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arm64: kgdb: handle read-only text / modules

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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 2f896d5866 ("arm64: use fixmap for text patching") in 4.0.

Fixes: 11d91a770f ("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>
This commit is contained in:
AKASHI Takahiro 2016-09-23 16:42:08 +09:00 committed by Catalin Marinas
parent c18df0adab
commit 67787b68ec
2 changed files with 24 additions and 14 deletions
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2
arch/arm64/include/asm/debug-monitors.h
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@ -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

36
arch/arm64/kernel/kgdb.c
View File

@ -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);
}