Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'riscv-for-linus-6.4-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V fixes from Palmer Dabbelt:
- A fix to avoid ISA-disallowed privilege mappings that can result from
WRITE+EXEC mmap requests from userspace.
- A fix for kfence to handle the huge pages.
- A fix to avoid converting misaligned VAs to huge pages.
- ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE has been selected so kprobe
can understand user pointers.
* tag 'riscv-for-linus-6.4-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
riscv: fix kprobe __user string arg print fault issue
riscv: Check the virtual alignment before choosing a map size
riscv: Fix kfence now that the linear mapping can be backed by PUD/P4D/PGD
riscv: mm: Ensure prot of VM_WRITE and VM_EXEC must be readable
+39
-46
+1
arch/riscv/Kconfig
+1
arch/riscv/Kconfig
-33
arch/riscv/include/asm/kfence.h
-33
arch/riscv/include/asm/kfence.h
···
8
8
#include <asm-generic/pgalloc.h>
9
9
#include <asm/pgtable.h>
10
10
11
-
static inline int split_pmd_page(unsigned long addr)
12
-
{
13
-
int i;
14
-
unsigned long pfn = PFN_DOWN(__pa((addr & PMD_MASK)));
15
-
pmd_t *pmd = pmd_off_k(addr);
16
-
pte_t *pte = pte_alloc_one_kernel(&init_mm);
17
-
18
-
if (!pte)
19
-
return -ENOMEM;
20
-
21
-
for (i = 0; i < PTRS_PER_PTE; i++)
22
-
set_pte(pte + i, pfn_pte(pfn + i, PAGE_KERNEL));
23
-
set_pmd(pmd, pfn_pmd(PFN_DOWN(__pa(pte)), PAGE_TABLE));
24
-
25
-
flush_tlb_kernel_range(addr, addr + PMD_SIZE);
26
-
return 0;
27
-
}
28
-
29
11
static inline bool arch_kfence_init_pool(void)
30
12
{
31
-
int ret;
32
-
unsigned long addr;
33
-
pmd_t *pmd;
34
-
35
-
for (addr = (unsigned long)__kfence_pool; is_kfence_address((void *)addr);
36
-
addr += PAGE_SIZE) {
37
-
pmd = pmd_off_k(addr);
38
-
39
-
if (pmd_leaf(*pmd)) {
40
-
ret = split_pmd_page(addr);
41
-
if (ret)
42
-
return false;
43
-
}
44
-
}
45
-
46
13
return true;
47
14
}
48
15
+1
-2
arch/riscv/include/asm/pgtable.h
+1
-2
arch/riscv/include/asm/pgtable.h
···
165
165
_PAGE_EXEC | _PAGE_WRITE)
166
166
167
167
#define PAGE_COPY PAGE_READ
168
-
#define PAGE_COPY_EXEC PAGE_EXEC
169
-
#define PAGE_COPY_READ_EXEC PAGE_READ_EXEC
168
+
#define PAGE_COPY_EXEC PAGE_READ_EXEC
170
169
#define PAGE_SHARED PAGE_WRITE
171
170
#define PAGE_SHARED_EXEC PAGE_WRITE_EXEC
172
171
+37
-11
arch/riscv/mm/init.c
+37
-11
arch/riscv/mm/init.c
···
23
23
#ifdef CONFIG_RELOCATABLE
24
24
#include <linux/elf.h>
25
25
#endif
26
+
#include <linux/kfence.h>
26
27
27
28
#include <asm/fixmap.h>
28
29
#include <asm/tlbflush.h>
···
294
293
[VM_EXEC] = PAGE_EXEC,
295
294
[VM_EXEC | VM_READ] = PAGE_READ_EXEC,
296
295
[VM_EXEC | VM_WRITE] = PAGE_COPY_EXEC,
297
-
[VM_EXEC | VM_WRITE | VM_READ] = PAGE_COPY_READ_EXEC,
296
+
[VM_EXEC | VM_WRITE | VM_READ] = PAGE_COPY_EXEC,
298
297
[VM_SHARED] = PAGE_NONE,
299
298
[VM_SHARED | VM_READ] = PAGE_READ,
300
299
[VM_SHARED | VM_WRITE] = PAGE_SHARED,
···
660
659
create_pgd_next_mapping(nextp, va, pa, sz, prot);
661
660
}
662
661
663
-
static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size)
662
+
static uintptr_t __init best_map_size(phys_addr_t pa, uintptr_t va,
663
+
phys_addr_t size)
664
664
{
