETRY_MAX);
-}
-
-void
-gdb_send_reply(const char *buf, struct gdb_context *ctx)
-{
- gdb_start_packet(ctx);
- gdb_write_to_packet_str(buf, ctx);
- gdb_send_packet(ctx);
-}
-
-/* arch neutral command handlers */
-
-static void
-gdb_cmd_signum(struct gdb_context *ctx)
-{
- gdb_write_to_packet_char('S', ctx);
- gdb_write_to_packet_hex(ctx->signum, sizeof(ctx->signum), ctx);
- gdb_send_packet(ctx);
-}
-
-static void
-gdb_cmd_read_mem(unsigned long addr, unsigned long length,
- struct gdb_context *ctx)
-{
- int x, r;
- unsigned char val;
-
- dbg_printk("Memory read starting at %lx, length %lx.\n", addr,
- length);
-
- for ( x = 0; x < length; x++ )
- {
- r = gdb_arch_copy_from_user(&val, (void *)(addr + x), 1);
- if ( r != 0 )
- {
- dbg_printk("Error reading from %lx.\n", addr + x);
- break;
- }
- gdb_write_to_packet_hex(val, sizeof(val), ctx);
- }
-
- if ( x == 0 )
- gdb_write_to_packet_str("E05", ctx);
-
- dbg_printk("Read done.\n");
-
- gdb_send_packet(ctx);
-}
-
-static void
-gdb_cmd_write_mem(unsigned long addr, unsigned long length,
- const char *buf, struct gdb_context *ctx)
-{
- int x, r;
- unsigned char val;
-
- dbg_printk("Memory write starting at %lx, length %lx.\n", addr, length);
-
- for ( x = 0; x < length; x++, addr++, buf += 2 )
- {
- val = str2ulong(buf, sizeof(val));
- r = gdb_arch_copy_to_user((void*)addr, (void*)&val, 1);
- if ( r != 0 )
- {
- dbg_printk("Error writing to %lx.\n", addr);
- break;
- }
- }
-
- if (x == length)
- gdb_write_to_packet_str("OK", ctx);
- else
- gdb_write_to_packet_str("E11", ctx);
-
- dbg_printk("Write done.\n");
-
- gdb_send_packet(ctx);
-}
-
-static void
-gdbstub_attach(struct gdb_context *ctx)
-{
- if ( ctx->currently_attached )
- return;
- ctx->currently_attached = 1;
- ctx->console_steal_id = console_steal(ctx->serhnd, gdbstub_console_puts);
-}
-
-static void
-gdbstub_detach(struct gdb_context *ctx)
-{
- if ( !ctx->currently_attached )
- return;
- ctx->currently_attached = 0;
- console_giveback(ctx->console_steal_id);
-}
-
-/* command dispatcher */
-static int
-process_command(struct cpu_user_regs *regs, struct gdb_context *ctx)
-{
- const char *ptr;
- unsigned long addr, length, val;
- int resume = 0;
- unsigned long type = GDB_CONTINUE;
-
- /* XXX check ctx->in_bytes >= 2 or similar. */
-
- gdb_start_packet(ctx);
- switch ( ctx->in_buf[0] )
- {
- case '?': /* query signal number */
- gdb_cmd_signum(ctx);
- break;
- case 'H': /* thread operations */
- gdb_send_reply("OK", ctx);
- break;
- case 'g': /* Read registers */
- gdb_arch_read_reg_array(regs, ctx);
- break;
- case 'G': /* Write registers */
- gdb_arch_write_reg_array(regs, ctx->in_buf + 1, ctx);
- break;
- case 'm': /* Read memory */
- addr = simple_strtoul(ctx->in_buf + 1, &ptr, 16);
- if ( (ptr == (ctx->in_buf + 1)) || (ptr[0] != ',') )
- {
- gdb_send_reply("E03", ctx);
- return 0;
- }
