| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20260112142009.1006236-14-herve.codina@bootlin.com>
Date: Mon, 12 Jan 2026 15:19:03 +0100
From: Herve Codina <herve.codina@...tlin.com>
To: David Gibson <david@...son.dropbear.id.au>,
Rob Herring <robh@...nel.org>,
Krzysztof Kozlowski <krzk@...nel.org>,
Conor Dooley <conor+dt@...nel.org>
Cc: Ayush Singh <ayush@...gleboard.org>,
Geert Uytterhoeven <geert@...ux-m68k.org>,
devicetree-compiler@...r.kernel.org,
devicetree@...r.kernel.org,
linux-kernel@...r.kernel.org,
devicetree-spec@...r.kernel.org,
Hui Pu <hui.pu@...ealthcare.com>,
Ian Ray <ian.ray@...ealthcare.com>,
Luca Ceresoli <luca.ceresoli@...tlin.com>,
Thomas Petazzoni <thomas.petazzoni@...tlin.com>,
Herve Codina <herve.codina@...tlin.com>
Subject: [RFC PATCH 13/77] Introduce dt_flags field in dtb header
There is no simple way to identify a kind of dtb.
A dtb can be a "standard" device-tree blob but with the future support
for addon dtb, a dtb could be an addon dtb.
Whereas, looking at node structures and name, we can identify if a
"standard" dtb is a pure base device-tree or an overlay device-tree,
this will be no more possible with addons. Indeed, specific node such as
__local_fixups__ and/or __fixups__ present in overlays will be no more
present in addons.
In order to avoid any complex and error prone searches in the dtb
structure to identify whether or not a dtb is an addon, encode this
information directly in the dtb itself.
This is the purpose of the dt_flags field.
Prepare the support for 'addon' flag introducing the dt_flags field
in the dtb header.
Signed-off-by: Herve Codina <herve.codina@...tlin.com>
---
fdtdump.c | 4 ++++
flattree.c | 17 +++++++++++++----
libfdt/fdt.h | 5 ++++-
libfdt/fdt_rw.c | 4 ++++
libfdt/libfdt.h | 1 +
tests/pylibfdt_tests.py | 6 +++---
tests/testutils.c | 2 +-
tests/trees.S | 1 +
8 files changed, 31 insertions(+), 9 deletions(-)
diff --git a/fdtdump.c b/fdtdump.c
index 7300280..5c78559 100644
--- a/fdtdump.c
+++ b/fdtdump.c
@@ -87,6 +87,10 @@ static void dump_blob(void *blob, bool debug)
if (version >= 17)
printf("// size_dt_struct:\t0x%"PRIx32"\n",
fdt32_to_cpu(bph->size_dt_struct));
+ if (version >= 18) {
+ printf("// dt_flags:\t\t0x%"PRIx32"\n",
+ fdt32_to_cpu(bph->dt_flags));
+ }
printf("\n");
for (i = 0; ; i++) {
diff --git a/flattree.c b/flattree.c
index 07f7545..2e2ffcb 100644
--- a/flattree.c
+++ b/flattree.c
@@ -14,6 +14,7 @@
#define FTF_STRUCTSIZE 0x20
#define FTF_NOPS 0x40
#define FTF_REF_XXX 0x80
+#define FTF_DTFLAGS 0x100
static struct version_info {
int version;
@@ -32,7 +33,8 @@ static struct version_info {
{17, 16, FDT_V17_SIZE,
FTF_BOOTCPUID|FTF_STRTABSIZE|FTF_STRUCTSIZE|FTF_NOPS},
{18, 18, FDT_V18_SIZE,
- FTF_BOOTCPUID|FTF_STRTABSIZE|FTF_STRUCTSIZE|FTF_NOPS|FTF_REF_XXX},
+ FTF_BOOTCPUID|FTF_STRTABSIZE|FTF_STRUCTSIZE|FTF_NOPS|FTF_REF_XXX|
+ FTF_DTFLAGS},
};
struct emitter {
@@ -370,7 +372,7 @@ static struct data flatten_reserve_list(struct reserve_info *reservelist,
static void make_fdt_header(struct fdt_header *fdt,
struct version_info *vi,
int reservesize, int dtsize, int strsize,
- int boot_cpuid_phys)
+ int boot_cpuid_phys, uint32_t dt_flags)
{
int reserve_off;
@@ -397,6 +399,8 @@ static void make_fdt_header(struct fdt_header *fdt,
fdt->size_dt_strings = cpu_to_fdt32(strsize);
if (vi->flags & FTF_STRUCTSIZE)
fdt->size_dt_struct = cpu_to_fdt32(dtsize);
+ if (vi->flags & FTF_DTFLAGS)
+ fdt->dt_flags = cpu_to_fdt32(dt_flags);
}
void dt_to_blob(FILE *f, struct dt_info *dti, int version)
@@ -424,7 +428,7 @@ void dt_to_blob(FILE *f, struct dt_info *dti, int version)
/* Make header */
make_fdt_header(&fdt, vi, reservebuf.len, dtbuf.len, strbuf.len,
- dti->boot_cpuid_phys);
+ dti->boot_cpuid_phys, 0);
/*
* If the user asked for more space than is used, adjust the totalsize.
@@ -555,6 +559,11 @@ void dt_to_asm(FILE *f, struct dt_info *dti, int version)
symprefix, symprefix);
}
+ if (vi->flags & FTF_DTFLAGS) {
+ fprintf(f, "\t/* dt_flags */\n");
+ asm_emit_cell(f, 0);
+ }
+
/*
* Reserve map entries.