665
-
if (!(base & (PGDIR_SIZE - 1)) && size >= PGDIR_SIZE)
665
+
if (!(pa & (PGDIR_SIZE - 1)) && !(va & (PGDIR_SIZE - 1)) && size >= PGDIR_SIZE)
666
666
return PGDIR_SIZE;
667
667
668
-
if (!(base & (P4D_SIZE - 1)) && size >= P4D_SIZE)
668
+
if (!(pa & (P4D_SIZE - 1)) && !(va & (P4D_SIZE - 1)) && size >= P4D_SIZE)
669
669
return P4D_SIZE;
670
670
671
-
if (!(base & (PUD_SIZE - 1)) && size >= PUD_SIZE)
671
+
if (!(pa & (PUD_SIZE - 1)) && !(va & (PUD_SIZE - 1)) && size >= PUD_SIZE)
672
672
return PUD_SIZE;
673
673
674
-
if (!(base & (PMD_SIZE - 1)) && size >= PMD_SIZE)
674
+
if (!(pa & (PMD_SIZE - 1)) && !(va & (PMD_SIZE - 1)) && size >= PMD_SIZE)
675
675
return PMD_SIZE;
676
676
677
677
return PAGE_SIZE;
···
1169
1167
}
1170
1168
1171
1169
static void __init create_linear_mapping_range(phys_addr_t start,
1172
-
phys_addr_t end)
1170
+
phys_addr_t end,
1171
+
uintptr_t fixed_map_size)
1173
1172
{
1174
1173
phys_addr_t pa;
1175
1174
uintptr_t va, map_size;
1176
1175
1177
1176
for (pa = start; pa < end; pa += map_size) {
1178
1177
va = (uintptr_t)__va(pa);
1179
-
map_size = best_map_size(pa, end - pa);
1178
+
map_size = fixed_map_size ? fixed_map_size :
1179
+
best_map_size(pa, va, end - pa);
1180
1180
1181
1181
create_pgd_mapping(swapper_pg_dir, va, pa, map_size,
1182
1182
pgprot_from_va(va));
···
1188
1184
static void __init create_linear_mapping_page_table(void)
1189
1185
{
1190
1186
phys_addr_t start, end;
1187
+
phys_addr_t kfence_pool __maybe_unused;
1191
1188
u64 i;
1192
1189
1193
1190
#ifdef CONFIG_STRICT_KERNEL_RWX
···
1202
1197
memblock_mark_nomap(krodata_start, krodata_size);
1203
1198
#endif
1204
1199
1200
+
#ifdef CONFIG_KFENCE
1201
+
/*
1202
+
* kfence pool must be backed by PAGE_SIZE mappings, so allocate it
1203
+
* before we setup the linear mapping so that we avoid using hugepages
1204
+
* for this region.
1205
+
*/
1206
+
kfence_pool = memblock_phys_alloc(KFENCE_POOL_SIZE, PAGE_SIZE);
1207
+
BUG_ON(!kfence_pool);
1208
+
1209
+
memblock_mark_nomap(kfence_pool, KFENCE_POOL_SIZE);
1210
+
__kfence_pool = __va(kfence_pool);
1211
+
#endif
1212
+
1205
1213
/* Map all memory banks in the linear mapping */
1206
1214
for_each_mem_range(i, &start, &end) {
1207
1215
if (start >= end)
···
1225
1207
if (end >= __pa(PAGE_OFFSET) + memory_limit)
1226
1208
end = __pa(PAGE_OFFSET) + memory_limit;
1227
1209
1228
-
create_linear_mapping_range(start, end);
1210
+
create_linear_mapping_range(start, end, 0);
1229
1211
}
1230
1212
1231
1213
#ifdef CONFIG_STRICT_KERNEL_RWX
1232
-
create_linear_mapping_range(ktext_start, ktext_start + ktext_size);
1214
+
create_linear_mapping_range(ktext_start, ktext_start + ktext_size, 0);
1233
1215
create_linear_mapping_range(krodata_start,
1234
-
krodata_start + krodata_size);
1216
+
krodata_start + krodata_size, 0);
1235
1217
1236
1218
memblock_clear_nomap(ktext_start, ktext_size);
1237
1219
memblock_clear_nomap(krodata_start, krodata_size);
1220
+
#endif
1221
+
1222
+
#ifdef CONFIG_KFENCE
1223
+
create_linear_mapping_range(kfence_pool,
1224
+
kfence_pool + KFENCE_POOL_SIZE,
1225
+
PAGE_SIZE);
1226
+
1227
+
memblock_clear_nomap(kfence_pool, KFENCE_POOL_SIZE);
1238
1228
#endif
1239
1229
}
1240
1230