- length = simple_strtoul(ptr + 1, &ptr, 16);
- if ( ptr[0] != 0 )
- {
- gdb_send_reply("E04", ctx);
- return 0;
- }
- gdb_cmd_read_mem(addr, length, ctx);
- break;
- case 'M': /* Write memory */
- addr = simple_strtoul(ctx->in_buf + 1, &ptr, 16);
- if ( (ptr == (ctx->in_buf + 1)) || (ptr[0] != ',') )
- {
- gdb_send_reply("E03", ctx);
- return 0;
- }
- length = simple_strtoul(ptr + 1, &ptr, 16);
- if ( ptr[0] != ':')
- {
- gdb_send_reply("E04", ctx);
- return 0;
- }
- gdb_cmd_write_mem(addr, length, ptr + 1, ctx);
- break;
- case 'p': /* read register */
- addr = simple_strtoul(ctx->in_buf + 1, &ptr, 16);
- if ( ptr == (ctx->in_buf + 1) )
- {
- gdb_send_reply("E03", ctx);
- return 0;
- }
- if ( ptr[0] != 0 )
- {
- gdb_send_reply("E04", ctx);
- return 0;
- }
- gdb_arch_read_reg(addr, regs, ctx);
- break;
- case 'P': /* write register */
- addr = simple_strtoul(ctx->in_buf + 1, &ptr, 16);
- if ( ptr == (ctx->in_buf + 1) )
- {
- gdb_send_reply("E03", ctx);
- return 0;
- }
- if ( ptr[0] != '=' )
- {
- gdb_send_reply("E04", ctx);
- return 0;
- }
- ptr++;
- val = str_to_native_ulong(ptr);
- gdb_arch_write_reg(addr, val, regs, ctx);
- break;
- case 'D':
- case 'k':
- gdbstub_detach(ctx);
- gdb_send_reply("OK", ctx);
- ctx->connected = 0;
- resume = 1;
- break;
- case 's': /* Single step */
- type = GDB_STEP;
- case 'c': /* Resume at current address */
- addr = ~((unsigned long)0);
-
- if ( ctx->in_buf[1] )
- addr = str2ulong(&ctx->in_buf[1], sizeof(unsigned long));
- gdbstub_attach(ctx);
- resume = 1;
- gdb_arch_resume(regs, addr, type, ctx);
- break;
- default:
- gdb_send_reply("", ctx);
- break;
- }
- return resume;
-}
-
-static struct gdb_context
-__gdb_ctx = {
- .serhnd = -1,
- .running = ATOMIC_INIT(1),
- .signum = 1
-};
-static struct gdb_context *gdb_ctx = &__gdb_ctx;
-
-static void cf_check gdbstub_console_puts(const char *str, size_t nr)
-{
- const char *p;
-
- gdb_start_packet(gdb_ctx);
- gdb_write_to_packet_char('O', gdb_ctx);
-
- for ( p = str; nr > 0; p++, nr-- )
- {
- gdb_write_to_packet_char(hex2char((*p>>4) & 0x0f), gdb_ctx );
- gdb_write_to_packet_char(hex2char((*p) & 0x0f), gdb_ctx );
- }
-
- gdb_send_packet(gdb_ctx);
-}
-
-/* trap handler: main entry point */
-int
-__trap_to_gdb(struct cpu_user_regs *regs, unsigned long cookie)
-{
- int rc = 0;
- unsigned long flags;
-
- if ( gdb_ctx->serhnd < 0 )
- {
- printk("Debugging connection not set up.\n");
- return -EBUSY;
- }
-
- /* We rely on our caller to ensure we're only on one processor
- * at a time... We should probably panic here, but given that
- * we're a debugger we should probably be a little tolerant of
- * things going wrong. */
- /* We don't want to use a spin lock here, because we're doing
- two distinct things:
-
- 1 -- we don't want to run on more than one processor at a time,
- and
- 2 -- we want to do something sensible if we re-enter ourselves.
