Messages in this thread Patch in this message | | | Date | Tue, 25 Feb 2020 23:33:35 +0100 | From | Thomas Gleixner <> | Subject | [patch 14/16] x86/entry: Provide IDTENTRY_CR2 |
| |
Provide a CR2 aware variant of IDTENTRY which reads CR2 right at the begin of the C entry point before invoking irq tracing and enter_from_user_mode(). This allows to move the CR2 handling to C code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- arch/x86/include/asm/idtentry.h | 45 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+)
--- a/arch/x86/include/asm/idtentry.h +++ b/arch/x86/include/asm/idtentry.h @@ -128,6 +128,48 @@ NOKPROBE_SYMBOL(func); \ static __always_inline void __##func(struct pt_regs *regs, \ unsigned long error_code) +/** + * DECLARE_IDTENTRY_CR2 - Declare functions for fault handling IDT entry points + * @vector: Vector number (ignored for C) + * @func: Function name of the entry point + * + * Declares three functions: + * - The ASM entry point: asm_##func + * - The XEN PV trap entry point: xen_##func (maybe unused) + * - The C handler called from the ASM entry point + */ +#define DECLARE_IDTENTRY_CR2(vector, func) \ + asmlinkage void asm_##func(void); \ + asmlinkage void xen_asm_##func(void); \ + __visible void func(struct pt_regs *regs, unsigned long error_code) + +/** + * DEFINE_IDTENTRY_CR2 - Emit code for fault handling IDT entry points + * @func: Function name of the entry point + * + * Same as IDTENTRY_ERRORCODE but reads CR2 before invoking + * idtentry_enter() and hands the CR2 address into the function body. + */ +#define DEFINE_IDTENTRY_CR2(func) \ +static __always_inline void __##func(struct pt_regs *regs, \ + unsigned long error_code, \ + unsigned long address); \ + \ +__visible notrace void func(struct pt_regs *regs, \ + unsigned long error_code) \ +{ \ + unsigned long address = read_cr2(); \ + \ + idtentry_enter(regs); \ + __##func (regs, error_code, address); \ + idtentry_exit(regs); \ +} \ +NOKPROBE_SYMBOL(func); \ + \ +static __always_inline void __##func(struct pt_regs *regs, \ + unsigned long error_code, \ + unsigned long address) + #ifdef CONFIG_X86_64 /** * DECLARE_IDTENTRY_IST - Declare functions for IST handling IDT entry points @@ -291,6 +333,9 @@ static __always_inline void __##func(str #define DECLARE_IDTENTRY_ERRORCODE(vector, func) \ idtentry vector asm_##func func has_error_code=1 +#define DECLARE_IDTENTRY_CR2(vector, func) \ + DECLARE_IDTENTRY_ERRORCODE(vector, func) + /* Special case for 32bit IRET 'trap'. Do not emit ASM code */ #define DECLARE_IDTENTRY_SW(vector, func)
| |