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Date: Thu, 2 Mar 2017 16:30:33 -0800
From: Kees Cook <keescook@...omium.org>
To: Russell King <linux@...linux.org.uk>
Cc: Mark Rutland <mark.rutland@....com>,
Afzal Mohammed <afzal.mohd.ma@...il.com>,
linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
kernel-hardening@...ts.openwall.com
Subject: [PATCH v2] ARM: ptdump: Add domain to output
This adds the memory domain (on non-LPAE) to the PMD and PTE dumps. This
isn't in the regular PMD bit struct because I couldn't find a clean way to
fall back to retain some of the PMD bits when reporting PTE. So this is
special-cased for now.
New output example:
---[ Modules ]---
0x7f000000-0x7f001000 4K DOMAIN_KERNEL ro x SHD MEM/CACHED/WBWA
0x7f001000-0x7f002000 4K DOMAIN_KERNEL ro NX SHD MEM/CACHED/WBWA
0x7f002000-0x7f004000 8K DOMAIN_KERNEL RW NX SHD MEM/CACHED/WBWA
---[ Kernel Mapping ]---
0x80000000-0x80100000 1M DOMAIN_KERNEL RW NX SHD
0x80100000-0x80800000 7M DOMAIN_KERNEL ro x SHD
0x80800000-0x80b00000 3M DOMAIN_KERNEL ro NX SHD
0x80b00000-0xa0000000 501M DOMAIN_KERNEL RW NX SHD
...
---[ Vectors ]---
0xffff0000-0xffff1000 4K DOMAIN_VECTORS USR ro x SHD MEM/CACHED/WBWA
0xffff1000-0xffff2000 4K DOMAIN_VECTORS ro x SHD MEM/CACHED/WBWA
Signed-off-by: Kees Cook <keescook@...omium.org>
---
This actually works correctly now (tested by forcing different domains on
portions of the Kernel Mapping. I really wanted to find a way to use the
existing bit structs, but I couldn't make anything work... I'm open to ideas.
---
arch/arm/mm/dump.c | 54 ++++++++++++++++++++++++++++++++++++++++++++----------
1 file changed, 44 insertions(+), 10 deletions(-)
diff --git a/arch/arm/mm/dump.c b/arch/arm/mm/dump.c
index 21192d6eda40..3770d9f83bdc 100644
--- a/arch/arm/mm/dump.c
+++ b/arch/arm/mm/dump.c
@@ -17,6 +17,7 @@
#include <linux/mm.h>
#include <linux/seq_file.h>
+#include <asm/domain.h>
#include <asm/fixmap.h>
#include <asm/memory.h>
#include <asm/pgtable.h>
@@ -43,6 +44,7 @@ struct pg_state {
unsigned long start_address;
unsigned level;
u64 current_prot;
+ const char *current_domain;
};
struct prot_bits {
@@ -216,7 +218,8 @@ static void dump_prot(struct pg_state *st, const struct prot_bits *bits, size_t
}
}
-static void note_page(struct pg_state *st, unsigned long addr, unsigned level, u64 val)
+static void note_page(struct pg_state *st, unsigned long addr, unsigned level,
+ u64 val, const char *domain)
{
static const char units[] = "KMGTPE";
u64 prot = val & pg_level[level].mask;
@@ -224,8 +227,10 @@ static void note_page(struct pg_state *st, unsigned long addr, unsigned level, u
if (!st->level) {
st->level = level;
st->current_prot = prot;
+ st->current_domain = domain;
seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
} else if (prot != st->current_prot || level != st->level ||
+ domain != st->current_domain ||
addr >= st->marker[1].start_address) {
const char *unit = units;
unsigned long delta;