* Align the reserve map to a doubleword boundary.
@@ -980,7 +989,7 @@ struct dt_info *dt_from_blob(const char *fname)
}
if (version >= 18)
- flags |= FTF_REF_XXX;
+ flags |= FTF_REF_XXX | FTF_DTFLAGS;
inbuf_init(&memresvbuf,
blob + off_mem_rsvmap, blob + totalsize);
diff --git a/libfdt/fdt.h b/libfdt/fdt.h
index 530d2e5..128e7bc 100644
--- a/libfdt/fdt.h
+++ b/libfdt/fdt.h
@@ -26,6 +26,9 @@ struct fdt_header {
/* version 17 fields below */
fdt32_t size_dt_struct; /* size of the structure block */
+
+ /* version 18 fields below */
+ fdt32_t dt_flags; /* Ored value of FDT_FLAG_XXXX */
};
struct fdt_reserve_entry {
@@ -65,6 +68,6 @@ struct fdt_property {
#define FDT_V3_SIZE (FDT_V2_SIZE + sizeof(fdt32_t))
#define FDT_V16_SIZE FDT_V3_SIZE
#define FDT_V17_SIZE (FDT_V16_SIZE + sizeof(fdt32_t))
-#define FDT_V18_SIZE FDT_V17_SIZE
+#define FDT_V18_SIZE (FDT_V17_SIZE + sizeof(fdt32_t))
#endif /* FDT_H */
diff --git a/libfdt/fdt_rw.c b/libfdt/fdt_rw.c
index 00e32bb..1528b33 100644
--- a/libfdt/fdt_rw.c
+++ b/libfdt/fdt_rw.c
@@ -457,6 +457,8 @@ int fdt_open_into(const void *fdt, void *buf, int bufsize)
return err;
fdt_set_version(buf, 18);
fdt_set_last_comp_version(buf, 18);
+ if (can_assume(LATEST) || fdt_version(fdt) < 18)
+ fdt_set_dt_flags(buf, 0);
fdt_set_size_dt_struct(buf, struct_size);
fdt_set_totalsize(buf, bufsize);
return 0;
@@ -487,6 +489,8 @@ int fdt_open_into(const void *fdt, void *buf, int bufsize)
fdt_set_totalsize(buf, bufsize);
fdt_set_version(buf, 18);
fdt_set_last_comp_version(buf, 18);
+ if (can_assume(LATEST) || fdt_version(fdt) < 18)
+ fdt_set_dt_flags(buf, 0);
fdt_set_boot_cpuid_phys(buf, fdt_boot_cpuid_phys(fdt));
return 0;
diff --git a/libfdt/libfdt.h b/libfdt/libfdt.h
index d1a9cd5..9777f32 100644
--- a/libfdt/libfdt.h
+++ b/libfdt/libfdt.h
@@ -319,6 +319,7 @@ fdt_set_hdr_(last_comp_version)
fdt_set_hdr_(boot_cpuid_phys)
fdt_set_hdr_(size_dt_strings)
fdt_set_hdr_(size_dt_struct)
+fdt_set_hdr_(dt_flags)
#undef fdt_set_hdr_
/**
diff --git a/tests/pylibfdt_tests.py b/tests/pylibfdt_tests.py
index 373e11a..7d5ab0b 100644
--- a/tests/pylibfdt_tests.py
+++ b/tests/pylibfdt_tests.py
@@ -285,9 +285,9 @@ class PyLibfdtBasicTests(unittest.TestCase):
"""Test that we can access the header values"""
self.assertEqual(self.fdt.magic(), 0xd00dfeed)
self.assertEqual(self.fdt.totalsize(), len(self.fdt._fdt))
- self.assertEqual(self.fdt.off_dt_struct(), 88)
- self.assertEqual(self.fdt.off_dt_strings(), 652)
- self.assertEqual(self.fdt.off_mem_rsvmap(), 40)
+ self.assertEqual(self.fdt.off_dt_struct(), 96)
+ self.assertEqual(self.fdt.off_dt_strings(), 660)
+ self.assertEqual(self.fdt.off_mem_rsvmap(), 48)
self.assertEqual(self.fdt.version(), 18)
self.assertEqual(self.fdt.last_comp_version(), 16)
self.assertEqual(self.fdt.boot_cpuid_phys(), 0)
diff --git a/tests/testutils.c b/tests/testutils.c
index 54da2e4..2d5cfb3 100644
--- a/tests/testutils.c
+++ b/tests/testutils.c
@@ -344,7 +344,7 @@ void *open_blob_rw(const void *blob)
{
int err;
void *buf;
- int newsize = fdt_totalsize(blob) + 8;
+ int newsize = fdt_totalsize(blob) + 8 + 4;
buf = xmalloc(newsize);
err = fdt_open_into(blob, buf, newsize);
diff --git a/tests/trees.S b/tests/trees.S
index ecd43bc..56c1002 100644
--- a/tests/trees.S
+++ b/tests/trees.S
@@ -22,6 +22,7 @@
fdtlong 0
fdtlong (\tree\()_strings_end - \tree\()_strings)
fdtlong (\tree\()_struct_end - \tree\()_struct)
+ fdtlong 0
.endm
.macro rsvmape addrh, addrl, lenh, lenl
--
2.52.0
Powered by blists - more mailing lists