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Diffstat (limited to 'arch/powerpc/mm/ptdump/ptdump.c')
-rw-r--r--arch/powerpc/mm/ptdump/ptdump.c86
1 files changed, 74 insertions, 12 deletions
diff --git a/arch/powerpc/mm/ptdump/ptdump.c b/arch/powerpc/mm/ptdump/ptdump.c
index 37138428ab55..646876d9da64 100644
--- a/arch/powerpc/mm/ptdump/ptdump.c
+++ b/arch/powerpc/mm/ptdump/ptdump.c
@@ -31,7 +31,7 @@
#include "ptdump.h"
#ifdef CONFIG_PPC32
-#define KERN_VIRT_START 0
+#define KERN_VIRT_START PAGE_OFFSET
#endif
/*
@@ -68,6 +68,8 @@ struct pg_state {
unsigned long last_pa;
unsigned int level;
u64 current_flags;
+ bool check_wx;
+ unsigned long wx_pages;
};
struct addr_marker {
@@ -101,9 +103,25 @@ static struct addr_marker address_markers[] = {
{ 0, "Fixmap start" },
{ 0, "Fixmap end" },
#endif
+#ifdef CONFIG_KASAN
+ { 0, "kasan shadow mem start" },
+ { 0, "kasan shadow mem end" },
+#endif
{ -1, NULL },
};
+#define pt_dump_seq_printf(m, fmt, args...) \
+({ \
+ if (m) \
+ seq_printf(m, fmt, ##args); \
+})
+
+#define pt_dump_seq_putc(m, c) \
+({ \
+ if (m) \
+ seq_putc(m, c); \
+})
+
static void dump_flag_info(struct pg_state *st, const struct flag_info
*flag, u64 pte, int num)
{
@@ -121,19 +139,19 @@ static void dump_flag_info(struct pg_state *st, const struct flag_info
val = pte & flag->val;
if (flag->shift)
val = val >> flag->shift;
- seq_printf(st->seq, " %s:%llx", flag->set, val);
+ pt_dump_seq_printf(st->seq, " %s:%llx", flag->set, val);
} else {
if ((pte & flag->mask) == flag->val)
s = flag->set;
else
s = flag->clear;
if (s)
- seq_printf(st->seq, " %s", s);
+ pt_dump_seq_printf(st->seq, " %s", s);
}
st->current_flags &= ~flag->mask;
}
if (st->current_flags != 0)
- seq_printf(st->seq, " unknown flags:%llx", st->current_flags);
+ pt_dump_seq_printf(st->seq, " unknown flags:%llx", st->current_flags);
}
static void dump_addr(struct pg_state *st, unsigned long addr)
@@ -148,12 +166,12 @@ static void dump_addr(struct pg_state *st, unsigned long addr)
#define REG "0x%08lx"
#endif
- seq_printf(st->seq, REG "-" REG " ", st->start_address, addr - 1);
+ pt_dump_seq_printf(st->seq, REG "-" REG " ", st->start_address, addr - 1);
if (st->start_pa == st->last_pa && st->start_address + PAGE_SIZE != addr) {
- seq_printf(st->seq, "[" REG "]", st->start_pa);
+ pt_dump_seq_printf(st->seq, "[" REG "]", st->start_pa);
delta = PAGE_SIZE >> 10;
} else {
- seq_printf(st->seq, " " REG " ", st->start_pa);
+ pt_dump_seq_printf(st->seq, " " REG " ", st->start_pa);
delta = (addr - st->start_address) >> 10;
}
/* Work out what appropriate unit to use */
@@ -161,10 +179,24 @@ static void dump_addr(struct pg_state *st, unsigned long addr)
delta >>= 10;
unit++;
}
- seq_printf(st->seq, "%9lu%c", delta, *unit);
+ pt_dump_seq_printf(st->seq, "%9lu%c", delta, *unit);
}
+static void note_prot_wx(struct pg_state *st, unsigned long addr)
+{
+ if (!st->check_wx)
+ return;
+
+ if (!((st->current_flags & pgprot_val(PAGE_KERNEL_X)) == pgprot_val(PAGE_KERNEL_X)))
+ return;
+
+ WARN_ONCE(1, "powerpc/mm: Found insecure W+X mapping at address %p/%pS\n",
+ (void *)st->start_address, (void *)st->start_address);
+
+ st->wx_pages += (addr - st->start_address) / PAGE_SIZE;
+}
+
static void note_page(struct pg_state *st, unsigned long addr,
unsigned int level, u64 val)
{
@@ -178,7 +210,7 @@ static void note_page(struct pg_state *st, unsigned long addr,
st->start_address = addr;
st->start_pa = pa;
st->last_pa = pa;
- seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
+ pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
/*
* Dump the section of virtual memory when:
* - the PTE flags from one entry to the next differs.
@@ -194,6 +226,7 @@ static void note_page(struct pg_state *st, unsigned long addr,
/* Check the PTE flags */
if (st->current_flags) {
+ note_prot_wx(st, addr);
dump_addr(st, addr);
/* Dump all the flags */
@@ -202,7 +235,7 @@ static void note_page(struct pg_state *st, unsigned long addr,
st->current_flags,
pg_level[st->level].num);
- seq_putc(st->seq, '\n');
+ pt_dump_seq_putc(st->seq, '\n');
}
/*
@@ -211,7 +244,7 @@ static void note_page(struct pg_state *st, unsigned long addr,
*/
while (addr >= st->marker[1].start_address) {
st->marker++;
- seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
+ pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
}
st->start_address = addr;
st->start_pa = pa;
@@ -303,8 +336,9 @@ static void populate_markers(void)
address_markers[i++].start_address = PHB_IO_END;
address_markers[i++].start_address = IOREMAP_BASE;
address_markers[i++].start_address = IOREMAP_END;
+ /* What is the ifdef about? */
#ifdef CONFIG_PPC_BOOK3S_64
- address_markers[i++].start_address = H_VMEMMAP_BASE;
+ address_markers[i++].start_address = H_VMEMMAP_START;
#else
address_markers[i++].start_address = VMEMMAP_BASE;
#endif
@@ -322,6 +356,10 @@ static void populate_markers(void)
#endif
address_markers[i++].start_address = FIXADDR_START;
address_markers[i++].start_address = FIXADDR_TOP;
+#ifdef CONFIG_KASAN
+ address_markers[i++].start_address = KASAN_SHADOW_START;
+ address_markers[i++].start_address = KASAN_SHADOW_END;
+#endif
#endif /* CONFIG_PPC64 */
}
@@ -366,6 +404,30 @@ static void build_pgtable_complete_mask(void)
pg_level[i].mask |= pg_level[i].flag[j].mask;
}
+#ifdef CONFIG_PPC_DEBUG_WX
+void ptdump_check_wx(void)
+{
+ struct pg_state st = {
+ .seq = NULL,
+ .marker = address_markers,
+ .check_wx = true,
+ };
+
+ if (radix_enabled())
+ st.start_address = PAGE_OFFSET;
+ else
+ st.start_address = KERN_VIRT_START;
+
+ walk_pagetables(&st);
+
+ if (st.wx_pages)
+ pr_warn("Checked W+X mappings: FAILED, %lu W+X pages found\n",
+ st.wx_pages);
+ else
+ pr_info("Checked W+X mappings: passed, no W+X pages found\n");
+}
+#endif
+
static int ptdump_init(void)
{
struct dentry *debugfs_file;
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.