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authorRussell King (Oracle) <rmk+kernel@armlinux.org.uk>2022-02-16 15:37:38 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-03-08 19:12:48 +0100
commitf14a0244b1ba828d2cb95a1cd2ac3157db4213b7 (patch)
treeaa820c379c6c69f14995cd2566ebc5ce9aefeac4 /arch/arm/kernel
parentc9cfcdd111d7f82831ec9f205f4370427739b9d5 (diff)
ARM: Fix kgdb breakpoint for Thumb2
commit d920eaa4c4559f59be7b4c2d26fa0a2e1aaa3da9 upstream. The kgdb code needs to register an undef hook for the Thumb UDF instruction that will fault in order to be functional on Thumb2 platforms. Reported-by: Johannes Stezenbach <js@sig21.net> Tested-by: Johannes Stezenbach <js@sig21.net> Fixes: 5cbad0ebf45c ("kgdb: support for ARCH=arm") Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm/kernel')
-rw-r--r--arch/arm/kernel/kgdb.c36
1 files changed, 28 insertions, 8 deletions
diff --git a/arch/arm/kernel/kgdb.c b/arch/arm/kernel/kgdb.c
index 7bd30c0a4280..22f937e6f3ff 100644
--- a/arch/arm/kernel/kgdb.c
+++ b/arch/arm/kernel/kgdb.c
@@ -154,22 +154,38 @@ static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int instr)
return 0;
}
-static struct undef_hook kgdb_brkpt_hook = {
+static struct undef_hook kgdb_brkpt_arm_hook = {
.instr_mask = 0xffffffff,
.instr_val = KGDB_BREAKINST,
- .cpsr_mask = MODE_MASK,
+ .cpsr_mask = PSR_T_BIT | MODE_MASK,
.cpsr_val = SVC_MODE,
.fn = kgdb_brk_fn
};
-static struct undef_hook kgdb_compiled_brkpt_hook = {
+static struct undef_hook kgdb_brkpt_thumb_hook = {
+ .instr_mask = 0xffff,
+ .instr_val = KGDB_BREAKINST & 0xffff,
+ .cpsr_mask = PSR_T_BIT | MODE_MASK,
+ .cpsr_val = PSR_T_BIT | SVC_MODE,
+ .fn = kgdb_brk_fn
+};
+
+static struct undef_hook kgdb_compiled_brkpt_arm_hook = {
.instr_mask = 0xffffffff,
.instr_val = KGDB_COMPILED_BREAK,
- .cpsr_mask = MODE_MASK,
+ .cpsr_mask = PSR_T_BIT | MODE_MASK,
.cpsr_val = SVC_MODE,
.fn = kgdb_compiled_brk_fn
};
+static struct undef_hook kgdb_compiled_brkpt_thumb_hook = {
+ .instr_mask = 0xffff,
+ .instr_val = KGDB_COMPILED_BREAK & 0xffff,
+ .cpsr_mask = PSR_T_BIT | MODE_MASK,
+ .cpsr_val = PSR_T_BIT | SVC_MODE,
+ .fn = kgdb_compiled_brk_fn
+};
+
static int __kgdb_notify(struct die_args *args, unsigned long cmd)
{
struct pt_regs *regs = args->regs;
@@ -210,8 +226,10 @@ int kgdb_arch_init(void)
if (ret != 0)
return ret;
- register_undef_hook(&kgdb_brkpt_hook);
- register_undef_hook(&kgdb_compiled_brkpt_hook);
+ register_undef_hook(&kgdb_brkpt_arm_hook);
+ register_undef_hook(&kgdb_brkpt_thumb_hook);
+ register_undef_hook(&kgdb_compiled_brkpt_arm_hook);
+ register_undef_hook(&kgdb_compiled_brkpt_thumb_hook);
return 0;
}
@@ -224,8 +242,10 @@ int kgdb_arch_init(void)
*/
void kgdb_arch_exit(void)
{
- unregister_undef_hook(&kgdb_brkpt_hook);
- unregister_undef_hook(&kgdb_compiled_brkpt_hook);
+ unregister_undef_hook(&kgdb_brkpt_arm_hook);
+ unregister_undef_hook(&kgdb_brkpt_thumb_hook);
+ unregister_undef_hook(&kgdb_compiled_brkpt_arm_hook);
+ unregister_undef_hook(&kgdb_compiled_brkpt_thumb_hook);
unregister_die_notifier(&kgdb_notifier);
}