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authorAKASHI Takahiro <takahiro.akashi@linaro.org>2016-09-23 16:42:08 +0900
committerCatalin Marinas <catalin.marinas@arm.com>2016-09-23 11:25:01 +0100
commit67787b68ec48c239d5ec12f9bf5adaf5c459517a (patch)
tree807c1243a2458bb8a83d527c4970ad48840f87ee /arch
parentc18df0adabf8400c1825b90382d06df5edc303fa (diff)
downloadlinux-stericsson-67787b68ec48c239d5ec12f9bf5adaf5c459517a.tar.gz
arm64: kgdb: handle read-only text / modules
Handle read-only cases when CONFIG_DEBUG_RODATA (4.0) or CONFIG_DEBUG_SET_MODULE_RONX (3.18) are enabled by using aarch64_insn_write() instead of probe_kernel_write() as introduced by commit 2f896d586610 ("arm64: use fixmap for text patching") in 4.0. Fixes: 11d91a770f1f ("arm64: Add CONFIG_DEBUG_SET_MODULE_RONX support") Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm64/include/asm/debug-monitors.h2
-rw-r--r--arch/arm64/kernel/kgdb.c36
2 files changed, 24 insertions, 14 deletions
diff --git a/arch/arm64/include/asm/debug-monitors.h b/arch/arm64/include/asm/debug-monitors.h
index 4b6b3f72a215..b71420a12f26 100644
--- a/arch/arm64/include/asm/debug-monitors.h
+++ b/arch/arm64/include/asm/debug-monitors.h
@@ -61,8 +61,6 @@
#define AARCH64_BREAK_KGDB_DYN_DBG \
(AARCH64_BREAK_MON | (KGDB_DYN_DBG_BRK_IMM << 5))
-#define KGDB_DYN_BRK_INS_BYTE(x) \
- ((AARCH64_BREAK_KGDB_DYN_DBG >> (8 * (x))) & 0xff)
#define CACHE_FLUSH_IS_SAFE 1
diff --git a/arch/arm64/kernel/kgdb.c b/arch/arm64/kernel/kgdb.c
index 8c57f6496e56..e017a9493b92 100644
--- a/arch/arm64/kernel/kgdb.c
+++ b/arch/arm64/kernel/kgdb.c
@@ -19,10 +19,13 @@
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+#include <linux/bug.h>
#include <linux/irq.h>
#include <linux/kdebug.h>
#include <linux/kgdb.h>
#include <linux/kprobes.h>
+#include <asm/debug-monitors.h>
+#include <asm/insn.h>
#include <asm/traps.h>
struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = {
@@ -338,15 +341,24 @@ void kgdb_arch_exit(void)
unregister_die_notifier(&kgdb_notifier);
}
-/*
- * ARM instructions are always in LE.
- * Break instruction is encoded in LE format
- */
-struct kgdb_arch arch_kgdb_ops = {
- .gdb_bpt_instr = {
- KGDB_DYN_BRK_INS_BYTE(0),
- KGDB_DYN_BRK_INS_BYTE(1),
- KGDB_DYN_BRK_INS_BYTE(2),
- KGDB_DYN_BRK_INS_BYTE(3),
- }
-};
+struct kgdb_arch arch_kgdb_ops;
+
+int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt)
+{
+ int err;
+
+ BUILD_BUG_ON(AARCH64_INSN_SIZE != BREAK_INSTR_SIZE);
+
+ err = aarch64_insn_read((void *)bpt->bpt_addr, (u32 *)bpt->saved_instr);
+ if (err)
+ return err;
+
+ return aarch64_insn_write((void *)bpt->bpt_addr,
+ (u32)AARCH64_BREAK_KGDB_DYN_DBG);
+}
+
+int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt)
+{
+ return aarch64_insn_write((void *)bpt->bpt_addr,
+ *(u32 *)bpt->saved_instr);
+}