Additional patch suggestion to go with the rtas devices:
-----------------------------------------------------------------------
With most important rtas functions available through different
interfaces the sys_rtas interface can be disabled completely.
Do not remove it for now to make it possible to run older versions of
userspace tools that don't support other interfaces.
Signed-off-by: Michal Suchanek <msucha...@suse.de>
---
arch/powerpc/kernel/rtas.c | 2 ++
arch/powerpc/platforms/Kconfig | 9 +++++++++
2 files changed, 11 insertions(+)
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index eddc031c4b95..5854a8bb5731 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -1684,6 +1684,7 @@ noinstr struct pseries_errorlog
*get_pseries_errorlog(struct rtas_error_log *log
return NULL;
}
+#ifdef PPC_RTAS_SYSCALL
/*
* The sys_rtas syscall, as originally designed, allows root to pass
* arbitrary physical addresses to RTAS calls. A number of RTAS calls
@@ -1893,6 +1894,7 @@ SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs)
return 0;
}
+#endif
static void __init rtas_function_table_init(void)
{
diff --git a/arch/powerpc/platforms/Kconfig b/arch/powerpc/platforms/Kconfig
index 1fd253f92a77..9563e38188d5 100644
--- a/arch/powerpc/platforms/Kconfig
+++ b/arch/powerpc/platforms/Kconfig
@@ -150,6 +150,15 @@ config RTAS_FLASH
tristate "Firmware flash interface"
depends on PPC64 && RTAS_PROC
+config RTAS_SYSCALL
+ bool "Legacy syscall interface to RTAS"
+ depends on PPC_RTAS
+ default y
+ help
+ Enables support for the legacy sys_rtas interface. Calls that need to
+ pass data buffers use /dev/mem directly which is not compatible with
+ lockdown. For now some tools still need this interface to work.
+
config MMIO_NVRAM
bool
--
2.41.0