-
- Spin locks are good for 1, but useless for 2. */
- if ( !atomic_dec_and_test(&gdb_ctx->running) )
- {
- printk("WARNING WARNING WARNING: Avoiding recursive gdb.\n");
- atomic_inc(&gdb_ctx->running);
- return -EBUSY;
- }
-
- if ( !gdb_ctx->connected )
- {
- printk("GDB connection activated.\n");
- gdb_arch_print_state(regs);
- gdb_ctx->connected = 1;
- }
-
- gdb_smp_pause();
-
- local_irq_save(flags);
-
- watchdog_disable();
- console_start_sync();
-
- gdb_arch_enter(regs);
- gdb_ctx->signum = gdb_arch_signal_num(regs, cookie);
-
- /* If gdb is already attached, tell it we've stopped again. */
- if ( gdb_ctx->currently_attached )
- {
- gdb_start_packet(gdb_ctx);
- gdb_cmd_signum(gdb_ctx);
- }
-
- do {
- if ( receive_command(gdb_ctx) < 0 )
- {
- dbg_printk("Error in GDB session...\n");
- rc = -EIO;
- break;
- }
- } while ( process_command(regs, gdb_ctx) == 0 );
-
- gdb_smp_resume();
-
- gdb_arch_exit(regs);
- console_end_sync();
- watchdog_enable();
- atomic_inc(&gdb_ctx->running);
-
- local_irq_restore(flags);
-
- return rc;
-}
-
-static int __init cf_check initialise_gdb(void)
-{
- if ( *opt_gdb == '\0' )
- return 0;
-
- gdb_ctx->serhnd = serial_parse_handle(opt_gdb);
- if ( gdb_ctx->serhnd == -1 )
- {
- printk("Bad gdb= option '%s'\n", opt_gdb);
- return 0;
- }
-
- serial_start_sync(gdb_ctx->serhnd);
-
- printk("GDB stub initialised.\n");
-
- return 0;
-}
-presmp_initcall(initialise_gdb);
-
-static void cf_check gdb_pause_this_cpu(void *unused)
-{
- unsigned long flags;
-
- local_irq_save(flags);
-
- atomic_set(&gdb_cpu[smp_processor_id()].ack, 1);
- atomic_inc(&gdb_smp_paused_count);
-
- while ( atomic_read(&gdb_cpu[smp_processor_id()].paused) )
- mdelay(1);
-
- atomic_dec(&gdb_smp_paused_count);
- atomic_set(&gdb_cpu[smp_processor_id()].ack, 0);
-
- /* Restore interrupts */
- local_irq_restore(flags);
-}
-
-static void gdb_smp_pause(void)
-{
- int timeout = 100;
- int cpu;
-
- for_each_online_cpu(cpu)
- {
- atomic_set(&gdb_cpu[cpu].ack, 0);
- atomic_set(&gdb_cpu[cpu].paused, 1);
- }
-
- atomic_set(&gdb_smp_paused_count, 0);
-
- smp_call_function(gdb_pause_this_cpu, NULL, /* dont wait! */0);
-
- /* Wait 100ms for all other CPUs to enter pause loop */
- while ( (atomic_read(&gdb_smp_paused_count) < (num_online_cpus() - 1))
- && (timeout-- > 0) )
- mdelay(1);
-
- if ( atomic_read(&gdb_smp_paused_count) < (num_online_cpus() - 1) )
- {
- printk("GDB: Not all CPUs have paused, missing CPUs ");
- for_each_online_cpu(cpu)
- {
- if ( (cpu != smp_processor_id()) &&
- !atomic_read(&gdb_cpu[cpu].ack) )
- printk("%d ", cpu);
- }
- printk("\n");
- }
-}
-
-static void gdb_smp_resume(void)
-{
- int cpu;
- int timeout = 100;
-
- for_each_online_cpu(cpu)
- atomic_set(&gdb_cpu[cpu].paused, 0);
-
- /* Make sure all CPUs resume */
- while ( (atomic_read(&gdb_smp_paused_count) > 0)
- && (timeout-- > 0) )
- mdelay(1);
-
- if ( atomic_read(&gdb_smp_paused_count) > 0 )
- {
- printk("GDB: Not all CPUs have resumed execution, missing CPUs ");
- for_each_online_cpu(cpu)
- {
- if ( (cpu != smp_processor_id()) &&
- atomic_read(&gdb_cpu[cpu].ack) )
- printk("%d ", cpu);
- }
- printk("\n");
- }
-}
-
-/*
- * Local variables:
- * mode: C
- * c-file-style: "BSD"
- * c-basic-offset: 4
- * tab-width: 4
- * End:
- */
deleted file mode 100644
@@ -1,103 +0,0 @@
-/*
- * Copyright (C) 2005 Hollis Blanchard <hollisb@us.ibm.com>, IBM Corporation
- * Copyright (C) 2006 Isaku Yamahata <yamahata at valinux co jp>
- * VA Linux Systems Japan. K.K.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; If not, see <http://www.gnu.org/licenses/>.
