[PATCH 1/6] powerpc/64/kuap: move kuap checks out of MSR[RI]=0 regions of exit code
From: Nicholas Piggin <npiggin@gmail.com>
Date: 2020-04-29 06:30:03
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
Any kind of WARN causes a program check that will crash with unrecoverable exception if it occurs when RI is clear. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- arch/powerpc/kernel/syscall_64.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/kernel/syscall_64.c b/arch/powerpc/kernel/syscall_64.c
index 8f7e268f3294..a37c7717424f 100644
--- a/arch/powerpc/kernel/syscall_64.c
+++ b/arch/powerpc/kernel/syscall_64.c@@ -35,6 +35,8 @@ notrace long system_call_exception(long r3, long r4, long r5, BUG_ON(!FULL_REGS(regs)); BUG_ON(regs->softe != IRQS_ENABLED); + kuap_check_amr(); + account_cpu_user_entry(); #ifdef CONFIG_PPC_SPLPAR
@@ -47,8 +49,6 @@ notrace long system_call_exception(long r3, long r4, long r5, } #endif - kuap_check_amr(); - /* * This is not required for the syscall exit path, but makes the * stack frame look nicer. If this was initialised in the first stack
@@ -142,6 +142,8 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3, unsigned long ti_flags; unsigned long ret = 0; + kuap_check_amr(); + regs->result = r3; /* Check whether the syscall is issued inside a restartable sequence */
@@ -218,8 +220,6 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3, local_paca->tm_scratch = regs->msr; #endif - kuap_check_amr(); - account_cpu_user_exit(); return ret;
@@ -242,6 +242,8 @@ notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned BUG_ON(!FULL_REGS(regs)); BUG_ON(regs->softe != IRQS_ENABLED); + kuap_check_amr(); + local_irq_save(flags); again:
@@ -298,8 +300,6 @@ notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned local_paca->tm_scratch = regs->msr; #endif - kuap_check_amr(); - account_cpu_user_exit(); return ret;
@@ -319,6 +319,8 @@ notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs, unsign BUG_ON(regs->msr & MSR_PR); BUG_ON(!FULL_REGS(regs)); + kuap_check_amr(); + if (unlikely(*ti_flagsp & _TIF_EMULATE_STACK_STORE)) { clear_bits(_TIF_EMULATE_STACK_STORE, ti_flagsp); ret = 1;
--
2.23.0