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

powerpc: Hard wire PT_SOFTE value to 1 in ptrace & signals

Browse Source 
We have always had softe in pt_regs, and accessible via PT_SOFTE, even
though it is not userspace state.

The value userspace sees should always be 1, because we should never
be in userspace with interrupts soft disabled.

In a subsequent patch we will be changing the semantics of the kernel
softe value, so hard wire the value to 1 to retain the existing
semantics. As far as we know nothing ever looks at it, but better safe
than sorry.

Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
[mpe: Split out of larger patch, write change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Madhavan Srinivasan
2017-08-20 23:28:24 +05:30
committed by Michael Ellerman
parent 7a074fc083
commit a8a4b03ab9
3 changed files with 23 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
arch/powerpc/kernel/signal_32.c
View File

@@ -111,12 +111,20 @@ static inline int save_general_regs(struct pt_regs *regs,
{
elf_greg_t64 *gregs = (elf_greg_t64 *)regs;
int i;
/* Force usr to alway see softe as 1 (interrupts enabled) */
elf_greg_t64 softe = 0x1;
WARN_ON(!FULL_REGS(regs));
for (i = 0; i <= PT_RESULT; i ++) {
if (i == 14 && !FULL_REGS(regs))
i = 32;
if ( i == PT_SOFTE) {
if(__put_user((unsigned int)softe, &frame->mc_gregs[i]))
return -EFAULT;
else
continue;
}
if (__put_user((unsigned int)gregs[i], &frame->mc_gregs[i]))
return -EFAULT;
}