[patch 15/15] Add hardware breakpoint support for i386

From: Tom Rini
Date: Fri Jul 29 2005 - 18:33:47 EST




This adds hardware breakpoint support for i386. This is not as well tested as
software breakpoints, but in some minimal testing appears to be functional.

---

linux-2.6.13-rc3-trini/arch/i386/kernel/kgdb.c | 49 +++++++++++++++++++++++++
1 files changed, 49 insertions(+)

diff -puN arch/i386/kernel/kgdb.c~i386 arch/i386/kernel/kgdb.c
--- linux-2.6.13-rc3/arch/i386/kernel/kgdb.c~i386 2005-07-29 12:02:15.000000000 -0700
+++ linux-2.6.13-rc3-trini/arch/i386/kernel/kgdb.c 2005-07-29 12:02:15.000000000 -0700
@@ -184,6 +184,54 @@ void kgdb_correct_hw_break(void)
asm volatile ("movl %0, %%db7\n"::"r" (dr7));
}

+int kgdb_remove_hw_break(unsigned long addr)
+{
+ int i, idx = -1;
+ for (i = 0; i < 4; i++) {
+ if (breakinfo[i].addr == addr && breakinfo[i].enabled) {
+ idx = i;
+ break;
+ }
+ }
+ if (idx == -1)
+ return -1;
+
+ breakinfo[idx].enabled = 0;
+ return 0;
+}
+
+void kgdb_remove_all_hw_break(void)
+{
+ int i;
+
+ for (i = 0; i < 4; i++) {
+ if (breakinfo[i].enabled) {
+ /* Do what? */
+ ;
+ }
+ memset(&breakinfo[i], 0, sizeof(struct hw_breakpoint));
+ }
+}
+
+int kgdb_set_hw_break(unsigned long addr)
+{
+ int i, idx = -1;
+ for (i = 0; i < 4; i++) {
+ if (!breakinfo[i].enabled) {
+ idx = i;
+ break;
+ }
+ }
+ if (idx == -1)
+ return -1;
+
+ breakinfo[idx].enabled = 1;
+ breakinfo[idx].type = 1;
+ breakinfo[idx].len = 1;
+ breakinfo[idx].addr = addr;
+ return 0;
+}
+
void kgdb_disable_hw_debug(struct pt_regs *regs)
{
/* Disable hardware debugging while we are in kgdb */
@@ -298,4 +346,5 @@ int kgdb_arch_init(void)

struct kgdb_arch arch_kgdb_ops = {
.gdb_bpt_instr = {0xcc},
+ .flags = KGDB_HW_BREAKPOINT,
};
_
-
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