On 2024/7/15 22:48, Baoquan He wrote: > On 07/13/24 at 09:48am, Jinjie Ruan wrote: >> On x86_32 Qemu machine with 1GB memory, the cmdline "crashkernel=4G" is ok >> as below: >> crashkernel reserved: 0x0000000020000000 - 0x0000000120000000 (4096 MB) >> >> And on Qemu vexpress-a9 with 1GB memory, the crash kernel "crashkernel=4G" >> is also ok as below: >> Reserving 4096MB of memory at 2432MB for crashkernel (System RAM: 1024MB) >> >> The cause is that the crash_size is parsed and printed with "unsigned long >> long" data type which is 8 bytes but allocated used with "phys_addr_t" >> which is 4 bytes in memblock_phys_alloc_range(). >> >> Fix it by limiting the "crash_size" to phys_addr_t and bypass the invalid >> input size. > > I am not sure if this is a good idea. Shouldn't we handle this in > arch_reserve_crashkernel() to check the system RAM size? > > With this patch, if you specify crashkernel=4352M (namely 4G+256M) in > kernel cmdline, then you will reserve 256M crashkernel in system, don't > you think that is confusing? > > By the way, I am considering changing code to apply generic crashkernel > reservation to 32bit system. Maybe below draft code can prevent > crashkernel=,high from being parsed successfully on 32bit system. > > What do you think? I'll test the below patch on ARM32 an x86_32 sooner. > > 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. > > _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
