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Commit 453b7740 authored by Will Deacon's avatar Will Deacon
Browse files

arm64: probes: Move magic BRK values into brk-imm.h 



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: default avatarMark Rutland <mark.rutland@arm.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent fb610f2a

arch/arm64/include/asm/brk-imm.h

+4 −0
Original line number Diff line number Diff line
@@ -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

arch/arm64/include/asm/debug-monitors.h

+2 −5
Original line number Diff line number Diff line
@@ -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

arch/arm64/include/asm/esr.h

+1 −3
Original line number Diff line number Diff line
@@ -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

arch/arm64/kernel/debug-monitors.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

arch/arm64/kernel/probes/kprobes.c

+1 −1
Original line number Diff line number Diff line
@@ -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,

};