From 7082f8e7d2276575a8806370007cbb4a7b9abdce Mon Sep 17 00:00:00 2001
From: Nicholas Piggin <npiggin@gmail.com>
Date: Fri, 16 Sep 2022 14:07:49 +1000
Subject: [PATCH] powerpc: move __end_rodata to cover arch read-only sections
References: bsc#1194869
Patch-mainline: v6.1-rc1
Git-commit: 7082f8e7d2276575a8806370007cbb4a7b9abdce
powerpc has a number of read-only sections and tables that are put after
RO_DATA(). Move the __end_rodata symbol to cover these as well.
Setting memory to read-only at boot is done using __init_begin, change
that to use __end_rodata.
This makes is_kernel_rodata() exactly cover the read-only region, as
well as other things using __end_rodata (e.g., kernel/dma/debug.c).
Boot dmesg also prints the rodata size more accurately.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916040755.2398112-2-npiggin@gmail.com
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
arch/powerpc/kernel/vmlinux.lds.S | 1 +
arch/powerpc/mm/book3s32/mmu.c | 2 +-
arch/powerpc/mm/book3s64/hash_pgtable.c | 2 +-
arch/powerpc/mm/book3s64/radix_pgtable.c | 2 +-
arch/powerpc/mm/pgtable_32.c | 7 ++++---
5 files changed, 8 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 29d891329856..5fe33a659029 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -219,6 +219,7 @@ SECTIONS
*/
. = ALIGN(STRICT_ALIGN_SIZE);
__srwx_boundary = .;
+ __end_rodata = .;
__init_begin = .;
/*
diff --git a/arch/powerpc/mm/book3s32/mmu.c b/arch/powerpc/mm/book3s32/mmu.c
index 250d174459d4..e5ee05c234c7 100644
--- a/arch/powerpc/mm/book3s32/mmu.c
+++ b/arch/powerpc/mm/book3s32/mmu.c
@@ -240,7 +240,7 @@ void mmu_mark_rodata_ro(void)
for (i = 0; i < nb; i++) {
struct ppc_bat *bat = BATS[i];
- if (bat_addrs[i].start < (unsigned long)__init_begin)
+ if (bat_addrs[i].start < (unsigned long)__end_rodata)
bat[1].batl = (bat[1].batl & ~BPP_RW) | BPP_RX;
}
diff --git a/arch/powerpc/mm/book3s64/hash_pgtable.c b/arch/powerpc/mm/book3s64/hash_pgtable.c
index ae008b9df0e6..28332001bd87 100644
--- a/arch/powerpc/mm/book3s64/hash_pgtable.c
+++ b/arch/powerpc/mm/book3s64/hash_pgtable.c
@@ -541,7 +541,7 @@ void hash__mark_rodata_ro(void)
unsigned long start, end, pp;
start = (unsigned long)_stext;
- end = (unsigned long)__init_begin;
+ end = (unsigned long)__end_rodata;
pp = htab_convert_pte_flags(pgprot_val(PAGE_KERNEL_ROX), HPTE_USE_KERNEL_KEY);
diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c
index 9f880f91f584..60c277a9b043 100644
--- a/arch/powerpc/mm/book3s64/radix_pgtable.c
+++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
@@ -228,7 +228,7 @@ void radix__mark_rodata_ro(void)
unsigned long start, end;
start = (unsigned long)_stext;
- end = (unsigned long)__init_begin;
+ end = (unsigned long)__end_rodata;
radix__change_memory_range(start, end, _PAGE_WRITE);
}