[PATCH 1/2] riscv, crash: don't export some symbols when CONFIG_MMU=n

Baoquan He
2023-12-04T02:19:58Z

When dropping select of KEXEC and dependency on ARCH_SUPPORTS_KEXEC
from CRASH_DUMP, compiling error is reported when below config items are
set:
-----------------------
CONFIG_CRASH_CORE=y
CONFIG_KEXEC_CORE=y
CONFIG_CRASH_DUMP=y
......
-----------------------

-------------------------------------------------------------------------------------------------
arch/riscv/kernel/crash_core.c:8:27: error: 'VA_BITS' undeclared (first use in this function)
8 | VMCOREINFO_NUMBER(VA_BITS);
| ^~~~~~~
include/linux/crash_core.h:78:64: note: in definition of macro 'VMCOREINFO_NUMBER'
78 | vmcoreinfo_append_str("NUMBER(%s)=%ld\n", #name, (long)name)
| ^~~~

arch/riscv/kernel/crash_core.c:14:64: error: 'VMEMMAP_START' undeclared (first use in this function)
14 | vmcoreinfo_append_str("NUMBER(VMEMMAP_START)=0x%lx\n", VMEMMAP_START);
| ^~~~~~~~~~~~~
arch/riscv/kernel/crash_core.c:15:62: error: 'VMEMMAP_END' undeclared (first use in this function); did you mean 'MEMREMAP_ENC'?
15 | vmcoreinfo_append_str("NUMBER(VMEMMAP_END)=0x%lx\n", VMEMMAP_END);
| ^~~~~~~~~~~
| MEMREMAP_ENC
arch/riscv/kernel/crash_core.c:17:64: error: 'MODULES_VADDR' undeclared (first use in this function)
17 | vmcoreinfo_append_str("NUMBER(MODULES_VADDR)=0x%lx\n", MODULES_VADDR);
| ^~~~~~~~~~~~~
arch/riscv/kernel/crash_core.c:18:62: error: 'MODULES_END' undeclared (first use in this function)
18 | vmcoreinfo_append_str("NUMBER(MODULES_END)=0x%lx\n", MODULES_END);
-------------------------------------------------------------------------------------------------

Currently, riscv's ARCH_SUPPORTS_KEXEC has dependency on MMU. Before
dropping ARCH_SUPPORTS_KEXEC, disabling CONFIG_MMU will unset
CONFIG_CRASH_DUMP, CONFIG_KEXEC_CORE, CONFIG_CRASH_CORE. Hence
crash_core related codes won't be compiled.

---------------------
arch/riscv/Kconfig:
config ARCH_SUPPORTS_KEXEC
def_bool MMU
---------------------

After dropping ARCH_SUPPORTS_KEXEC, CONFIG_CRASH_DUMP, CONFIG_KEXEC_CORE,
CONFIG_CRASH_CORE can be set independently of CONFIG_MMU. However, there
are several macro definitions, such as VA_BITS, VMEMMAP_START, VMEMMAP_END,
MODULES_VADDR, MODULES_END are only available when CONFIG_MMU=y. Then
compiling errors are triggered.

Here, add CONFIG_MMU ifdeffery in arch_crash_save_vmcoreinfo() to export
those symbols when CONFIG_MMU is enabled.

Signed-off-by: Baoquan He <bhe@redhat.com>
---
arch/riscv/kernel/crash_core.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/kernel/crash_core.c b/arch/riscv/kernel/crash_core.c
index 55f1d7856b54..8706736fd4e2 100644
--- a/arch/riscv/kernel/crash_core.c
+++ b/arch/riscv/kernel/crash_core.c
@@ -5,17 +5,19 @@

void arch_crash_save_vmcoreinfo(void)
{
- VMCOREINFO_NUMBER(VA_BITS);
VMCOREINFO_NUMBER(phys_ram_base);

vmcoreinfo_append_str("NUMBER(PAGE_OFFSET)=0x%lx\n", PAGE_OFFSET);
vmcoreinfo_append_str("NUMBER(VMALLOC_START)=0x%lx\n", VMALLOC_START);
vmcoreinfo_append_str("NUMBER(VMALLOC_END)=0x%lx\n", VMALLOC_END);
+#ifdef CONFIG_MMU
+ VMCOREINFO_NUMBER(VA_BITS);
vmcoreinfo_append_str("NUMBER(VMEMMAP_START)=0x%lx\n", VMEMMAP_START);
vmcoreinfo_append_str("NUMBER(VMEMMAP_END)=0x%lx\n", VMEMMAP_END);
#ifdef CONFIG_64BIT
vmcoreinfo_append_str("NUMBER(MODULES_VADDR)=0x%lx\n", MODULES_VADDR);
vmcoreinfo_append_str("NUMBER(MODULES_END)=0x%lx\n", MODULES_END);
+#endif
#endif
vmcoreinfo_append_str("NUMBER(KERNEL_LINK_ADDR)=0x%lx\n", KERNEL_LINK_ADDR);
vmcoreinfo_append_str("NUMBER(va_kernel_pa_offset)=0x%lx\n",
--
2.41.0