[PATCH] arm: Define arch_is_kernel_initmem_freed() for lockdep
From: Jan Kardell <hidden>
Date: 2021-03-29 17:54:16
Also in:
linux-mm, linux-omap, lkml
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
This fixes the warning:
WARNING: CPU: 0 PID: 1994 at kernel/locking/lockdep.c:1119 alloc_netdev_mqs+0xb4/0x3b0
This warning is because the check in static_obj() assumes that all
memory within [_stext, _end] belongs to static objects. The init
section is also part of this range, and freeing it allows the buddy
allocator to allocate memory from it.
To fix this, define arch_is_kernel_initmem_freed() for arm, it will
return 1 if initmem has been freed and the address is in the range
[__init_begin, __init_end], and this function is called by the
static_obj() function in lockdep.
Tested on TI am3352 (Cortex A8).
This change is modelled after commit 7a5da02de8d6eafba995
("locking/lockdep: check for freed initmem in static_obj()") for s390 by
Gerald Schaefer [off-list ref]
Signed-off-by: Jan Kardell <redacted>
---
arch/arm/include/asm/sections.h | 13 +++++++++++++
arch/arm/mm/init.c | 6 +++++-
2 files changed, 18 insertions(+), 1 deletion(-)
diff --git a/arch/arm/include/asm/sections.h b/arch/arm/include/asm/sections.h
index 700b8bcdf9bd..1dd64c90c1ac 100644
--- a/arch/arm/include/asm/sections.h
+++ b/arch/arm/include/asm/sections.h@@ -2,6 +2,8 @@ #ifndef _ASM_ARM_SECTIONS_H #define _ASM_ARM_SECTIONS_H +#define arch_is_kernel_initmem_freed arch_is_kernel_initmem_freed + #include <asm-generic/sections.h> extern char _exiprom[];
@@ -11,6 +13,17 @@ extern char __idmap_text_end[]; extern char __entry_text_start[]; extern char __entry_text_end[]; +extern bool initmem_freed; + +static inline int arch_is_kernel_initmem_freed(unsigned long addr) +{ + if (!initmem_freed) + return 0; + return addr >= (unsigned long)__init_begin && + addr < (unsigned long)__init_end; +} + + static inline bool in_entry_text(unsigned long addr) { return memory_contains(__entry_text_start, __entry_text_end,
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 828a2561b229..cd7a4273797a 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c@@ -41,6 +41,8 @@ #include "mm.h" +bool initmem_freed; + #ifdef CONFIG_CPU_CP15_MMU unsigned long __init __clear_cr(unsigned long mask) {
@@ -523,8 +525,10 @@ void free_initmem(void) fix_kernmem_perms(); poison_init_mem(__init_begin, __init_end - __init_begin); - if (!machine_is_integrator() && !machine_is_cintegrator()) + if (!machine_is_integrator() && !machine_is_cintegrator()) { + initmem_freed = true; free_initmem_default(-1); + } } #ifdef CONFIG_BLK_DEV_INITRD
--
2.26.2
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