From 8d56e5c5a99ce1d17d39ce5a8260e42c2a2d7682 Mon Sep 17 00:00:00 2001 From: Alexandru Elisei Date: Mon, 25 Apr 2022 12:44:42 +0100 Subject: arm64: Treat ESR_ELx as a 64-bit register In the initial release of the ARM Architecture Reference Manual for ARMv8-A, the ESR_ELx registers were defined as 32-bit registers. This changed in 2018 with version D.a (ARM DDI 0487D.a) of the architecture, when they became 64-bit registers, with bits [63:32] defined as RES0. In version G.a, a new field was added to ESR_ELx, ISS2, which covers bits [36:32]. This field is used when the Armv8.7 extension FEAT_LS64 is implemented. As a result of the evolution of the register width, Linux stores it as both a 64-bit value and a 32-bit value, which hasn't affected correctness so far as Linux only uses the lower 32 bits of the register. Make the register type consistent and always treat it as 64-bit wide. The register is redefined as an "unsigned long", which is an unsigned double-word (64-bit quantity) for the LP64 machine (aapcs64 [1], Table 1, page 14). The type was chosen because "unsigned int" is the most frequent type for ESR_ELx and because FAR_ELx, which is used together with ESR_ELx in exception handling, is also declared as "unsigned long". The 64-bit type also makes adding support for architectural features that use fields above bit 31 easier in the future. The KVM hypervisor will receive a similar update in a subsequent patch. [1] https://github.com/ARM-software/abi-aa/releases/download/2021Q3/aapcs64.pdf Signed-off-by: Alexandru Elisei Reviewed-by: Marc Zyngier Link: https://lore.kernel.org/r/20220425114444.368693-4-alexandru.elisei@arm.com Signed-off-by: Catalin Marinas --- arch/arm64/kernel/probes/kprobes.c | 4 ++-- arch/arm64/kernel/probes/uprobes.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) (limited to 'arch/arm64/kernel/probes') diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c index d9dfa82c1f18..d1d182320245 100644 --- a/arch/arm64/kernel/probes/kprobes.c +++ b/arch/arm64/kernel/probes/kprobes.c @@ -335,7 +335,7 @@ static void __kprobes kprobe_handler(struct pt_regs *regs) } static int __kprobes -kprobe_breakpoint_ss_handler(struct pt_regs *regs, unsigned int esr) +kprobe_breakpoint_ss_handler(struct pt_regs *regs, unsigned long esr) { struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); unsigned long addr = instruction_pointer(regs); @@ -359,7 +359,7 @@ static struct break_hook kprobes_break_ss_hook = { }; static int __kprobes -kprobe_breakpoint_handler(struct pt_regs *regs, unsigned int esr) +kprobe_breakpoint_handler(struct pt_regs *regs, unsigned long esr) { kprobe_handler(regs); return DBG_HOOK_HANDLED; diff --git a/arch/arm64/kernel/probes/uprobes.c b/arch/arm64/kernel/probes/uprobes.c index 9be668f3f034..d49aef2657cd 100644 --- a/arch/arm64/kernel/probes/uprobes.c +++ b/arch/arm64/kernel/probes/uprobes.c @@ -166,7 +166,7 @@ int arch_uprobe_exception_notify(struct notifier_block *self, } static int uprobe_breakpoint_handler(struct pt_regs *regs, - unsigned int esr) + unsigned long esr) { if (uprobe_pre_sstep_notifier(regs)) return DBG_HOOK_HANDLED; @@ -175,7 +175,7 @@ static int uprobe_breakpoint_handler(struct pt_regs *regs, } static int uprobe_single_step_handler(struct pt_regs *regs, - unsigned int esr) + unsigned long esr) { struct uprobe_task *utask = current->utask; -- cgit v1.2.3