[PATCH v2] of/fdt: add dt_phys arg to early_init_dt_scan and early_init_dt_verify

Usama Arif
2024-10-23T17:14:38Z

__pa() is only intended to be used for linear map addresses and using
it for initial_boot_params which is in fixmap for arm64 will give an
incorrect value. Hence save the physical address when it is known at
boot time when calling early_init_dt_scan for arm64 and use it at kexec
time instead of converting the virtual address using __pa().

Reported-by: Breno Leitao <leitao@debian.org>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Usama Arif <usamaarif642@gmail.com>
Fixes: ac10be5cdbfa ("arm64: Use common of_kexec_alloc_and_setup_fdt()")
---
v1 -> 2:
- pass dt_phys in early_init_dt_scan instead of creating
anorther arch->dt function (Rob Herring)
---
arch/arc/kernel/devtree.c | 2 +-
arch/arm/kernel/devtree.c | 2 +-
arch/arm64/kernel/setup.c | 6 +++++-
arch/csky/kernel/setup.c | 4 ++--
arch/loongarch/kernel/setup.c | 2 +-
arch/microblaze/kernel/prom.c | 2 +-
arch/mips/kernel/prom.c | 2 +-
arch/mips/kernel/relocate.c | 2 +-
arch/nios2/kernel/prom.c | 4 ++--
arch/openrisc/kernel/prom.c | 2 +-
arch/powerpc/kernel/dt_cpu_ftrs.c | 2 +-
arch/powerpc/kernel/prom.c | 2 +-
arch/powerpc/platforms/pseries/plpks.c | 2 +-
arch/riscv/kernel/setup.c | 2 +-
arch/sh/kernel/setup.c | 2 +-
arch/um/kernel/dtb.c | 2 +-
arch/x86/kernel/devicetree.c | 2 +-
arch/xtensa/kernel/setup.c | 2 +-
drivers/of/fdt.c | 14 ++++++++------
drivers/of/kexec.c | 2 +-
include/linux/of_fdt.h | 5 +++--
21 files changed, 36 insertions(+), 29 deletions(-)

diff --git a/arch/arc/kernel/devtree.c b/arch/arc/kernel/devtree.c
index 4c9e61457b2f..cc6ac7d128aa 100644
--- a/arch/arc/kernel/devtree.c
+++ b/arch/arc/kernel/devtree.c
@@ -62,7 +62,7 @@ const struct machine_desc * __init setup_machine_fdt(void *dt)
const struct machine_desc *mdesc;
unsigned long dt_root;

- if (!early_init_dt_scan(dt))
+ if (!early_init_dt_scan(dt, __pa(dt)))
return NULL;

mdesc = of_flat_dt_match_machine(NULL, arch_get_next_mach);
diff --git a/arch/arm/kernel/devtree.c b/arch/arm/kernel/devtree.c
index fdb74e64206a..3b78966e750a 100644
--- a/arch/arm/kernel/devtree.c
+++ b/arch/arm/kernel/devtree.c
@@ -200,7 +200,7 @@ const struct machine_desc * __init setup_machine_fdt(void *dt_virt)

mdesc_best = &__mach_desc_GENERIC_DT;

- if (!dt_virt || !early_init_dt_verify(dt_virt))
+ if (!dt_virt || !early_init_dt_verify(dt_virt, __pa(dt_virt)))
return NULL;

mdesc = of_flat_dt_match_machine(mdesc_best, arch_get_next_mach);
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index b22d28ec8028..177262739c49 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -175,7 +175,11 @@ static void __init setup_machine_fdt(phys_addr_t dt_phys)
if (dt_virt)
memblock_reserve(dt_phys, size);

