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From: Will Deacon <will.deacon@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: mark.rutland@arm.com, Will Deacon <will.deacon@arm.com>
Subject: [PATCH v2 7/8] arm64: probes: Move magic BRK values into brk-imm.h
Date: Fri,  5 Apr 2019 13:40:47 +0100	[thread overview]
Message-ID: <20190405124048.3287-8-will.deacon@arm.com> (raw)
In-Reply-To: <20190405124048.3287-1-will.deacon@arm.com>

kprobes and uprobes reserve some BRK immediates for installing their
probes. Define these along with the other reservations in brk-imm.h
and rename the ESR definitions to be consistent with the others that we
already have.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/include/asm/brk-imm.h        | 4 ++++
 arch/arm64/include/asm/debug-monitors.h | 7 ++-----
 arch/arm64/include/asm/esr.h            | 4 +---
 arch/arm64/kernel/debug-monitors.c      | 2 +-
 arch/arm64/kernel/probes/kprobes.c      | 2 +-
 arch/arm64/kernel/probes/uprobes.c      | 2 +-
 arch/arm64/kernel/traps.c               | 2 +-
 7 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/arch/arm64/include/asm/brk-imm.h b/arch/arm64/include/asm/brk-imm.h
index fec9e1384641..d84294064e6a 100644
--- a/arch/arm64/include/asm/brk-imm.h
+++ b/arch/arm64/include/asm/brk-imm.h
@@ -11,6 +11,8 @@
 
 /*
  * #imm16 values used for BRK instruction generation
+ * 0x004: for installing kprobes
+ * 0x005: for installing uprobes
  * Allowed values for kgdb are 0x400 - 0x7ff
  * 0x100: for triggering a fault on purpose (reserved)
  * 0x400: for dynamic BRK instruction
@@ -18,6 +20,8 @@
  * 0x800: kernel-mode BUG() and WARN() traps
  * 0x9xx: tag-based KASAN trap (allowed values 0x900 - 0x9ff)
  */
+#define KPROBES_BRK_IMM			0x004
+#define UPROBES_BRK_IMM			0x005
 #define FAULT_BRK_IMM			0x100
 #define KGDB_DYN_DBG_BRK_IMM		0x400
 #define KGDB_COMPILED_DBG_BRK_IMM	0x401
diff --git a/arch/arm64/include/asm/debug-monitors.h b/arch/arm64/include/asm/debug-monitors.h
index 7d37cfa5cc16..0679f781696d 100644
--- a/arch/arm64/include/asm/debug-monitors.h
+++ b/arch/arm64/include/asm/debug-monitors.h
@@ -65,12 +65,9 @@
 #define CACHE_FLUSH_IS_SAFE		1
 
 /* kprobes BRK opcodes with ESR encoding  */
-#define BRK64_ESR_MASK		0xFFFF
-#define BRK64_ESR_KPROBES	0x0004
-#define BRK64_OPCODE_KPROBES	(AARCH64_BREAK_MON | (BRK64_ESR_KPROBES << 5))
+#define BRK64_OPCODE_KPROBES	(AARCH64_BREAK_MON | (KPROBES_BRK_IMM << 5))
 /* uprobes BRK opcodes with ESR encoding  */
-#define BRK64_ESR_UPROBES	0x0005
-#define BRK64_OPCODE_UPROBES	(AARCH64_BREAK_MON | (BRK64_ESR_UPROBES << 5))
+#define BRK64_OPCODE_UPROBES	(AARCH64_BREAK_MON | (UPROBES_BRK_IMM << 5))
 
 /* AArch32 */
 #define DBG_ESR_EVT_BKPT	0x4
diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h
index 52233f00d53d..3541720189c9 100644
--- a/arch/arm64/include/asm/esr.h
+++ b/arch/arm64/include/asm/esr.h
@@ -156,9 +156,7 @@
 				 ESR_ELx_WFx_ISS_WFI)
 
 /* BRK instruction trap from AArch64 state */
-#define ESR_ELx_VAL_BRK64(imm)					\
-	((ESR_ELx_EC_BRK64 << ESR_ELx_EC_SHIFT) | ESR_ELx_IL |	\
-	 ((imm) & 0xffff))
+#define ESR_ELx_BRK64_ISS_COMMENT_MASK	0xffff
 
