Re: [PATCH] powerpc/fadump: reset dump area size variable if memblock reserve fails

[Sourabh Jain]

On 03/07/23 16:59, Michael Ellerman wrote:
Sourabh Jain <sourabhj...@linux.ibm.com> writes:
Hello Michael,

Do you have any feedback or comments regarding this patch?

Thanks,
Sourabh

On 08/06/23 14:52, Sourabh Jain wrote:
If the memory reservation process (memblock_reserve) fails to reserve
the memory, the reserve dump variable retains the dump area size.
Consequently, the size of the dump area calculated for reservation
is displayed in /sys/kernel/fadump/mem_reserved.

To resolve this issue, the reserve dump area size variable is set to 0
if the memblock_reserve fails to reserve memory.

Fixes: 8255da95e545 ("powerpc/fadump: release all the memory above boot memory 
size")
Signed-off-by: Sourabh Jain <sourabhj...@linux.ibm.com>
Acked-by: Mahesh Salgaonkar <mah...@linux.ibm.com>
---
   arch/powerpc/kernel/fadump.c | 1 +
   1 file changed, 1 insertion(+)

diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index ea0a073abd96..a8f2c3b2fa1e 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -641,6 +641,7 @@ int __init fadump_reserve_mem(void)
                        goto error_out;
   
   		if (memblock_reserve(base, size)) {
+                       fw_dump.reserve_dump_area_size = 0;
                        pr_err("Failed to reserve memory!\n");
                        goto error_out;
                }
Shouldn't reserve_dump_area_size be set to zero at error_out, which
already clears fadump_enabled?

        return ret;
error_out:
        fw_dump.fadump_enabled = 0;
        return 0;
}


Otherwise the code immediately above will suffer from the same issue
won't it?

                if (fw_dump.ops->fadump_setup_metadata &&
                    (fw_dump.ops->fadump_setup_metadata(&fw_dump) < 0))
                        goto error_out;

Agree, resetting fw_dump.reserve_dump_area_size below error_out label is 
better.

Thanks for the review. I will send v2.

Sourabh Jain