From f9004dbfff8a3fbbd7e2a88c8a4327c7f2f8e5b2 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Wed, 31 Jan 2024 01:04:47 +0000
Subject: [PATCH] add driver 5G
---
kernel/arch/powerpc/kernel/signal_64.c | 87 ++++++++++++++++++++++++++-----------------
1 files changed, 53 insertions(+), 34 deletions(-)
diff --git a/kernel/arch/powerpc/kernel/signal_64.c b/kernel/arch/powerpc/kernel/signal_64.c
index 7aba592..bfc9393 100644
--- a/kernel/arch/powerpc/kernel/signal_64.c
+++ b/kernel/arch/powerpc/kernel/signal_64.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/*
* PowerPC version
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
@@ -5,11 +6,6 @@
* Derived from "arch/i386/kernel/signal.c"
* Copyright (C) 1991, 1992 Linus Torvalds
* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
*/
#include <linux/sched.h>
@@ -25,11 +21,11 @@
#include <linux/ptrace.h>
#include <linux/ratelimit.h>
#include <linux/syscalls.h>
+#include <linux/pagemap.h>
#include <asm/sigcontext.h>
#include <asm/ucontext.h>
#include <linux/uaccess.h>
-#include <asm/pgtable.h>
#include <asm/unistd.h>
#include <asm/cacheflush.h>
#include <asm/syscalls.h>
@@ -44,8 +40,8 @@
#define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
#define FP_REGS_SIZE sizeof(elf_fpregset_t)
-#define TRAMP_TRACEBACK 3
-#define TRAMP_SIZE 6
+#define TRAMP_TRACEBACK 4
+#define TRAMP_SIZE 7
/*
* When we have signals to deliver, we set up on the user stack,
@@ -354,8 +350,8 @@
err |= __get_user(regs->link, &sc->gp_regs[PT_LNK]);
err |= __get_user(regs->xer, &sc->gp_regs[PT_XER]);
err |= __get_user(regs->ccr, &sc->gp_regs[PT_CCR]);
- /* skip SOFTE */
- regs->trap = 0;
+ /* Don't allow userspace to set SOFTE */
+ set_trap_norestart(regs);
err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]);
err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]);
err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]);
@@ -376,7 +372,7 @@
err |= __get_user(v_regs, &sc->v_regs);
if (err)
return err;
- if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128)))
+ if (v_regs && !access_ok(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) {
@@ -476,10 +472,8 @@
&sc->gp_regs[PT_XER]);
err |= __get_user(tsk->thread.ckpt_regs.ccr,
&sc->gp_regs[PT_CCR]);
-
- /* Don't allow userspace to set the trap value */
- regs->trap = 0;
-
+ /* Don't allow userspace to set SOFTE */
+ set_trap_norestart(regs);
/* These regs are not checkpointed; they can go in 'regs'. */
err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]);
err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]);
@@ -497,10 +491,9 @@
err |= __get_user(tm_v_regs, &tm_sc->v_regs);
if (err)
return err;
- if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128)))
+ if (v_regs && !access_ok(v_regs, 34 * sizeof(vector128)))
return -EFAULT;
- if (tm_v_regs && !access_ok(VERIFY_READ,
- tm_v_regs, 34 * sizeof(vector128)))
+ if (tm_v_regs && !access_ok(tm_v_regs, 34 * sizeof(vector128)))
return -EFAULT;
/* Copy 33 vec registers (vr0..31 and vscr) from the stack */
if (v_regs != NULL && tm_v_regs != NULL && (msr & MSR_VEC) != 0) {
@@ -561,7 +554,7 @@
preempt_disable();
/* pull in MSR TS bits from user context */
- regs->msr = (regs->msr & ~MSR_TS_MASK) | (msr & MSR_TS_MASK);
+ regs->msr |= msr & MSR_TS_MASK;
/*
* Ensure that TM is enabled in regs->msr before we leave the signal
@@ -608,12 +601,15 @@
int i;
long err = 0;
+ /* bctrl # call the handler */
+ err |= __put_user(PPC_INST_BCTRL, &tramp[0]);
/* addi r1, r1, __SIGNAL_FRAMESIZE # Pop the dummy stackframe */
- err |= __put_user(0x38210000UL | (__SIGNAL_FRAMESIZE & 0xffff), &tramp[0]);
+ err |= __put_user(PPC_INST_ADDI | __PPC_RT(R1) | __PPC_RA(R1) |
+ (__SIGNAL_FRAMESIZE & 0xffff), &tramp[1]);
/* li r0, __NR_[rt_]sigreturn| */
- err |= __put_user(0x38000000UL | (syscall & 0xffff), &tramp[1]);
+ err |= __put_user(PPC_INST_ADDI | (syscall & 0xffff), &tramp[2]);
/* sc */
