On 3/11/24 13:24, Christophe Leroy wrote:
Le 11/03/2024 à 14:20, Stefan Berger a écrit :
linux,sml-base holds the address of a buffer with the TPM log. This
buffer may become invalid after a kexec. To avoid accessing an invalid
address or corrupted buffer, embed the whole TPM log in the device tree
property linux,sml-log. This helps to protect the log since it is
properly carried across a kexec soft reboot with both of the kexec
syscalls.
Avoid having the firmware ingest the whole TPM log when calling
prom_setprop but only create the linux,sml-log property as a place holder.
Insert the actual TPM log during the tree flattening phase.
Fixes: 4a727429abec ("PPC64: Add support for instantiating SML from Open Firmware")
Suggested-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Stefan Berger <stefanb@xxxxxxxxxxxxx>
---
@@ -2645,6 +2645,17 @@ static void __init scan_dt_build_struct(phandle node, unsigned long *mem_start,
}
prev_name = sstart + soff;
+ if (!prom_strcmp("linux,sml-log", pname)) {
+ /* push property head */
+ dt_push_token(OF_DT_PROP, mem_start, mem_end);
+ dt_push_token(sml_size, mem_start, mem_end);
+ dt_push_token(soff, mem_start, mem_end);
+ /* push property content */
+ valp = make_room(mem_start, mem_end, sml_size, 1);
+ memcpy(valp, (void *)sml_base, sml_size);
You can't cast a u64 into a pointer. If sml_base is an address, it must
be declared as an unsigned long.
Build with pmac32_defconfig :
CC arch/powerpc/kernel/prom_init.o
arch/powerpc/kernel/prom_init.c: In function 'scan_dt_build_struct':
arch/powerpc/kernel/prom_init.c:2663:38: error: cast to pointer from
integer of different size [-Werror=int-to-pointer-cast]
2663 | memcpy(valp, (void *)sml_base, sml_size);
| ^
cc1: all warnings being treated as errors
make[4]: *** [scripts/Makefile.build:243:
arch/powerpc/kernel/prom_init.o] Error 1
Next round will have this block under #ifdef CONFIG_PPC64.
Thanks.