- */
-
-#ifndef __XEN_GDBSTUB_H__
-#define __XEN_GDBSTUB_H__
-
-#include <xen/page-size.h>
-#include <asm/atomic.h>
-
-#ifdef CONFIG_CRASH_DEBUG
-
-struct cpu_user_regs;
-
-struct gdb_context {
- int serhnd; /* handle on our serial line */
- int console_steal_id; /* handle on stolen console */
- bool currently_attached;
- atomic_t running;
- unsigned long connected;
- u8 signum;
-
- char in_buf[PAGE_SIZE];
- unsigned long in_bytes;
-
- char out_buf[PAGE_SIZE];
- unsigned long out_offset;
- u8 out_csum;
-};
-
-/* interface to arch specific routines */
-void gdb_write_to_packet(
- const char *buf, int count, struct gdb_context *ctx);
-void gdb_write_to_packet_hex(
- unsigned long x, int int_size, struct gdb_context *ctx);
- /* ... writes in target native byte order as required by gdb spec. */
-void gdb_send_packet(struct gdb_context *ctx);
-void gdb_send_reply(const char *buf, struct gdb_context *ctx);
-
-/* gdb stub trap handler: entry point */
-int __trap_to_gdb(struct cpu_user_regs *regs, unsigned long cookie);
-
-/* arch specific routines */
-u16 gdb_arch_signal_num(
- struct cpu_user_regs *regs, unsigned long cookie);
-void gdb_arch_read_reg_array(
- struct cpu_user_regs *regs, struct gdb_context *ctx);
-void gdb_arch_write_reg_array(
- struct cpu_user_regs *regs, const char* buf, struct gdb_context *ctx);
-void gdb_arch_read_reg(
- unsigned long regnum, struct cpu_user_regs *regs, struct gdb_context *ctx);
-void gdb_arch_write_reg(
- unsigned long regnum, unsigned long val, struct cpu_user_regs *regs,
- struct gdb_context *ctx);
-unsigned int gdb_arch_copy_from_user(
- void *dest, const void *src, unsigned len);
-unsigned int gdb_arch_copy_to_user(
- void *dest, const void *src, unsigned len);
-void gdb_arch_resume(
- struct cpu_user_regs *regs, unsigned long addr,
- unsigned long type, struct gdb_context *ctx);
-void gdb_arch_print_state(struct cpu_user_regs *regs);
-void gdb_arch_enter(struct cpu_user_regs *regs);
-void gdb_arch_exit(struct cpu_user_regs *regs);
-
-#define GDB_CONTINUE 0
-#define GDB_STEP 1
-
-#define SIGILL 4
-#define SIGTRAP 5
-#define SIGBUS 7
-#define SIGFPE 8
-#define SIGSEGV 11
-#define SIGALRM 14
-#define SIGTERM 15
-
-#endif
-
-#endif /* __XEN_GDBSTUB_H__ */
-
-/*
- * Local variables:
- * mode: C
- * c-file-style: "BSD"
- * c-basic-offset: 4
- * tab-width: 4
- * End:
- */