- if (!dt_virt || !early_init_dt_scan(dt_virt)) {
+ /*
+ * dt_virt is a fixmap address, hence __pa(dt_virt) can't be used.
+ * Pass dt_phys directly.
+ */
+ if (!dt_virt || !early_init_dt_scan(dt_virt, dt_phys)) {
pr_crit("\n"
"Error: invalid device tree blob at physical address %pa (virtual address 0x%px)\n"
"The dtb must be 8-byte aligned and must not exceed 2 MB in size\n"
diff --git a/arch/csky/kernel/setup.c b/arch/csky/kernel/setup.c
index 51012e90780d..fe715b707fd0 100644
--- a/arch/csky/kernel/setup.c
+++ b/arch/csky/kernel/setup.c
@@ -112,9 +112,9 @@ asmlinkage __visible void __init csky_start(unsigned int unused,
pre_trap_init();

if (dtb_start == NULL)
- early_init_dt_scan(__dtb_start);
+ early_init_dt_scan(__dtb_start, __pa(dtb_start));
else
- early_init_dt_scan(dtb_start);
+ early_init_dt_scan(dtb_start, __pa(dtb_start));

start_kernel();

diff --git a/arch/loongarch/kernel/setup.c b/arch/loongarch/kernel/setup.c
index 00e307203ddb..10d878204018 100644
--- a/arch/loongarch/kernel/setup.c
+++ b/arch/loongarch/kernel/setup.c
@@ -290,7 +290,7 @@ static void __init fdt_setup(void)
if (!fdt_pointer || fdt_check_header(fdt_pointer))
return;

- early_init_dt_scan(fdt_pointer);
+ early_init_dt_scan(fdt_pointer, __pa(fdt_pointer));
early_init_fdt_reserve_self();

max_low_pfn = PFN_PHYS(memblock_end_of_DRAM());
diff --git a/arch/microblaze/kernel/prom.c b/arch/microblaze/kernel/prom.c
index e424c796e297..76ac4cfdfb42 100644
--- a/arch/microblaze/kernel/prom.c
+++ b/arch/microblaze/kernel/prom.c
@@ -18,7 +18,7 @@ void __init early_init_devtree(void *params)
{
pr_debug(" -> early_init_devtree(%p)\n", params);

- early_init_dt_scan(params);
+ early_init_dt_scan(params, __pa(params));
if (!strlen(boot_command_line))
strscpy(boot_command_line, cmd_line, COMMAND_LINE_SIZE);

diff --git a/arch/mips/kernel/prom.c b/arch/mips/kernel/prom.c
index 6062e6fa589a..4fd6da0a06c3 100644
--- a/arch/mips/kernel/prom.c
+++ b/arch/mips/kernel/prom.c
@@ -41,7 +41,7 @@ char *mips_get_machine_name(void)

void __init __dt_setup_arch(void *bph)
{
- if (!early_init_dt_scan(bph))
+ if (!early_init_dt_scan(bph, __pa(bph)))
return;

mips_set_machine_name(of_flat_dt_get_machine_name());
diff --git a/arch/mips/kernel/relocate.c b/arch/mips/kernel/relocate.c
index 7eeeaf1ff95d..cda7983e7c18 100644
--- a/arch/mips/kernel/relocate.c
+++ b/arch/mips/kernel/relocate.c
@@ -337,7 +337,7 @@ void *__init relocate_kernel(void)
#if defined(CONFIG_USE_OF)
/* Deal with the device tree */
fdt = plat_get_fdt();
- early_init_dt_scan(fdt);
+ early_init_dt_scan(fdt, __pa(fdt));
if (boot_command_line[0]) {
/* Boot command line was passed in device tree */
strscpy(arcs_cmdline, boot_command_line, COMMAND_LINE_SIZE);
diff --git a/arch/nios2/kernel/prom.c b/arch/nios2/kernel/prom.c
index 9a8393e6b4a8..db049249766f 100644
--- a/arch/nios2/kernel/prom.c
+++ b/arch/nios2/kernel/prom.c
@@ -27,7 +27,7 @@ void __init early_init_devtree(void *params)
if (be32_to_cpup((__be32 *)CONFIG_NIOS2_DTB_PHYS_ADDR) ==
OF_DT_HEADER) {
params = (void *)CONFIG_NIOS2_DTB_PHYS_ADDR;
- early_init_dt_scan(params);
+ early_init_dt_scan(params, __pa(params));
return;
}
#endif
@@ -37,5 +37,5 @@ void __init early_init_devtree(void *params)
params = (void *)__dtb_start;
#endif

