[PATCH v2 3/6] arm64: ptdump: fold string literals into address_markers[] and pte_bits[]

Ard Biesheuvel
2016-04-22T16:48:05Z

Replace the indirect string references in struct addr_marker and struct
prot_bits with char array fields. Under a relocatable kernel, this not
only saves 8 bytes in the absolute address that we no longer have to record,
it also saves 24 bytes of init data (the size of a RELA entry) since this
address no longer requires relocation processing at boot.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
I am aware that this is a drop in the ocean, but I thought I'd include it
anyway, since many people may not even realize that this issue exists in
the first place.
---
arch/arm64/mm/dump.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/dump.c
index 8404190fe2bd..024f803e2fb4 100644
--- a/arch/arm64/mm/dump.c
+++ b/arch/arm64/mm/dump.c
@@ -30,7 +30,7 @@

struct addr_marker {
unsigned long start_address;
- const char *name;
+ char name[32];
};

static const struct addr_marker address_markers[] = {
@@ -51,7 +51,7 @@ static const struct addr_marker address_markers[] = {
{ VMEMMAP_START + VMEMMAP_SIZE, "vmemmap end" },
#endif
{ PAGE_OFFSET, "Linear Mapping" },
- { -1, NULL },
+ { -1 },
};

/*
@@ -69,10 +69,10 @@ struct pg_state {
};

struct prot_bits {
- u64 mask;
- u64 val;
- const char *set;
- const char *clear;
+ u64 mask;
+ u64 val;
+ char set[16];
+ char clear[8];
};

static const struct prot_bits pte_bits[] = {
@@ -184,7 +184,7 @@ static void dump_prot(struct pg_state *st, const struct prot_bits *bits,
else
s = bits->clear;

- if (s)
+ if (*s)
seq_printf(st->seq, " %s", s);
}
}
--
2.7.4