In 13y of working on Xen, I've never seen seen it used. The implementation was introduced (commit b69f92f3012e, Jul 28 2004) with known issues such as: /* Resuming after we've stopped used to work, but more through luck than any actual intention. It doesn't at the moment. */ which appear to have gone unfixed for the 20 years since. Nowadays there are more robust ways of inspecting crashed state, such as a kexec crash kernel, or running Xen in a VM. This will allow us to clean up some hooks around the codebase which are proving awkward for other tasks. Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> --- CC: Jan Beulich <JBeulich@suse.com> CC: Roger Pau Monné <roger.pau@citrix.com> CC: Wei Liu <wl@xen.org> CC: Oleksii Kurochko <oleksii.kurochko@gmail.com> Bloat-o-meter really likes this change. add/remove: 1/31 grow/shrink: 2/15 up/down: 113/-17033 (-16920) Function old new delta hwdom_shutdown 101 176 +75 do_int3.cold - 27 +27 do_bug_frame 566 577 +11 panic.cold 98 97 -1 gdb_arch_print_state 1 - -1 gdb_arch_exit 1 - -1 gdb_arch_enter 1 - -1 do_page_fault.cold 55 53 -2 gdb_smp_paused_count 4 - -4 __setup_str_opt_gdb 4 - -4 gdb_arch_copy_to_user 5 - -5 gdb_arch_copy_from_user 5 - -5 gdb_arch_signal_num 6 - -6 xen_config_data 1280 1273 -7 __initcall_initialise_gdb 8 - -8 do_debugger_trap_fatal 15 5 -10 do_debug_key 48 35 -13 gdb_arch_write_reg_array 15 - -15 gdb_send_packet.cold 16 - -16 do_debug 457 441 -16 do_trap 213 194 -19 do_int3 251 230 -21 do_invalid_op 331 307 -24 __setup_opt_gdb 24 - -24 opt_gdb 30 - -30 do_unhandled_trap 38 7 -31 cpumask_first.constprop 138 104 -34 cpumask_next.constprop 174 129 -45 gdb_arch_resume 52 - -52 char2hex 58 - -58 do_page_fault 1820 1752 -68 gdb_write_to_packet 69 - -69 do_general_protection 542 471 -71 initialise_gdb 81 - -81 gdb_write_to_packet_str 86 - -86 do_bug_frame.cold 131 39 -92 gdb_send_reply 110 - -110 hwdom_shutdown.cold 140 - -140 gdb_pause_this_cpu 159 - -159 gdb_write_to_packet_hex 200 - -200 gdb_send_packet 216 - -216 gdbstub_console_puts 220 - -220 __trap_to_gdb.cold 313 - -313 gdb_arch_read_reg_array 451 - -451 gdb_arch_write_reg 585 - -585 gdb_arch_read_reg 883 - -883 gdb_cpu 2048 - -2048 __trap_to_gdb 2540 - -2540 __gdb_ctx 8248 - -8248 Total: Before=4081568, After=4064648, chg -0.41% --- CHANGELOG.md | 1 + docs/misc/xen-command-line.pandoc | 7 - xen/Kconfig.debug | 7 - xen/arch/x86/Makefile | 1 - xen/arch/x86/gdbstub.c | 91 ---- xen/arch/x86/x86_64/Makefile | 2 - xen/arch/x86/x86_64/gdbstub.c | 150 ------ xen/common/Makefile | 1 - xen/common/gdbstub.c | 748 ------------------------------ xen/include/xen/gdbstub.h | 103 ---- 10 files changed, 1 insertion(+), 1110 deletions(-) delete mode 100644 xen/arch/x86/gdbstub.c delete mode 100644 xen/arch/x86/x86_64/gdbstub.c delete mode 100644 xen/common/gdbstub.c delete mode 100644 xen/include/xen/gdbstub.h base-commit: c378ff8983cd69786c35117e49640f027e581bca