From: Hari Bathini Date: Wed, 6 Apr 2022 09:38:38 +0000 (+0530) Subject: powerpc/fadump: align destination address to pagesize X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=9cf3b3a33a36ef4a988be0a770edd3555297f2a9;p=linux.git powerpc/fadump: align destination address to pagesize On crash, boot memory area is copied to a destination address by f/w. This region is setup as separate PT_LOAD segment with appropriate offset to handle the different physical address and offset in vmcore. If this destination address is not page aligned, reading the vmcore with mmap is likely to fail forcing tools like makedumpfile to fall back to regular read. Avoid mmap read failure by ensuring that the destination address is always page aligned. Signed-off-by: Hari Bathini Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220406093839.206608-3-hbathini@linux.ibm.com --- diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c index 044fbf7e4d8a1..4f2bd7952604c 100644 --- a/arch/powerpc/kernel/fadump.c +++ b/arch/powerpc/kernel/fadump.c @@ -365,6 +365,11 @@ static unsigned long __init get_fadump_area_size(void) size += fw_dump.cpu_state_data_size; size += fw_dump.hpte_region_size; + /* + * Account for pagesize alignment of boot memory area destination address. + * This faciliates in mmap reading of first kernel's memory. + */ + size = PAGE_ALIGN(size); size += fw_dump.boot_memory_size; size += sizeof(struct fadump_crash_info_header); size += sizeof(struct elfhdr); /* ELF core header.*/ diff --git a/arch/powerpc/platforms/pseries/rtas-fadump.c b/arch/powerpc/platforms/pseries/rtas-fadump.c index 617c0f3b1f4f1..bc8d1ce20f8f8 100644 --- a/arch/powerpc/platforms/pseries/rtas-fadump.c +++ b/arch/powerpc/platforms/pseries/rtas-fadump.c @@ -108,6 +108,12 @@ static u64 rtas_fadump_init_mem_struct(struct fw_dump *fadump_conf) fdm.hpte_region.destination_address = cpu_to_be64(addr); addr += fadump_conf->hpte_region_size; + /* + * Align boot memory area destination address to page boundary to + * be able to mmap read this area in the vmcore. + */ + addr = PAGE_ALIGN(addr); + /* RMA region section */ fdm.rmr_region.request_flag = cpu_to_be32(RTAS_FADUMP_REQUEST_FLAG); fdm.rmr_region.source_data_type =