[PATCH v2] arm64: add the printing of tpidr_elx in __show_regs()

Zhen Lei
2022-03-16T06:26:04Z

Commit 7158627686f0 ("arm64: percpu: implement optimised pcpu access
using tpidr_el1") and commit 6d99b68933fb ("arm64: alternatives: use
tpidr_el2 on VHE hosts") use tpidr_elx to cache my_cpu_offset to optimize
pcpu access. However, when performing reverse execution based on the
registers and the memory contents in kdump, this information is sometimes
required if there is a pcpu access.

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
---
arch/arm64/kernel/process.c | 11 +++++++++++
1 file changed, 11 insertions(+)

v1 --> v2:
Directly print the tpidr_elx register of the current exception level.
Avoid coupling with the implementation of 'my_cpu_offset'.

diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 5369e649fa79ff8..738932e6fa4e947 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -216,6 +216,17 @@ void __show_regs(struct pt_regs *regs)
show_regs_print_info(KERN_DEFAULT);
print_pstate(regs);

+ switch (read_sysreg(CurrentEL)) {
+ case CurrentEL_EL1:
+ printk("tpidr_el1 : %016llx\n", read_sysreg(TPIDR_EL1));
+ break;
+ case CurrentEL_EL2:
+ printk("tpidr_el2 : %016llx\n", read_sysreg(TPIDR_EL2));
+ break;
+ default:
+ break;
+ }
+
if (!user_mode(regs)) {
printk("pc : %pS\n", (void *)regs->pc);
printk("lr : %pS\n", (void *)ptrauth_strip_insn_pac(lr));
--
2.25.1