- err |= __put_user(0x44000002UL, &tramp[2]);
+ err |= __put_user(PPC_INST_SC, &tramp[3]);
/* Minimal traceback info */
for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++)
@@ -639,7 +635,6 @@
SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
struct ucontext __user *, new_ctx, long, ctx_size)
{
- unsigned char tmp;
sigset_t set;
unsigned long new_msr = 0;
int ctx_has_vsx_region = 0;
@@ -665,7 +660,7 @@
ctx_has_vsx_region = 1;
if (old_ctx != NULL) {
- if (!access_ok(VERIFY_WRITE, old_ctx, ctx_size)
+ if (!access_ok(old_ctx, ctx_size)
|| setup_sigcontext(&old_ctx->uc_mcontext, current, 0, NULL, 0,
ctx_has_vsx_region)
|| __copy_to_user(&old_ctx->uc_sigmask,
@@ -674,9 +669,8 @@
}
if (new_ctx == NULL)
return 0;
- if (!access_ok(VERIFY_READ, new_ctx, ctx_size)
- || __get_user(tmp, (u8 __user *) new_ctx)
- || __get_user(tmp, (u8 __user *) new_ctx + ctx_size - 1))
+ if (!access_ok(new_ctx, ctx_size) ||
+ fault_in_pages_readable((u8 __user *)new_ctx, ctx_size))
return -EFAULT;
/*
@@ -719,7 +713,7 @@
/* Always make any pending restarted system calls return -EINTR */
current->restart_block.fn = do_no_restart_syscall;
- if (!access_ok(VERIFY_READ, uc, sizeof(*uc)))
+ if (!access_ok(uc, sizeof(*uc)))
goto badframe;
if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
@@ -739,6 +733,31 @@
*/
if (MSR_TM_SUSPENDED(mfmsr()))
tm_reclaim_current(0);
+
+ /*
+ * Disable MSR[TS] bit also, so, if there is an exception in the
+ * code below (as a page fault in copy_ckvsx_to_user()), it does
+ * not recheckpoint this task if there was a context switch inside
+ * the exception.
+ *
+ * A major page fault can indirectly call schedule(). A reschedule
+ * process in the middle of an exception can have a side effect
+ * (Changing the CPU MSR[TS] state), since schedule() is called
+ * with the CPU MSR[TS] disable and returns with MSR[TS]=Suspended
+ * (switch_to() calls tm_recheckpoint() for the 'new' process). In
+ * this case, the process continues to be the same in the CPU, but
+ * the CPU state just changed.
+ *
+ * This can cause a TM Bad Thing, since the MSR in the stack will
+ * have the MSR[TS]=0, and this is what will be used to RFID.
+ *
+ * Clearing MSR[TS] state here will avoid a recheckpoint if there
+ * is any process reschedule in kernel space. The MSR[TS] state
+ * does not need to be saved also, since it will be replaced with
+ * the MSR[TS] that came from user context later, at
+ * restore_tm_sigcontexts.
+ */
+ regs->msr &= ~MSR_TS_MASK;
if (__get_user(msr, &uc->uc_mcontext.gp_regs[PT_MSR]))
goto badframe;
@@ -787,7 +806,7 @@
current->comm, current->pid, "rt_sigreturn",
(long)uc, regs->nip, regs->link);
- force_sig(SIGSEGV, current);
+ force_sig(SIGSEGV);
return 0;
}
@@ -846,12 +865,12 @@
/* Set up to return from userspace. */
if (vdso64_rt_sigtramp && tsk->mm->context.vdso_base) {
- regs->link = tsk->mm->context.vdso_base + vdso64_rt_sigtramp;
+ regs->nip = tsk->mm->context.vdso_base + vdso64_rt_sigtramp;
} else {
err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]);
if (err)
goto badframe;
- regs->link = (unsigned long) &frame->tramp[0];
+ regs->nip = (unsigned long) &frame->tramp[0];
}
/* Allocate a dummy caller frame for the signal handler. */
@@ -860,8 +879,8 @@
/* Set up "regs" so we "return" to the signal handler. */
if (is_elf2_task()) {
- regs->nip = (unsigned long) ksig->ka.sa.sa_handler;
- regs->gpr[12] = regs->nip;
+ regs->ctr = (unsigned long) ksig->ka.sa.sa_handler;
+ regs->gpr[12] = regs->ctr;
} else {
/* Handler is *really* a pointer to the function descriptor for
* the signal routine. The first entry in the function
@@ -871,7 +890,7 @@
func_descr_t __user *funct_desc_ptr =
(func_descr_t __user *) ksig->ka.sa.sa_handler;
- err |= get_user(regs->nip, &funct_desc_ptr->entry);
+ err |= get_user(regs->ctr, &funct_desc_ptr->entry);
err |= get_user(regs->gpr[2], &funct_desc_ptr->toc);
}
--
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