On x86_32 Qemu machine with 1GB memory, the cmdline "crashkernel=1G,high"
will cause system stall as below:
ACPI: Reserving FACP table memory at [mem 0x3ffe18b8-0x3ffe192b]
ACPI: Reserving DSDT table memory at [mem 0x3ffe0040-0x3ffe18b7]
ACPI: Reserving FACS table memory at [mem 0x3ffe0000-0x3ffe003f]
ACPI: Reserving APIC table memory at [mem 0x3ffe192c-0x3ffe19bb]
ACPI: Reserving HPET table memory at [mem 0x3ffe19bc-0x3ffe19f3]
ACPI: Reserving WAET table memory at [mem 0x3ffe19f4-0x3ffe1a1b]
143MB HIGHMEM available.
879MB LOWMEM available.
mapped low ram: 0 - 36ffe000
low ram: 0 - 36ffe000
(stall here)
The reason is that the CRASH_ADDR_LOW_MAX is equal to CRASH_ADDR_HIGH_MAX
on x86_32, the first high crash kernel memory reservation will fail, then
go into the "retry" loop and never came out as below.
-> reserve_crashkernel_generic() and high is true
-> alloc at [CRASH_ADDR_LOW_MAX, CRASH_ADDR_HIGH_MAX] fail
-> alloc at [0, CRASH_ADDR_LOW_MAX] fail and repeatedly
(because CRASH_ADDR_LOW_MAX = CRASH_ADDR_HIGH_MAX).
Fix it by prevent crashkernel=,high from being parsed successfully on 32bit
system with a architecture-defined macro.
After this patch, the 'crashkernel=,high' for 32bit system can't succeed,
and it has no chance to call reserve_crashkernel_generic(), therefore this
issue on x86_32 is solved.
Fixes: 9c08a2a139fe ("x86: kdump: use generic interface to simplify crashkernel reservation code")
Signed-off-by: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>
Signed-off-by: Baoquan He <bhe@xxxxxxxxxx>
Tested-by: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>
---
v3:
- Fix it as Baoquan suggested.
- Update the commit message.
v2:
- Peel off the other two patches.
- Update the commit message and fix tag.
---
arch/arm64/include/asm/crash_reserve.h | 2 ++
arch/riscv/include/asm/crash_reserve.h | 2 ++
arch/x86/include/asm/crash_reserve.h | 1 +
kernel/crash_reserve.c | 2 +-
4 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/crash_reserve.h b/arch/arm64/include/asm/crash_reserve.h
index 4afe027a4e7b..bf362c1a612f 100644
--- a/arch/arm64/include/asm/crash_reserve.h
+++ b/arch/arm64/include/asm/crash_reserve.h
@@ -7,4 +7,6 @@
#define CRASH_ADDR_LOW_MAX arm64_dma_phys_limit
#define CRASH_ADDR_HIGH_MAX (PHYS_MASK + 1)
+
+#define HAVE_ARCH_CRASHKERNEL_RESERVATION_HIGH
#endif
diff --git a/arch/riscv/include/asm/crash_reserve.h b/arch/riscv/include/asm/crash_reserve.h
index 013962e63587..8d7a8fc1d459 100644
--- a/arch/riscv/include/asm/crash_reserve.h
+++ b/arch/riscv/include/asm/crash_reserve.h
@@ -7,5 +7,7 @@
#define CRASH_ADDR_LOW_MAX dma32_phys_limit
#define CRASH_ADDR_HIGH_MAX memblock_end_of_DRAM()
+#define HAVE_ARCH_CRASHKERNEL_RESERVATION_HIGH
+
extern phys_addr_t memblock_end_of_DRAM(void);
#endif
diff --git a/arch/x86/include/asm/crash_reserve.h b/arch/x86/include/asm/crash_reserve.h
index 7835b2cdff04..24c2327f9a16 100644
--- a/arch/x86/include/asm/crash_reserve.h
+++ b/arch/x86/include/asm/crash_reserve.h
@@ -26,6 +26,7 @@ extern unsigned long swiotlb_size_or_default(void);
#else
# define CRASH_ADDR_LOW_MAX SZ_4G
# define CRASH_ADDR_HIGH_MAX SZ_64T
+#define HAVE_ARCH_CRASHKERNEL_RESERVATION_HIGH
#endif
# define DEFAULT_CRASH_KERNEL_LOW_SIZE crash_low_size_default()
diff --git a/kernel/crash_reserve.c b/kernel/crash_reserve.c
index 5b2722a93a48..c5213f123e19 100644
--- a/kernel/crash_reserve.c
+++ b/kernel/crash_reserve.c
@@ -306,7 +306,7 @@ int __init parse_crashkernel(char *cmdline,
/* crashkernel=X[@offset] */
ret = __parse_crashkernel(cmdline, system_ram, crash_size,
crash_base, NULL);
-#ifdef CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
+#ifdef HAVE_ARCH_CRASHKERNEL_RESERVATION_HIGH
/*
* If non-NULL 'high' passed in and no normal crashkernel
* setting detected, try parsing crashkernel=,high|low.
--
2.34.1
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