From 04dd17822334871b23ea2862f7798fb0e0007777 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Sat, 11 May 2024 08:53:19 +0000
Subject: [PATCH] change otg to host mode
---
kernel/arch/arm/mm/fault.c | 167 +++++++++++++++++++------------------------------------
1 files changed, 58 insertions(+), 109 deletions(-)
diff --git a/kernel/arch/arm/mm/fault.c b/kernel/arch/arm/mm/fault.c
index 20b0e14..af51778 100644
--- a/kernel/arch/arm/mm/fault.c
+++ b/kernel/arch/arm/mm/fault.c
@@ -1,12 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/arch/arm/mm/fault.c
*
* Copyright (C) 1995 Linus Torvalds
* Modifications for ARM processor (c) 1995-2004 Russell King
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
*/
#include <linux/extable.h>
#include <linux/signal.h>
@@ -21,7 +18,6 @@
#include <linux/highmem.h>
#include <linux/perf_event.h>
-#include <asm/pgtable.h>
#include <asm/system_misc.h>
#include <asm/system_info.h>
#include <asm/tlbflush.h>
@@ -30,58 +26,37 @@
#ifdef CONFIG_MMU
-#ifdef CONFIG_KPROBES
-static inline int notify_page_fault(struct pt_regs *regs, unsigned int fsr)
-{
- int ret = 0;
-
- if (!user_mode(regs)) {
- /* kprobe_running() needs smp_processor_id() */
- preempt_disable();
- if (kprobe_running() && kprobe_fault_handler(regs, fsr))
- ret = 1;
- preempt_enable();
- }
-
- return ret;
-}
-#else
-static inline int notify_page_fault(struct pt_regs *regs, unsigned int fsr)
-{
- return 0;
-}
-#endif
-
/*
* This is useful to dump out the page tables associated with
* 'addr' in mm 'mm'.
*/
-void show_pte(struct mm_struct *mm, unsigned long addr)
+void show_pte(const char *lvl, struct mm_struct *mm, unsigned long addr)
{
pgd_t *pgd;
if (!mm)
mm = &init_mm;
- pr_alert("pgd = %p\n", mm->pgd);
+ printk("%spgd = %p\n", lvl, mm->pgd);
pgd = pgd_offset(mm, addr);
- pr_alert("[%08lx] *pgd=%08llx",
- addr, (long long)pgd_val(*pgd));
+ printk("%s[%08lx] *pgd=%08llx", lvl, addr, (long long)pgd_val(*pgd));
do {
+ p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
- if (pgd_none(*pgd))
+ p4d = p4d_offset(pgd, addr);
+ if (p4d_none(*p4d))
break;
- if (pgd_bad(*pgd)) {
+ if (p4d_bad(*p4d)) {
pr_cont("(bad)");
break;
}
- pud = pud_offset(pgd, addr);
+ pud = pud_offset(p4d, addr);
if (PTRS_PER_PUD != 1)
pr_cont(", *pud=%08llx", (long long)pud_val(*pud));
@@ -121,7 +96,7 @@
pr_cont("\n");
}
#else /* CONFIG_MMU */
-void show_pte(struct mm_struct *mm, unsigned long addr)
+void show_pte(const char *lvl, struct mm_struct *mm, unsigned long addr)
{ }
#endif /* CONFIG_MMU */
@@ -142,14 +117,15 @@
* No handler, we'll have to terminate things with extreme prejudice.
