xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

powerpc: Add ppc_strict_facility_enable boot option

Browse Source 
Add a boot option that strictly manages the MSR unavailable bits.
This catches kernel uses of FP/Altivec/SPE that would otherwise
corrupt user state.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Anton Blanchard
2015-10-29 11:44:06 +11:00
committed by Michael Ellerman
parent dc4fbba11e
commit 3eb5d5888d
4 changed files with 49 additions and 7 deletions
Download Patch File Download Diff File Expand all files Collapse all files

17
arch/powerpc/kernel/process.c
View File

@@ -87,7 +87,19 @@ static void check_if_tm_restore_required(struct task_struct *tsk)
static inline void check_if_tm_restore_required(struct task_struct *tsk) { }
#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
static void msr_check_and_set(unsigned long bits)
bool strict_msr_control;
EXPORT_SYMBOL(strict_msr_control);
static int __init enable_strict_msr_control(char *str)
{
strict_msr_control = true;
pr_info("Enabling strict facility control\n");
return 0;
}
early_param("ppc_strict_facility_enable", enable_strict_msr_control);
void msr_check_and_set(unsigned long bits)
{
unsigned long oldmsr = mfmsr();
unsigned long newmsr;
@@ -103,7 +115,7 @@ static void msr_check_and_set(unsigned long bits)
mtmsr_isync(newmsr);
}
static void msr_check_and_clear(unsigned long bits)
void __msr_check_and_clear(unsigned long bits)
{
unsigned long oldmsr = mfmsr();
unsigned long newmsr;
@@ -118,6 +130,7 @@ static void msr_check_and_clear(unsigned long bits)
if (oldmsr != newmsr)
mtmsr_isync(newmsr);
}
EXPORT_SYMBOL(__msr_check_and_clear);
#ifdef CONFIG_PPC_FPU
void giveup_fpu(struct task_struct *tsk)