adulau/aha
1
0
Fork 0
mirror of https://github.com/adulau/aha.git synced 2024-12-31 21:26:18 +00:00
Code Issues Projects Releases Packages Wiki Activity

powerpc: Fix msr check in compat_sys_swapcontext

Browse source 
The new context may not be 16-byte aligned, so the real address of the
mcontext structure should be read from the uc_regs pointer instead of
directly using the (unaligned) uc_mcontext field.

Signed-off-by: Andreas Schwab <schwab@suse.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
Andreas Schwab 2008-11-06 00:49:00 +00:00 committed by Paul Mackerras
parent ec5d7657f7
commit 77eb50aefa
1 changed files with 15 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

18
arch/powerpc/kernel/signal_32.c
View file

@ -941,9 +941,21 @@ long sys_swapcontext(struct ucontext __user *old_ctx,
#ifdef CONFIG_PPC64 #ifdef CONFIG_PPC64
unsigned long new_msr = 0; unsigned long new_msr = 0;
if (new_ctx && if (new_ctx) {
get_user(new_msr, &new_ctx->uc_mcontext.mc_gregs[PT_MSR])) struct mcontext __user *mcp;
return -EFAULT; u32 cmcp;
/*
* Get pointer to the real mcontext. No need for
* access_ok since we are dealing with compat
* pointers.
*/
if (__get_user(cmcp, &new_ctx->uc_regs))
return -EFAULT;
mcp = (struct mcontext __user *)(u64)cmcp;
if (__get_user(new_msr, &mcp->mc_gregs[PT_MSR]))
return -EFAULT;
}
/* /*
* Check that the context is not smaller than the original * Check that the context is not smaller than the original
* size (with VMX but without VSX) * size (with VMX but without VSX)