[PATCH 13/14] powerpc/rtas: enture rtas_call is called with MMU enabled
From: Nicholas Piggin <npiggin@gmail.com>
Date: 2022-03-08 13:59:44
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
rtas_call must not be called with the MMU disabled because in case of rtas error, log_error is called which requires MMU enabled. Add a test and warning for this. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- arch/powerpc/kernel/rtas.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index 1fc22138e3ab..adf4892aeecd 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c@@ -479,6 +479,11 @@ int rtas_call(int token, int nargs, int nret, int *outputs, ...) if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE) return -1; + if ((mfmsr() & (MSR_IR|MSR_DR)) != (MSR_IR|MSR_DR)) { + WARN_ON_ONCE(1); + return -1; + } + s = lock_rtas(); /* We use the global rtas args buffer */
--
2.23.0