mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-22 10:31:08 +00:00
8252ca87c7
Enabling function_graph tracer on ARM causes kernel panic, because the
function graph tracer updates the "return address" of a function in order
to insert a trace callback on function exit, it saves the function's
original return address in a return trace stack, but cpu_suspend() may not
return through the normal return path.
cpu_suspend() will resume directly via the cpu_resume path, but the return
trace stack has been set-up by the subfunctions of cpu_suspend(), which
makes the "return address" inconsistent with cpu_suspend().
This patch refers to Commit de818bd452
("arm64: kernel: pause/unpause function graph tracer in cpu_suspend()"),
fixes the issue by pausing/resuming the function graph tracer on the thread
executing cpu_suspend(), so that the function graph tracer state is kept
consistent across functions that enter power down states and never return
by effectively disabling graph tracer while they are executing.
Signed-off-by: louis.wang <liang26812@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
122 lines
3.1 KiB
C
122 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
#include <linux/ftrace.h>
|
|
#include <linux/init.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/mm_types.h>
|
|
#include <linux/pgtable.h>
|
|
|
|
#include <asm/bugs.h>
|
|
#include <asm/cacheflush.h>
|
|
#include <asm/idmap.h>
|
|
#include <asm/memory.h>
|
|
#include <asm/smp_plat.h>
|
|
#include <asm/suspend.h>
|
|
#include <asm/tlbflush.h>
|
|
|
|
extern int __cpu_suspend(unsigned long, int (*)(unsigned long), u32 cpuid);
|
|
extern void cpu_resume_mmu(void);
|
|
|
|
#ifdef CONFIG_MMU
|
|
int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
|
|
{
|
|
struct mm_struct *mm = current->active_mm;
|
|
u32 __mpidr = cpu_logical_map(smp_processor_id());
|
|
int ret;
|
|
|
|
if (!idmap_pgd)
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* Function graph tracer state gets incosistent when the kernel
|
|
* calls functions that never return (aka suspend finishers) hence
|
|
* disable graph tracing during their execution.
|
|
*/
|
|
pause_graph_tracing();
|
|
|
|
/*
|
|
* Provide a temporary page table with an identity mapping for
|
|
* the MMU-enable code, required for resuming. On successful
|
|
* resume (indicated by a zero return code), we need to switch
|
|
* back to the correct page tables.
|
|
*/
|
|
ret = __cpu_suspend(arg, fn, __mpidr);
|
|
|
|
unpause_graph_tracing();
|
|
|
|
if (ret == 0) {
|
|
cpu_switch_mm(mm->pgd, mm);
|
|
local_flush_bp_all();
|
|
local_flush_tlb_all();
|
|
check_other_bugs();
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
#else
|
|
int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
|
|
{
|
|
u32 __mpidr = cpu_logical_map(smp_processor_id());
|
|
int ret;
|
|
|
|
pause_graph_tracing();
|
|
ret = __cpu_suspend(arg, fn, __mpidr);
|
|
unpause_graph_tracing();
|
|
|
|
return ret;
|
|
}
|
|
#define idmap_pgd NULL
|
|
#endif
|
|
|
|
/*
|
|
* This is called by __cpu_suspend() to save the state, and do whatever
|
|
* flushing is required to ensure that when the CPU goes to sleep we have
|
|
* the necessary data available when the caches are not searched.
|
|
*/
|
|
void __cpu_suspend_save(u32 *ptr, u32 ptrsz, u32 sp, u32 *save_ptr)
|
|
{
|
|
u32 *ctx = ptr;
|
|
|
|
*save_ptr = virt_to_phys(ptr);
|
|
|
|
/* This must correspond to the LDM in cpu_resume() assembly */
|
|
*ptr++ = virt_to_phys(idmap_pgd);
|
|
*ptr++ = sp;
|
|
*ptr++ = virt_to_phys(cpu_do_resume);
|
|
|
|
cpu_do_suspend(ptr);
|
|
|
|
flush_cache_louis();
|
|
|
|
/*
|
|
* flush_cache_louis does not guarantee that
|
|
* save_ptr and ptr are cleaned to main memory,
|
|
* just up to the Level of Unification Inner Shareable.
|
|
* Since the context pointer and context itself
|
|
* are to be retrieved with the MMU off that
|
|
* data must be cleaned from all cache levels
|
|
* to main memory using "area" cache primitives.
|
|
*/
|
|
__cpuc_flush_dcache_area(ctx, ptrsz);
|
|
__cpuc_flush_dcache_area(save_ptr, sizeof(*save_ptr));
|
|
|
|
outer_clean_range(*save_ptr, *save_ptr + ptrsz);
|
|
outer_clean_range(virt_to_phys(save_ptr),
|
|
virt_to_phys(save_ptr) + sizeof(*save_ptr));
|
|
}
|
|
|
|
extern struct sleep_save_sp sleep_save_sp;
|
|
|
|
static int cpu_suspend_alloc_sp(void)
|
|
{
|
|
void *ctx_ptr;
|
|
/* ctx_ptr is an array of physical addresses */
|
|
ctx_ptr = kcalloc(mpidr_hash_size(), sizeof(u32), GFP_KERNEL);
|
|
|
|
if (WARN_ON(!ctx_ptr))
|
|
return -ENOMEM;
|
|
sleep_save_sp.save_ptr_stash = ctx_ptr;
|
|
sleep_save_sp.save_ptr_stash_phys = virt_to_phys(ctx_ptr);
|
|
sync_cache_w(&sleep_save_sp);
|
|
return 0;
|
|
}
|
|
early_initcall(cpu_suspend_alloc_sp);
|