diff options
| author | Xin Li (Intel) <xin@zytor.com> | 2024-07-09 08:40:48 -0700 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2024-08-13 21:59:21 +0200 |
| commit | a97756cbec448032f84b5bbfe4e101478d1e01e0 (patch) | |
| tree | bf0516b1c5eeb8226f205593e3f0e265f03c0f79 /arch/x86/kernel/cpu/common.c | |
| parent | 73270c1f2369fb37683121ebe097cd37172602b6 (diff) | |
x86/fred: Enable FRED right after init_mem_mapping()
On 64-bit init_mem_mapping() relies on the minimal page fault handler
provided by the early IDT mechanism. The real page fault handler is
installed right afterwards into the IDT.
This is problematic on CPUs which have X86_FEATURE_FRED set because the
real page fault handler retrieves the faulting address from the FRED
exception stack frame and not from CR2, but that does obviously not work
when FRED is not yet enabled in the CPU.
To prevent this enable FRED right after init_mem_mapping() without
interrupt stacks. Those are enabled later in trap_init() after the CPU
entry area is set up.
[ tglx: Encapsulate the FRED details ]
Fixes: 14619d912b65 ("x86/fred: FRED entry/exit and dispatch code")
Reported-by: Hou Wenlong <houwenlong.hwl@antgroup.com>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Xin Li (Intel) <xin@zytor.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20240709154048.3543361-4-xin@zytor.com
Diffstat (limited to 'arch/x86/kernel/cpu/common.c')
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 6de12b3c1b04..a4735d9b5a1d 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -2176,7 +2176,7 @@ static inline void tss_setup_io_bitmap(struct tss_struct *tss) * Setup everything needed to handle exceptions from the IDT, including the IST * exceptions which use paranoid_entry(). */ -void cpu_init_exception_handling(void) +void cpu_init_exception_handling(bool boot_cpu) { struct tss_struct *tss = this_cpu_ptr(&cpu_tss_rw); int cpu = raw_smp_processor_id(); @@ -2196,13 +2196,24 @@ void cpu_init_exception_handling(void) setup_ghcb(); if (cpu_feature_enabled(X86_FEATURE_FRED)) { - cpu_init_fred_exceptions(); + /* The boot CPU has enabled FRED during early boot */ + if (!boot_cpu) + cpu_init_fred_exceptions(); + cpu_init_fred_rsps(); } else { load_current_idt(); } } +void __init cpu_init_replace_early_idt(void) +{ + if (cpu_feature_enabled(X86_FEATURE_FRED)) + cpu_init_fred_exceptions(); + else + idt_setup_early_pf(); +} + /* * cpu_init() initializes state that is per-CPU. Some data is already * initialized (naturally) in the bootstrap process, such as the GDT. We |