From 9cf3b3a33a36ef4a988be0a770edd3555297f2a9 Mon Sep 17 00:00:00 2001
From: Hari Bathini <hbathini@linux.ibm.com>
Date: Wed, 6 Apr 2022 15:08:38 +0530
Subject: [PATCH] powerpc/fadump: align destination address to pagesize
References: bsc#1204728 ltc#200074
Patch-mainline: v5.19-rc1
Git-commit: 9cf3b3a33a36ef4a988be0a770edd3555297f2a9
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 <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220406093839.206608-3-hbathini@linux.ibm.com
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
arch/powerpc/kernel/fadump.c | 5 +++++
arch/powerpc/platforms/pseries/rtas-fadump.c | 6 ++++++
2 files changed, 11 insertions(+)
diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index 044fbf7e4d8a..4f2bd7952604 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 617c0f3b1f4f..bc8d1ce20f8f 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 =
--
2.35.3