On x86_32 Qemu machine with 1GB memory, the cmdline "crashkernel=4G" is ok as below: crashkernel reserved: 0x0000000020000000 - 0x0000000120000000 (4096 MB) It's similar on other architectures, such as ARM32 and RISCV32. 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 checking if crash_size is greater than system RAM size and return error if so. After this patch, there is no above confusing reserve success info. Signed-off-by: Jinjie Ruan <ruanjinjie@xxxxxxxxxx> Suggested-by: Mike Rapoport <rppt@xxxxxxxxxx> Acked-by: Baoquan He <bhe@xxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- v6: - Take off Baoquan's Suggested-by. v5: - Fix it in common parse_crashkernel() instead of per-arch. - Add suggested-by. v4: - Update the warn info to align with parse_crashkernel_mem(). - Rebased on the "ARM: Use generic interface to simplify crashkernel reservation" patch. - Also fix for riscv32. - Update the commit message. v3: - Handle the check in reserve_crashkernel() Baoquan suggested. - Split x86_32 and arm32. - Add Suggested-by. - Drop the wrong fix tag. v2: - Also fix for x86_32. - Update the fix method. - Peel off the other two patches. - Update the commit message. --- kernel/crash_reserve.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/crash_reserve.c b/kernel/crash_reserve.c index ad5b3f2c5487..5387269114f6 100644 --- a/kernel/crash_reserve.c +++ b/kernel/crash_reserve.c @@ -335,6 +335,9 @@ int __init parse_crashkernel(char *cmdline, if (!*crash_size) ret = -EINVAL; + if (*crash_size >= system_ram) + ret = -EINVAL; + return ret; } -- 2.34.1 _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec