mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-05 06:26:55 +07:00
d224a69e3d
sysrq_handle_reboot() re-enables interrupts while on the irq stack. The irq_stack implementation wrongly assumed this would only ever happen via the softirq path, allowing it to update irq_count late, in do_softirq_own_stack(). This means if an irq occurs in sysrq_handle_reboot(), during emergency_restart() the stack will be corrupted, as irq_count wasn't updated. Lose the optimisation, and instead of moving the adding/subtracting of irq_count into irq_stack_entry/irq_stack_exit, remove it, and compare sp_el0 (struct thread_info) with sp & ~(THREAD_SIZE - 1). This tells us if we are on a task stack, if so, we can safely switch to the irq stack. Finally, remove do_softirq_own_stack(), we don't need it anymore. Reported-by: Will Deacon <will.deacon@arm.com> Signed-off-by: James Morse <james.morse@arm.com> [will: use get_thread_info macro] Signed-off-by: Will Deacon <will.deacon@arm.com>
61 lines
1.5 KiB
C
61 lines
1.5 KiB
C
#ifndef __ASM_IRQ_H
|
|
#define __ASM_IRQ_H
|
|
|
|
#define IRQ_STACK_SIZE THREAD_SIZE
|
|
#define IRQ_STACK_START_SP THREAD_START_SP
|
|
|
|
#ifndef __ASSEMBLER__
|
|
|
|
#include <linux/percpu.h>
|
|
|
|
#include <asm-generic/irq.h>
|
|
#include <asm/thread_info.h>
|
|
|
|
struct pt_regs;
|
|
|
|
DECLARE_PER_CPU(unsigned long [IRQ_STACK_SIZE/sizeof(long)], irq_stack);
|
|
|
|
/*
|
|
* The highest address on the stack, and the first to be used. Used to
|
|
* find the dummy-stack frame put down by el?_irq() in entry.S, which
|
|
* is structured as follows:
|
|
*
|
|
* ------------
|
|
* | | <- irq_stack_ptr
|
|
* top ------------
|
|
* | x19 | <- irq_stack_ptr - 0x08
|
|
* ------------
|
|
* | x29 | <- irq_stack_ptr - 0x10
|
|
* ------------
|
|
*
|
|
* where x19 holds a copy of the task stack pointer where the struct pt_regs
|
|
* from kernel_entry can be found.
|
|
*
|
|
*/
|
|
#define IRQ_STACK_PTR(cpu) ((unsigned long)per_cpu(irq_stack, cpu) + IRQ_STACK_START_SP)
|
|
|
|
/*
|
|
* The offset from irq_stack_ptr where entry.S will store the original
|
|
* stack pointer. Used by unwind_frame() and dump_backtrace().
|
|
*/
|
|
#define IRQ_STACK_TO_TASK_STACK(ptr) (*((unsigned long *)((ptr) - 0x08)))
|
|
|
|
extern void set_handle_irq(void (*handle_irq)(struct pt_regs *));
|
|
|
|
static inline int nr_legacy_irqs(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline bool on_irq_stack(unsigned long sp, int cpu)
|
|
{
|
|
/* variable names the same as kernel/stacktrace.c */
|
|
unsigned long low = (unsigned long)per_cpu(irq_stack, cpu);
|
|
unsigned long high = low + IRQ_STACK_START_SP;
|
|
|
|
return (low <= sp && sp <= high);
|
|
}
|
|
|
|
#endif /* !__ASSEMBLER__ */
|
|
#endif
|