Re: [PATCH 02/14] MIPS: memblock: Surely map BSS kernel memory section

From: Matt Redfearn
Date: Mon Jan 22 2018 - 11:38:08 EST


Hi Serge,

On 17/01/18 22:23, Serge Semin wrote:
The current MIPS code makes sure the kernel code/data/init
sections are in the maps, but BSS should also be there.

Quite right - it should. But this was protected against by reserving all bootmem up to the _end symbol here:
http://elixir.free-electrons.com/linux/v4.15-rc8/source/arch/mips/kernel/setup.c#L388
Which you remove in the next patch in this series. I'm not sure it is worth disentangling the reserved_end stuff from the next patch to make this into a single logical change of reserving just .bss rather than everything below _end.

Reviewed-by: Matt Redfearn <matt.redfearn@xxxxxxxx>

Thanks,
Matt


Signed-off-by: Serge Semin <fancer.lancer@xxxxxxxxx>
---
arch/mips/kernel/setup.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index 76e9e2075..0d21c9e04 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -845,6 +845,9 @@ static void __init arch_mem_init(char **cmdline_p)
arch_mem_addpart(PFN_UP(__pa_symbol(&__init_begin)) << PAGE_SHIFT,
PFN_DOWN(__pa_symbol(&__init_end)) << PAGE_SHIFT,
BOOT_MEM_INIT_RAM);
+ arch_mem_addpart(PFN_DOWN(__pa_symbol(&__bss_start)) << PAGE_SHIFT,
+ PFN_UP(__pa_symbol(&__bss_stop)) << PAGE_SHIFT,
+ BOOT_MEM_RAM);
pr_info("Determined physical RAM map:\n");
print_memory_map();