- early_init_dt_scan(params);
+ early_init_dt_scan(params, __pa(params));
}
diff --git a/arch/openrisc/kernel/prom.c b/arch/openrisc/kernel/prom.c
index 19e6008bf114..e424e9bd12a7 100644
--- a/arch/openrisc/kernel/prom.c
+++ b/arch/openrisc/kernel/prom.c
@@ -22,6 +22,6 @@

void __init early_init_devtree(void *params)
{
- early_init_dt_scan(params);
+ early_init_dt_scan(params, __pa(params));
memblock_allow_resize();
}
diff --git a/arch/powerpc/kernel/dt_cpu_ftrs.c b/arch/powerpc/kernel/dt_cpu_ftrs.c
index af4263594eb2..1bee15c013e7 100644
--- a/arch/powerpc/kernel/dt_cpu_ftrs.c
+++ b/arch/powerpc/kernel/dt_cpu_ftrs.c
@@ -867,7 +867,7 @@ bool __init dt_cpu_ftrs_init(void *fdt)
using_dt_cpu_ftrs = false;

/* Setup and verify the FDT, if it fails we just bail */
- if (!early_init_dt_verify(fdt))
+ if (!early_init_dt_verify(fdt, __pa(fdt)))
return false;

if (!of_scan_flat_dt(fdt_find_cpu_features, NULL))
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 0be07ed407c7..88cbe432cad5 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -791,7 +791,7 @@ void __init early_init_devtree(void *params)
DBG(" -> early_init_devtree(%px)\n", params);

/* Too early to BUG_ON(), do it by hand */
- if (!early_init_dt_verify(params))
+ if (!early_init_dt_verify(params, __pa(params)))
panic("BUG: Failed verifying flat device tree, bad version?");

of_scan_flat_dt(early_init_dt_scan_model, NULL);
diff --git a/arch/powerpc/platforms/pseries/plpks.c b/arch/powerpc/platforms/pseries/plpks.c
index 4a595493d28a..b1667ed05f98 100644
--- a/arch/powerpc/platforms/pseries/plpks.c
+++ b/arch/powerpc/platforms/pseries/plpks.c
@@ -683,7 +683,7 @@ void __init plpks_early_init_devtree(void)
out:
fdt_nop_property(fdt, chosen_node, "ibm,plpks-pw");
// Since we've cleared the password, we must update the FDT checksum
- early_init_dt_verify(fdt);
+ early_init_dt_verify(fdt, __pa(fdt));
}

static __init int pseries_plpks_init(void)
diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index a2cde65b69e9..26c886db4fb3 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -227,7 +227,7 @@ static void __init init_resources(void)
static void __init parse_dtb(void)
{
/* Early scan of device tree from init memory */
- if (early_init_dt_scan(dtb_early_va)) {
+ if (early_init_dt_scan(dtb_early_va, __pa(dtb_early_va))) {
const char *name = of_flat_dt_get_machine_name();

if (name) {
diff --git a/arch/sh/kernel/setup.c b/arch/sh/kernel/setup.c
index 620e5cf8ae1e..f2b6f16a46b8 100644
--- a/arch/sh/kernel/setup.c
+++ b/arch/sh/kernel/setup.c
@@ -255,7 +255,7 @@ void __ref sh_fdt_init(phys_addr_t dt_phys)
dt_virt = phys_to_virt(dt_phys);
#endif

- if (!dt_virt || !early_init_dt_scan(dt_virt)) {
+ if (!dt_virt || !early_init_dt_scan(dt_virt, __pa(dt_virt))) {
pr_crit("Error: invalid device tree blob"
" at physical address %p\n", (void *)dt_phys);

diff --git a/arch/um/kernel/dtb.c b/arch/um/kernel/dtb.c
index 4954188a6a09..8d78ced9e08f 100644
--- a/arch/um/kernel/dtb.c
+++ b/arch/um/kernel/dtb.c
@@ -17,7 +17,7 @@ void uml_dtb_init(void)

area = uml_load_file(dtb, &size);
if (area) {
- if (!early_init_dt_scan(area)) {
+ if (!early_init_dt_scan(area, __pa(area))) {
pr_err("invalid DTB %s\n", dtb);
memblock_free(area, size);
return;
diff --git a/arch/x86/kernel/devicetree.c b/arch/x86/kernel/devicetree.c
index 64280879c68c..59d23cdf4ed0 100644
--- a/arch/x86/kernel/devicetree.c
+++ b/arch/x86/kernel/devicetree.c
@@ -305,7 +305,7 @@ void __init x86_flattree_get_config(void)
map_len = size;
}