*/
bust_spinlocks(1);
+ pr_alert("8<--- cut here ---\n");
pr_alert("Unable to handle kernel %s at virtual address %08lx\n",
(addr < PAGE_SIZE) ? "NULL pointer dereference" :
"paging request", addr);
- show_pte(mm, addr);
+ show_pte(KERN_ALERT, mm, addr);
die("Oops", regs, fsr);
bust_spinlocks(0);
- do_exit(SIGKILL);
+ make_task_dead(SIGKILL);
}
/*
@@ -157,35 +133,35 @@
* User mode accesses just cause a SIGSEGV
*/
static void
-__do_user_fault(struct task_struct *tsk, unsigned long addr,
- unsigned int fsr, unsigned int sig, int code,
- struct pt_regs *regs)
+__do_user_fault(unsigned long addr, unsigned int fsr, unsigned int sig,
+ int code, struct pt_regs *regs)
{
- struct siginfo si;
+ struct task_struct *tsk = current;
if (addr > TASK_SIZE)
harden_branch_predictor();
- clear_siginfo(&si);
-
#ifdef CONFIG_DEBUG_USER
if (((user_debug & UDBG_SEGV) && (sig == SIGSEGV)) ||
((user_debug & UDBG_BUS) && (sig == SIGBUS))) {
- printk(KERN_DEBUG "%s: unhandled page fault (%d) at 0x%08lx, code 0x%03x\n",
+ pr_err("8<--- cut here ---\n");
+ pr_err("%s: unhandled page fault (%d) at 0x%08lx, code 0x%03x\n",
tsk->comm, sig, addr, fsr);
- show_pte(tsk->mm, addr);
+ show_pte(KERN_ERR, tsk->mm, addr);
show_regs(regs);
}
+#endif
+#ifndef CONFIG_KUSER_HELPERS
+ if ((sig == SIGSEGV) && ((addr & PAGE_MASK) == 0xffff0000))
+ printk_ratelimited(KERN_DEBUG
+ "%s: CONFIG_KUSER_HELPERS disabled at 0x%08lx\n",
+ tsk->comm, addr);
#endif
tsk->thread.address = addr;
tsk->thread.error_code = fsr;
tsk->thread.trap_no = 14;
- si.si_signo = sig;
- si.si_errno = 0;
- si.si_code = code;
- si.si_addr = (void __user *)addr;
- force_sig_info(sig, &si, tsk);
+ force_sig_fault(sig, code, (void __user *)addr);
}
void do_bad_area(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
@@ -198,7 +174,7 @@
* have no context to handle this fault with.
*/
if (user_mode(regs))
- __do_user_fault(tsk, addr, fsr, SIGSEGV, SEGV_MAPERR, regs);
+ __do_user_fault(addr, fsr, SIGSEGV, SEGV_MAPERR, regs);
else
__do_kernel_fault(mm, addr, fsr, regs);
}
@@ -214,7 +190,7 @@
*/
static inline bool access_error(unsigned int fsr, struct vm_area_struct *vma)
{
- unsigned int mask = VM_READ | VM_WRITE | VM_EXEC;
+ unsigned int mask = VM_ACCESS_FLAGS;
if ((fsr & FSR_WRITE) && !(fsr & FSR_CM))
mask = VM_WRITE;
@@ -226,7 +202,8 @@
static vm_fault_t __kprobes
__do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr,
- unsigned int flags, struct task_struct *tsk)
+ unsigned int flags, struct task_struct *tsk,
+ struct pt_regs *regs)
{
struct vm_area_struct *vma;
vm_fault_t fault;
@@ -248,7 +225,7 @@
goto out;
}
- return handle_mm_fault(vma, addr & PAGE_MASK, flags);
+ return handle_mm_fault(vma, addr & PAGE_MASK, flags, regs);
check_stack:
/* Don't allow expansion below FIRST_USER_ADDRESS */
@@ -266,9 +243,9 @@
struct mm_struct *mm;
int sig, code;
vm_fault_t fault;
- unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
+ unsigned int flags = FAULT_FLAG_DEFAULT;
- if (notify_page_fault(regs, fsr))
+ if (kprobe_page_fault(regs, fsr))
return 0;
tsk = current;
@@ -290,16 +267,18 @@
if ((fsr & FSR_WRITE) && !(fsr & FSR_CM))
flags |= FAULT_FLAG_WRITE;
+ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr);
+
/*
* As per x86, we may deadlock here. However, since the kernel only
* validly references user space from well defined areas of the code,
* we can bug out early if this is from code which shouldn't.
*/
- if (!down_read_trylock(&mm->mmap_sem)) {
+ if (!mmap_read_trylock(mm)) {
if (!user_mode(regs) && !search_exception_tables(regs->ARM_pc))
goto no_context;
retry:
- down_read(&mm->mmap_sem);
+ mmap_read_lock(mm);
} else {
/*
* The above down_read_trylock() might have succeeded in
@@ -314,45 +293,26 @@
#endif
}
- fault = __do_page_fault(mm, addr, fsr, flags, tsk);
+ fault = __do_page_fault(mm, addr, fsr, flags, tsk, regs);
/* If we need to retry but a fatal signal is pending, handle the
- * signal first. We do not need to release the mmap_sem because
+ * signal first. We do not need to release the mmap_lock because
* it would already be released in __lock_page_or_retry in
* mm/filemap.c. */
- if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) {
+ if (fault_signal_pending(fault, regs)) {
if (!user_mode(regs))
goto no_context;
return 0;
}
- /*
- * Major/minor page fault accounting is only done on the
- * initial attempt. If we go through a retry, it is extremely
- * likely that the page will be found in page cache at that point.
