[RFC v2][PATCH 07/11] ARM: mm: set DOMAIN_WR_RARE for rodata
From: Kees Cook <hidden>
Date: 2017-03-29 18:18:32
Also in:
lkml
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
This creates DOMAIN_WR_RARE for the kernel's .rodata section, separate from DOMAIN_KERNEL to avoid predictive fetching in device memory during a DOMAIN_MANAGER transition. TODO: handle kernel module vmalloc memory, which needs to be marked as DOMAIN_WR_RARE too, for module .rodata sections. Signed-off-by: Kees Cook <redacted> --- arch/arm/include/asm/domain.h | 3 +++ arch/arm/mm/dump.c | 2 ++ arch/arm/mm/init.c | 7 ++++--- 3 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/arch/arm/include/asm/domain.h b/arch/arm/include/asm/domain.h
index 8b33bd7f6bf9..b5ca80ac823c 100644
--- a/arch/arm/include/asm/domain.h
+++ b/arch/arm/include/asm/domain.h@@ -43,6 +43,7 @@ #define DOMAIN_IO 0 #endif #define DOMAIN_VECTORS 3 +#define DOMAIN_WR_RARE 4 /* * Domain types
@@ -69,11 +70,13 @@ #define DACR_INIT \ (__DACR_INIT_USER | \ domain_val(DOMAIN_KERNEL, DOMAIN_MANAGER) | \ + domain_val(DOMAIN_WR_RARE, DOMAIN_CLIENT) | \ domain_val(DOMAIN_IO, DOMAIN_CLIENT) | \ domain_val(DOMAIN_VECTORS, DOMAIN_CLIENT)) #define __DACR_DEFAULT \ domain_val(DOMAIN_KERNEL, DOMAIN_CLIENT) | \ + domain_val(DOMAIN_WR_RARE, DOMAIN_CLIENT) | \ domain_val(DOMAIN_IO, DOMAIN_CLIENT) | \ domain_val(DOMAIN_VECTORS, DOMAIN_CLIENT)
diff --git a/arch/arm/mm/dump.c b/arch/arm/mm/dump.c
index 35ff45470dbf..b1aa9a17e0c3 100644
--- a/arch/arm/mm/dump.c
+++ b/arch/arm/mm/dump.c@@ -288,6 +288,8 @@ static const char *get_domain_name(pmd_t *pmd) return "IO "; case PMD_DOMAIN(DOMAIN_VECTORS): return "VECTORS"; + case PMD_DOMAIN(DOMAIN_WR_RARE): + return "WR_RARE"; default: return "unknown"; }
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 1d8558ff9827..d54a74b5718b 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c@@ -642,9 +642,10 @@ static struct section_perm ro_perms[] = { .mask = ~L_PMD_SECT_RDONLY, .prot = L_PMD_SECT_RDONLY, #else - .mask = ~(PMD_SECT_APX | PMD_SECT_AP_WRITE), - .prot = PMD_SECT_APX | PMD_SECT_AP_WRITE, - .clear = PMD_SECT_AP_WRITE, + .mask = ~(PMD_SECT_APX | PMD_SECT_AP_WRITE | PMD_DOMAIN_MASK), + .prot = PMD_SECT_APX | PMD_SECT_AP_WRITE | \ + PMD_DOMAIN(DOMAIN_WR_RARE), + .clear = PMD_SECT_AP_WRITE | PMD_DOMAIN(DOMAIN_KERNEL), #endif }, };
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2.7.4