- early_init_dt_verify(dt);
+ early_init_dt_verify(dt, __pa(dt));
}

unflatten_and_copy_device_tree();
diff --git a/arch/xtensa/kernel/setup.c b/arch/xtensa/kernel/setup.c
index bdec4a773af0..e51f2060e830 100644
--- a/arch/xtensa/kernel/setup.c
+++ b/arch/xtensa/kernel/setup.c
@@ -216,7 +216,7 @@ static int __init xtensa_dt_io_area(unsigned long node, const char *uname,

void __init early_init_devtree(void *params)
{
- early_init_dt_scan(params);
+ early_init_dt_scan(params, __pa(params));
of_scan_flat_dt(xtensa_dt_io_area, NULL);

if (!command_line[0])
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 4d528c10df3a..546e76ac407c 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -457,6 +457,7 @@ int __initdata dt_root_addr_cells;
int __initdata dt_root_size_cells;

void *initial_boot_params __ro_after_init;
+phys_addr_t initial_boot_params_pa __ro_after_init;

#ifdef CONFIG_OF_EARLY_FLATTREE

@@ -1136,17 +1137,18 @@ static void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
return ptr;
}

-bool __init early_init_dt_verify(void *params)
+bool __init early_init_dt_verify(void *dt_virt, phys_addr_t dt_phys)
{
- if (!params)
+ if (!dt_virt)
return false;

/* check device tree validity */
- if (fdt_check_header(params))
+ if (fdt_check_header(dt_virt))
return false;

/* Setup flat device-tree pointer */
- initial_boot_params = params;
+ initial_boot_params = dt_virt;
+ initial_boot_params_pa = dt_phys;
of_fdt_crc32 = crc32_be(~0, initial_boot_params,
fdt_totalsize(initial_boot_params));

@@ -1173,11 +1175,11 @@ void __init early_init_dt_scan_nodes(void)
early_init_dt_check_for_usable_mem_range();
}

-bool __init early_init_dt_scan(void *params)
+bool __init early_init_dt_scan(void *dt_virt, phys_addr_t dt_phys)
{
bool status;

- status = early_init_dt_verify(params);
+ status = early_init_dt_verify(dt_virt, dt_phys);
if (!status)
return false;

diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
index 9ccde2fd77cb..5b924597a4de 100644
--- a/drivers/of/kexec.c
+++ b/drivers/of/kexec.c
@@ -301,7 +301,7 @@ void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
}

/* Remove memory reservation for the current device tree. */
- ret = fdt_find_and_del_mem_rsv(fdt, __pa(initial_boot_params),
+ ret = fdt_find_and_del_mem_rsv(fdt, initial_boot_params_pa,
fdt_totalsize(initial_boot_params));
if (ret == -EINVAL) {
pr_err("Error removing memory reservation.\n");
diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h
index d69ad5bb1eb1..b8d6c0c20876 100644
--- a/include/linux/of_fdt.h
+++ b/include/linux/of_fdt.h
@@ -31,6 +31,7 @@ extern void *of_fdt_unflatten_tree(const unsigned long *blob,
extern int __initdata dt_root_addr_cells;
extern int __initdata dt_root_size_cells;
extern void *initial_boot_params;
+extern phys_addr_t initial_boot_params_pa;

extern char __dtb_start[];
extern char __dtb_end[];
@@ -70,8 +71,8 @@ extern u64 dt_mem_next_cell(int s, const __be32 **cellp);
/* Early flat tree scan hooks */
extern int early_init_dt_scan_root(void);

-extern bool early_init_dt_scan(void *params);
-extern bool early_init_dt_verify(void *params);
+extern bool early_init_dt_scan(void *dt_virt, phys_addr_t dt_phys);
+extern bool early_init_dt_verify(void *dt_virt, phys_addr_t dt_phys);
extern void early_init_dt_scan_nodes(void);

extern const char *of_flat_dt_get_machine_name(void);
--
2.43.5