From mboxrd@z Thu Jan 1 00:00:00 1970 From: takahiro.akashi@linaro.org (AKASHI Takahiro) Date: Fri, 23 Sep 2016 16:42:08 +0900 Subject: [PATCH v2.1] arm64: kgdb: handle read-only text / modules Message-ID: <20160923074208.9899-1-takahiro.akashi@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Handle read-only cases (CONFIG_DEBUG_RODATA/CONFIG_DEBUG_SET_MODULE_RONX) by using aarch64_insn_write() instead of probe_kernel_write(). See how this works: commit 2f896d586610 ("arm64: use fixmap for text patching") Signed-off-by: AKASHI Takahiro Reviewed-by: Mark Rutland Cc: Catalin Marinas Cc: Will Deacon Cc: Jason Wessel Cc: # 3.18-3.19: 2f896d5: arm64: use fixmap Cc: # 3.18-3.19: f6242ca: arm64: Fix text Cc: # 4.0- --- arch/arm64/include/asm/debug-monitors.h | 2 -- arch/arm64/kernel/kgdb.c | 36 ++++++++++++++++++++++----------- 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 4b6b3f7..b71420a 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 6732a27..b06a7a2 100644 --- a/arch/arm64/kernel/kgdb.c +++ b/arch/arm64/kernel/kgdb.c @@ -19,6 +19,7 @@ * along with this program. If not, see . */ +#include #include #include #include @@ -26,6 +27,8 @@ #include #include #include +#include +#include #include #include @@ -370,15 +373,24 @@ 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); +} -- 2.10.0