From: Nicholas Piggin <npiggin@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Nicholas Piggin <npiggin@gmail.com>
Subject: [PATCH 1/6] powerpc/64/kuap: move kuap checks out of MSR[RI]=0 regions of exit code
Date: Wed, 29 Apr 2020 16:56:49 +1000 [thread overview]
Message-ID: <20200429065654.1677541-2-npiggin@gmail.com> (raw)
In-Reply-To: <20200429065654.1677541-1-npiggin@gmail.com>
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
next prev parent reply other threads:[~2020-04-29 7:01 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-29 6:56 [PATCH 0/6] assorted kuap fixes (try again) Nicholas Piggin
2020-04-29 6:56 ` Nicholas Piggin [this message]
2020-04-29 6:56 ` [PATCH 2/6] powerpc/64s/kuap: kuap_restore missing isync Nicholas Piggin
2020-04-29 6:56 ` [PATCH 3/6] powerpc/64/kuap: interrupt exit conditionally restore AMR Nicholas Piggin
2020-04-29 6:56 ` [PATCH 4/6] powerpc/64s/kuap: restore AMR in system reset exception Nicholas Piggin
2020-04-29 6:56 ` [PATCH 5/6] powerpc/64s/kuap: restore AMR in fast_interrupt_return Nicholas Piggin
2020-04-29 6:56 ` [PATCH 6/6] powerpc/64s/kuap: conditionally restore AMR in kuap_restore_amr asm Nicholas Piggin
2020-06-09 5:54 ` [PATCH 0/6] assorted kuap fixes (try again) Michael Ellerman
-- strict thread matches above, loose matches on Subject: below --
2020-04-29 6:26 [PATCH 0/6] assorted kuap fixes Nicholas Piggin
2020-04-29 6:26 ` [PATCH 1/6] powerpc/64/kuap: move kuap checks out of MSR[RI]=0 regions of exit code Nicholas Piggin
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