Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 8deaf923 authored by Marc Zyngier's avatar Marc Zyngier Committed by Gerrit - the friendly Code Review server
Browse files

arm64: compat: Add CNTFRQ trap handler 



Just like CNTVCT, we need to handle userspace trapping into the
kernel if we're decided that the timer wasn't fit for purpose...
64bit userspace is already dealt with, but we're missing the
equivalent compat handling.

Change-Id: I01aacdddfc5f4c8503a5182bd489f9b91dce476c
Reviewed-by: default avatarMark Rutland <mark.rutland@arm.com>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Git-commit: 32a3e635fb0ecc1b197d54f710e76c6481cf19f0
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Signed-off-by: default avatarNeeraj Upadhyay <neeraju@codeaurora.org>
parent 26ce6b8b

arch/arm64/include/asm/esr.h

+3 −0
Original line number Diff line number Diff line
@@ -304,6 +304,9 @@ 
#define ESR_ELx_CP15_64_ISS_SYS_CNTVCT	(ESR_ELx_CP15_64_ISS_SYS_VAL(1, 14) | \

					 ESR_ELx_CP15_64_ISS_DIR_READ)



#define ESR_ELx_CP15_32_ISS_SYS_CNTFRQ	(ESR_ELx_CP15_32_ISS_SYS_VAL(0, 0, 14, 0) |\

					 ESR_ELx_CP15_32_ISS_DIR_READ)



#ifndef __ASSEMBLY__

#include <asm/types.h>

arch/arm64/kernel/traps.c

+13 −0
Original line number Diff line number Diff line
@@ -612,7 +612,20 @@ static void arm64_compat_skip_faulting_instruction(struct pt_regs *regs, 
	arm64_skip_faulting_instruction(regs, sz);

}



static void compat_cntfrq_read_handler(unsigned int esr, struct pt_regs *regs)

{

	int reg = (esr & ESR_ELx_CP15_32_ISS_RT_MASK) >> ESR_ELx_CP15_32_ISS_RT_SHIFT;



	pt_regs_write_reg(regs, reg, arch_timer_get_rate());

	arm64_compat_skip_faulting_instruction(regs, 4);

}



static struct sys64_hook cp15_32_hooks[] = {

	{

		.esr_mask = ESR_ELx_CP15_32_ISS_SYS_MASK,

		.esr_val = ESR_ELx_CP15_32_ISS_SYS_CNTFRQ,

		.handler = compat_cntfrq_read_handler,

	},

	{},

};