@@ -240,6 +245,8 @@ static void note_page(struct pg_state *st, unsigned long addr, unsigned level, u
unit++;
}
seq_printf(st->seq, "%9lu%c", delta, *unit);
+ if (st->current_domain)
+ seq_printf(st->seq, " %s", st->current_domain);
if (pg_level[st->level].bits)
dump_prot(st, pg_level[st->level].bits, pg_level[st->level].num);
seq_printf(st->seq, "\n");
@@ -251,11 +258,13 @@ static void note_page(struct pg_state *st, unsigned long addr, unsigned level, u
}
st->start_address = addr;
st->current_prot = prot;
+ st->current_domain = domain;
st->level = level;
}
}
-static void walk_pte(struct pg_state *st, pmd_t *pmd, unsigned long start)
+static void walk_pte(struct pg_state *st, pmd_t *pmd, unsigned long start,
+ const char *domain)
{
pte_t *pte = pte_offset_kernel(pmd, 0);
unsigned long addr;
@@ -263,25 +272,50 @@ static void walk_pte(struct pg_state *st, pmd_t *pmd, unsigned long start)
for (i = 0; i < PTRS_PER_PTE; i++, pte++) {
addr = start + i * PAGE_SIZE;
- note_page(st, addr, 4, pte_val(*pte));
+ note_page(st, addr, 4, pte_val(*pte), domain);
}
}
+static const char *get_domain_name(pmd_t *pmd)
+{
+#ifndef CONFIG_ARM_LPAE
+ switch (pmd_val(*pmd) & PMD_DOMAIN_MASK) {
+ case PMD_DOMAIN(DOMAIN_KERNEL):
+ return "DOMAIN_KERNEL ";
+ case PMD_DOMAIN(DOMAIN_USER):
+ return "DOMAIN_USER ";
+ case PMD_DOMAIN(DOMAIN_IO):
+ return "DOMAIN_IO ";
+ case PMD_DOMAIN(DOMAIN_VECTORS):
+ return "DOMAIN_VECTORS";
+ default:
+ return "DOMAIN_unknown";
+ }
+#endif
+ return NULL;
+}
+
static void walk_pmd(struct pg_state *st, pud_t *pud, unsigned long start)
{
pmd_t *pmd = pmd_offset(pud, 0);
unsigned long addr;
unsigned i;
+ const char *domain;
for (i = 0; i < PTRS_PER_PMD; i++, pmd++) {
addr = start + i * PMD_SIZE;
+ domain = get_domain_name(pmd);
if (pmd_none(*pmd) || pmd_large(*pmd) || !pmd_present(*pmd))
- note_page(st, addr, 3, pmd_val(*pmd));
+ note_page(st, addr, 3, pmd_val(*pmd), domain);
else
- walk_pte(st, pmd, addr);
+ walk_pte(st, pmd, addr, domain);
- if (SECTION_SIZE < PMD_SIZE && pmd_large(pmd[1]))
- note_page(st, addr + SECTION_SIZE, 3, pmd_val(pmd[1]));
+ if (SECTION_SIZE < PMD_SIZE && pmd_large(pmd[1])) {
+ addr += SECTION_SIZE;
+ pmd++;
+ domain = get_domain_name(pmd);
+ note_page(st, addr, 3, pmd_val(*pmd), domain);
+ }
}
}
@@ -296,7 +330,7 @@ static void walk_pud(struct pg_state *st, pgd_t *pgd, unsigned long start)
if (!pud_none(*pud)) {
walk_pmd(st, pud, addr);
} else {
- note_page(st, addr, 2, pud_val(*pud));
+ note_page(st, addr, 2, pud_val(*pud), NULL);
}
}
}
@@ -317,11 +351,11 @@ static void walk_pgd(struct seq_file *m)
if (!pgd_none(*pgd)) {
walk_pud(&st, pgd, addr);
} else {
- note_page(&st, addr, 1, pgd_val(*pgd));
+ note_page(&st, addr, 1, pgd_val(*pgd), NULL);
}
}
- note_page(&st, 0, 0, 0);
+ note_page(&st, 0, 0, 0, NULL);
}
static int ptdump_show(struct seq_file *m, void *v)
--
2.7.4
--
Kees Cook
Pixel Security
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