 /* ISS field definitions for System instruction traps */
 #define ESR_ELx_SYS64_ISS_RES0_SHIFT	22
diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c
index f4d8cda8830d..2692a0a27cf3 100644
--- a/arch/arm64/kernel/debug-monitors.c
+++ b/arch/arm64/kernel/debug-monitors.c
@@ -317,7 +317,7 @@ static int call_break_hook(struct pt_regs *regs, unsigned int esr)
 
 	rcu_read_lock();
 	list_for_each_entry_rcu(hook, list, node) {
-		unsigned int comment = esr & BRK64_ESR_MASK;
+		unsigned int comment = esr & ESR_ELx_BRK64_ISS_COMMENT_MASK;
 
 		if ((comment & ~hook->mask) == hook->imm)
 			fn = hook->fn;
diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c
index 000f32d1a756..2509fcb6d404 100644
--- a/arch/arm64/kernel/probes/kprobes.c
+++ b/arch/arm64/kernel/probes/kprobes.c
@@ -470,7 +470,7 @@ kprobe_breakpoint_handler(struct pt_regs *regs, unsigned int esr)
 }
 
 static struct break_hook kprobes_break_hook = {
-	.imm = BRK64_ESR_KPROBES,
+	.imm = KPROBES_BRK_IMM,
 	.fn = kprobe_breakpoint_handler,
 };
 
diff --git a/arch/arm64/kernel/probes/uprobes.c b/arch/arm64/kernel/probes/uprobes.c
index f37ab9567676..605945eac1f8 100644
--- a/arch/arm64/kernel/probes/uprobes.c
+++ b/arch/arm64/kernel/probes/uprobes.c
@@ -191,7 +191,7 @@ static int uprobe_single_step_handler(struct pt_regs *regs,
 
 /* uprobe breakpoint handler hook */
 static struct break_hook uprobes_break_hook = {
-	.imm = BRK64_ESR_UPROBES,
+	.imm = UPROBES_BRK_IMM,
 	.fn = uprobe_breakpoint_handler,
 };
 
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 091379744d2f..74598396e0bf 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -1024,7 +1024,7 @@ int __init early_brk64(unsigned long addr, unsigned int esr,
 		struct pt_regs *regs)
 {
 #ifdef CONFIG_KASAN_SW_TAGS
-	unsigned int comment = esr & BRK64_ESR_MASK;
+	unsigned int comment = esr & ESR_ELx_BRK64_ISS_COMMENT_MASK;
 
 	if ((comment & ~KASAN_BRK_MASK) == KASAN_BRK_IMM)
 		return kasan_handler(regs, esr) != DBG_HOOK_HANDLED;
-- 
2.11.0


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  parent reply	other threads:[~2019-04-05 12:42 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-05 12:40 [PATCH v2 0/8] Rework debug exception handling code Will Deacon
2019-04-05 12:40 ` [PATCH v2 1/8] arm64: debug: Remove unused return value from do_debug_exception() Will Deacon
2019-04-05 12:40 ` [PATCH v2 2/8] arm64: debug: Rename addr parameter for non-watchpoint exception hooks Will Deacon
2019-04-05 12:40 ` [PATCH v2 3/8] arm64: debug: Remove meaningless comment Will Deacon
2019-04-05 12:40 ` [PATCH v2 4/8] arm64: debug: Separate debug hooks based on target exception level Will Deacon
2019-04-08 16:28   ` Mark Rutland
2019-04-05 12:40 ` [PATCH v2 5/8] arm64: kprobes: Avoid calling kprobes debug handlers explicitly Will Deacon
2019-04-05 12:40 ` [PATCH v2 6/8] arm64: debug: Remove redundant user_mode(regs) checks from debug handlers Will Deacon
2019-04-05 12:40 ` Will Deacon [this message]
2019-04-05 12:40 ` [PATCH v2 8/8] arm64: debug: Clean up brk_handler() Will Deacon

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