Re: [v4] powerpc: Export thread_struct.used_vr/used_vsr to user space
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: 2016-07-07 13:30:08
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
On Thu, 2016-07-07 at 23:21 +1000, Benjamin Herrenschmidt wrote:
I think the right fix is that if a restore_sigcontext() has the MSR bits set, it should set the corresponding used_* flag.
Something like this: (totally untested)
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index b6aa378..1bf074e 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c@@ -698,6 +698,7 @@ static long restore_user_regs(struct pt_regs *regs, if (__copy_from_user(¤t->thread.vr_state, &sr->mc_vregs, sizeof(sr->mc_vregs))) return 1; + current->thread.used_vr = true; } else if (current->thread.used_vr) memset(¤t->thread.vr_state, 0, ELF_NVRREG * sizeof(vector128));
@@ -724,6 +725,7 @@ static long restore_user_regs(struct pt_regs *regs, */ if (copy_vsx_from_user(current, &sr->mc_vsregs)) return 1; + current->thread.used_vsr = true; } else if (current->thread.used_vsr) for (i = 0; i < 32 ; i++) current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
@@ -743,6 +745,7 @@ static long restore_user_regs(struct pt_regs *regs, if (__copy_from_user(current->thread.evr, &sr->mc_vregs, ELF_NEVRREG * sizeof(u32))) return 1; + current->thread.used_spe = true; } else if (current->thread.used_spe) memset(current->thread.evr, 0, ELF_NEVRREG * sizeof(u32));
@@ -799,6 +802,7 @@ static long restore_tm_user_regs(struct pt_regs *regs, &tm_sr->mc_vregs, sizeof(sr->mc_vregs))) return 1; + current->thread.used_vr = true; } else if (current->thread.used_vr) { memset(¤t->thread.vr_state, 0, ELF_NVRREG * sizeof(vector128));
@@ -832,6 +836,7 @@ static long restore_tm_user_regs(struct pt_regs *regs, if (copy_vsx_from_user(current, &sr->mc_vsregs) || copy_transact_vsx_from_user(current, &tm_sr->mc_vsregs)) return 1; + current->thread.used_vsr = true; } else if (current->thread.used_vsr) for (i = 0; i < 32 ; i++) { current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
@@ -848,6 +853,7 @@ static long restore_tm_user_regs(struct pt_regs *regs, if (__copy_from_user(current->thread.evr, &sr->mc_vregs, ELF_NEVRREG * sizeof(u32))) return 1; + current->thread.used_spe = true; } else if (current->thread.used_spe) memset(current->thread.evr, 0, ELF_NEVRREG * sizeof(u32));
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index 2552079..8704269 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c@@ -363,9 +363,11 @@ static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig, if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128))) return -EFAULT; /* Copy 33 vec registers (vr0..31 and vscr) from the stack */ - if (v_regs != NULL && (msr & MSR_VEC) != 0) + if (v_regs != NULL && (msr & MSR_VEC) != 0) { err |= __copy_from_user(¤t->thread.vr_state, v_regs, 33 * sizeof(vector128)); + current->thread.used_vr = true; + } else if (current->thread.used_vr) memset(¤t->thread.vr_state, 0, 33 * sizeof(vector128)); /* Always get VRSAVE back */
@@ -385,9 +387,10 @@ static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig, * buffer for formatting, then into the taskstruct. */ v_regs += ELF_NVRREG; - if ((msr & MSR_VSX) != 0) + if ((msr & MSR_VSX) != 0) { err |= copy_vsx_from_user(current, v_regs); - else + current->thread.used_vsr = true; + } else for (i = 0; i < 32 ; i++) current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0; #endif
@@ -482,6 +485,7 @@ static long restore_tm_sigcontexts(struct pt_regs *regs, 33 * sizeof(vector128)); err |= __copy_from_user(¤t->thread.transact_vr, tm_v_regs, 33 * sizeof(vector128)); + current->thread.used_vr = true; } else if (current->thread.used_vr) { memset(¤t->thread.vr_state, 0, 33 * sizeof(vector128));
@@ -515,6 +519,7 @@ static long restore_tm_sigcontexts(struct pt_regs *regs, tm_v_regs += ELF_NVRREG; err |= copy_vsx_from_user(current, v_regs); err |= copy_transact_vsx_from_user(current, tm_v_regs); + current->thread.used_vsr = true; } else { for (i = 0; i < 32 ; i++) { current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;