- */
-
- perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr);
if (!(fault & VM_FAULT_ERROR) && flags & FAULT_FLAG_ALLOW_RETRY) {
- if (fault & VM_FAULT_MAJOR) {
- tsk->maj_flt++;
- perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1,
- regs, addr);
- } else {
- tsk->min_flt++;
- perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1,
- regs, addr);
- }
if (fault & VM_FAULT_RETRY) {
- /* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk
- * of starvation. */
- flags &= ~FAULT_FLAG_ALLOW_RETRY;
flags |= FAULT_FLAG_TRIED;
goto retry;
}
}
- up_read(&mm->mmap_sem);
+ mmap_read_unlock(mm);
/*
* Handle the "normal" case first - VM_FAULT_MAJOR
@@ -394,7 +354,7 @@
SEGV_ACCERR : SEGV_MAPERR;
}
- __do_user_fault(tsk, addr, fsr, sig, code, regs);
+ __do_user_fault(addr, fsr, sig, code, regs);
return 0;
no_context:
@@ -433,14 +393,12 @@
{
unsigned int index;
pgd_t *pgd, *pgd_k;
+ p4d_t *p4d, *p4d_k;
pud_t *pud, *pud_k;
pmd_t *pmd, *pmd_k;
if (addr < TASK_SIZE)
return do_page_fault(addr, fsr, regs);
-
- if (interrupts_enabled(regs))
- local_irq_enable();
if (user_mode(regs))
goto bad_area;
@@ -450,13 +408,16 @@
pgd = cpu_get_pgd() + index;
pgd_k = init_mm.pgd + index;
- if (pgd_none(*pgd_k))
- goto bad_area;
- if (!pgd_present(*pgd))
- set_pgd(pgd, *pgd_k);
+ p4d = p4d_offset(pgd, addr);
+ p4d_k = p4d_offset(pgd_k, addr);
- pud = pud_offset(pgd, addr);
- pud_k = pud_offset(pgd_k, addr);
+ if (p4d_none(*p4d_k))
+ goto bad_area;
+ if (!p4d_present(*p4d))
+ set_p4d(p4d, *p4d_k);
+
+ pud = pud_offset(p4d, addr);
+ pud_k = pud_offset(p4d_k, addr);
if (pud_none(*pud_k))
goto bad_area;
@@ -509,9 +470,6 @@
static int
do_sect_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
{
- if (interrupts_enabled(regs))
- local_irq_enable();
-
do_bad_area(addr, fsr, regs);
return 0;
}
@@ -560,21 +518,17 @@
do_DataAbort(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
{
const struct fsr_info *inf = fsr_info + fsr_fs(fsr);
- struct siginfo info;
if (!inf->fn(addr, fsr & ~FSR_LNX_PF, regs))
return;
+ pr_alert("8<--- cut here ---\n");
pr_alert("Unhandled fault: %s (0x%03x) at 0x%08lx\n",
inf->name, fsr, addr);
- show_pte(current->mm, addr);
+ show_pte(KERN_ALERT, current->mm, addr);
- clear_siginfo(&info);
- info.si_signo = inf->sig;
- info.si_errno = 0;
- info.si_code = inf->code;
- info.si_addr = (void __user *)addr;
- arm_notify_die("", regs, &info, fsr, 0);
+ arm_notify_die("", regs, inf->sig, inf->code, (void __user *)addr,
+ fsr, 0);
}
void __init
@@ -594,7 +548,6 @@
do_PrefetchAbort(unsigned long addr, unsigned int ifsr, struct pt_regs *regs)
{
const struct fsr_info *inf = ifsr_info + fsr_fs(ifsr);
- struct siginfo info;
if (!inf->fn(addr, ifsr | FSR_LNX_PF, regs))
return;
@@ -602,12 +555,8 @@
pr_alert("Unhandled prefetch abort: %s (0x%03x) at 0x%08lx\n",
inf->name, ifsr, addr);
- clear_siginfo(&info);
- info.si_signo = inf->sig;
- info.si_errno = 0;
- info.si_code = inf->code;
- info.si_addr = (void __user *)addr;
- arm_notify_die("", regs, &info, ifsr, 0);
+ arm_notify_die("", regs, inf->sig, inf->code, (void __user *)addr,
+ ifsr, 0);
}
/*
--
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