mirror/freebsd
1
0
Fork 0
mirror of https://git.FreeBSD.org/src.git synced 2025-01-15 15:06:42 +00:00
Code Issues Releases Activity

Reliably enable debug exceptions on all CPUs.

Browse Source 
Previously, debug exceptions were only enabled on the boot CPU if
DDB was enabled in the dbg_monitor_init() function.  APs also called
this function, but since mp_machdep.c doesn't include opt_ddb.h, the
APs ended up calling an empty stub defined in <machine/debug_monitor.h>
instead of the real function.  Also, if DDB was not enabled in the kernel,
the boot CPU would not enable debug exceptions.

Fix this by adding a new dbg_init() function that always clears the OS
lock to enable debug exceptions which the boot CPU and the APs call.
This function also calls dbg_monitor_init() to enable hardware breakpoints
from DDB on all CPUs if DDB is enabled.  Eventually base support for
hardware breakpoints/watchpoints will need to move out of the DDB-only
debug_monitor.c for use by userland debuggers.

Reviewed by:	andrew
Differential Revision:	https://reviews.freebsd.org/D12001
This commit is contained in:
John Baldwin 2017-08-12 18:42:54 +00:00
parent c9ee3caf19
commit 992029ba10
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=322437
4 changed files with 17 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
sys/arm64/arm64/debug_monitor.c
View File

@ -453,15 +453,12 @@ dbg_monitor_init(void)
{
u_int i;
/* Clear OS lock */
WRITE_SPECIALREG(OSLAR_EL1, 0);
/* Find out many breakpoints and watchpoints we can use */
dbg_watchpoint_num = ((READ_SPECIALREG(ID_AA64DFR0_EL1) >> 20) & 0xf) + 1;
dbg_breakpoint_num = ((READ_SPECIALREG(ID_AA64DFR0_EL1) >> 12) & 0xf) + 1;
if (bootverbose && PCPU_GET(cpuid) == 0) {
db_printf("%d watchpoints and %d breakpoints supported\n",
printf("%d watchpoints and %d breakpoints supported\n",
dbg_watchpoint_num, dbg_breakpoint_num);
}

15
sys/arm64/arm64/machdep.c
View File

@ -1051,13 +1051,26 @@ initarm(struct arm64_bootparams *abp)
mutex_init();
init_param2(physmem);
dbg_monitor_init();
dbg_init();
kdb_init();
pan_enable();
early_boot = 0;
}
void
dbg_init(void)
{
/* Clear OS lock */
WRITE_SPECIALREG(OSLAR_EL1, 0);
/* This permits DDB to use debug registers for watchpoints. */
dbg_monitor_init();
/* TODO: Eventually will need to initialize debug registers here. */
}
#ifdef DDB
#include <ddb/ddb.h>

3
sys/arm64/arm64/mp_machdep.c
View File

@ -52,7 +52,6 @@ __FBSDID("$FreeBSD$");
#include <vm/vm_extern.h>
#include <vm/vm_kern.h>
#include <machine/debug_monitor.h>
#include <machine/machdep.h>
#include <machine/intr.h>
#include <machine/smp.h>
@ -272,7 +271,7 @@ init_secondary(uint64_t cpu)
vfp_init();
#endif
dbg_monitor_init();
dbg_init();
pan_enable();
/* Enable interrupts */

1
sys/arm64/include/machdep.h
View File

@ -48,6 +48,7 @@ extern enum arm64_bus arm64_bus_method;
extern vm_paddr_t physmap[];
extern u_int physmap_idx;
void dbg_init(void);
void initarm(struct arm64_bootparams *);
extern void (*pagezero)(void *);