diff options
Diffstat (limited to 'arch/powerpc/mm/ptdump/ptdump.c')
-rw-r--r-- | arch/powerpc/mm/ptdump/ptdump.c | 92 |
1 files changed, 75 insertions, 17 deletions
diff --git a/arch/powerpc/mm/ptdump/ptdump.c b/arch/powerpc/mm/ptdump/ptdump.c index 37138428ab55..39bf1e2cba13 100644 --- a/arch/powerpc/mm/ptdump/ptdump.c +++ b/arch/powerpc/mm/ptdump/ptdump.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * Copyright 2016, Rashmica Gupta, IBM Corp. * @@ -8,11 +9,6 @@ * Derived from the arm64 implementation: * Copyright (c) 2014, The Linux Foundation, Laura Abbott. * (C) Copyright 2008 Intel Corporation, Arjan van de Ven. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; version 2 - * of the License. */ #include <linux/debugfs.h> #include <linux/fs.h> @@ -31,7 +27,7 @@ #include "ptdump.h" #ifdef CONFIG_PPC32 -#define KERN_VIRT_START 0 +#define KERN_VIRT_START PAGE_OFFSET #endif /* @@ -68,6 +64,8 @@ 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 +99,25 @@ 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 +135,19 @@ 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 +162,12 @@ 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 */ @@ -161,8 +175,22 @@ 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, @@ -178,7 +206,7 @@ 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 +222,7 @@ 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 +231,7 @@ 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 +240,7 @@ 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 +332,9 @@ 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 +352,10 @@ 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 +400,30 @@ 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; |