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Diffstat (limited to 'arch/mips/mm/fault.c')
-rw-r--r--arch/mips/mm/fault.c180
1 files changed, 94 insertions, 86 deletions
diff --git a/arch/mips/mm/fault.c b/arch/mips/mm/fault.c
index 85df1cd8d446..37fedeaca2e9 100644
--- a/arch/mips/mm/fault.c
+++ b/arch/mips/mm/fault.c
@@ -14,36 +14,40 @@
#include <linux/string.h>
#include <linux/types.h>
#include <linux/ptrace.h>
+#include <linux/ratelimit.h>
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/smp.h>
-#include <linux/module.h>
#include <linux/kprobes.h>
#include <linux/perf_event.h>
+#include <linux/uaccess.h>
#include <asm/branch.h>
#include <asm/mmu_context.h>
-#include <asm/uaccess.h>
#include <asm/ptrace.h>
#include <asm/highmem.h> /* For VMALLOC_END */
+#include <asm/traps.h>
#include <linux/kdebug.h>
+int show_unhandled_signals = 1;
+
/*
* This routine handles page faults. It determines the address,
* and the problem, and then passes it off to one of the appropriate
* routines.
*/
-static void __kprobes __do_page_fault(struct pt_regs *regs, unsigned long write,
+static void __do_page_fault(struct pt_regs *regs, unsigned long write,
unsigned long address)
{
struct vm_area_struct * vma = NULL;
struct task_struct *tsk = current;
struct mm_struct *mm = tsk->mm;
const int field = sizeof(unsigned long) * 2;
- siginfo_t info;
- int fault;
- unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE |
- (write ? FAULT_FLAG_WRITE : 0);
+ int si_code;
+ vm_fault_t fault;
+ unsigned int flags = FAULT_FLAG_DEFAULT;
+
+ static DEFINE_RATELIMIT_STATE(ratelimit_state, 5 * HZ, 10);
#if 0
printk("Cpu%d[%s:%d:%0*lx:%ld:%0*lx]\n", raw_smp_processor_id(),
@@ -53,16 +57,14 @@ static void __kprobes __do_page_fault(struct pt_regs *regs, unsigned long write,
#ifdef CONFIG_KPROBES
/*
- * This is to notify the fault handler of the kprobes. The
- * exception code is redundant as it is also carried in REGS,
- * but we pass it anyhow.
+ * This is to notify the fault handler of the kprobes.
*/
if (notify_die(DIE_PAGE_FAULT, "page fault", regs, -1,
- (regs->cp0_cause >> 2) & 0x1f, SIGSEGV) == NOTIFY_STOP)
+ current->thread.trap_nr, SIGSEGV) == NOTIFY_STOP)
return;
#endif
- info.si_code = SEGV_MAPERR;
+ si_code = SEGV_MAPERR;
/*
* We fault-in kernel-space virtual memory on-demand. The
@@ -81,8 +83,8 @@ static void __kprobes __do_page_fault(struct pt_regs *regs, unsigned long write,
if (unlikely(address >= VMALLOC_START && address <= VMALLOC_END))
goto VMALLOC_FAULT_TARGET;
-#ifdef MODULE_START
- if (unlikely(address >= MODULE_START && address < MODULE_END))
+#ifdef MODULES_VADDR
+ if (unlikely(address >= MODULES_VADDR && address < MODULES_END))
goto VMALLOC_FAULT_TARGET;
#endif
@@ -90,30 +92,27 @@ static void __kprobes __do_page_fault(struct pt_regs *regs, unsigned long write,
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (faulthandler_disabled() || !mm)
goto bad_area_nosemaphore;
+ if (user_mode(regs))
+ flags |= FAULT_FLAG_USER;
+
+ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
retry:
- down_read(&mm->mmap_sem);
- vma = find_vma(mm, address);
+ vma = lock_mm_and_find_vma(mm, address, regs);
if (!vma)
- goto bad_area;
- if (vma->vm_start <= address)
- goto good_area;
- if (!(vma->vm_flags & VM_GROWSDOWN))
- goto bad_area;
- if (expand_stack(vma, address))
- goto bad_area;
+ goto bad_area_nosemaphore;
/*
* Ok, we have a good vm_area for this memory access, so
* we can handle it..
*/
-good_area:
- info.si_code = SEGV_ACCERR;
+ si_code = SEGV_ACCERR;
if (write) {
if (!(vma->vm_flags & VM_WRITE))
goto bad_area;
+ flags |= FAULT_FLAG_WRITE;
} else {
if (cpu_has_rixi) {
if (address == regs->cp0_epc && !(vma->vm_flags & VM_EXEC)) {
@@ -126,7 +125,8 @@ good_area:
#endif
goto bad_area;
}
- if (!(vma->vm_flags & VM_READ)) {
+ if (!(vma->vm_flags & VM_READ) &&
+ exception_epc(regs) != address) {
#if 0
pr_notice("Cpu%d[%s:%d:%0*lx:%ld:%0*lx] RI violation\n",
raw_smp_processor_id(),
@@ -137,7 +137,7 @@ good_area:
goto bad_area;
}
} else {
- if (!(vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC)))
+ if (unlikely(!vma_is_accessible(vma)))
goto bad_area;
}
}
@@ -147,44 +147,41 @@ good_area:
* make sure we exit gracefully rather than endlessly redo
* the fault.
*/
- fault = handle_mm_fault(mm, vma, address, flags);
+ fault = handle_mm_fault(vma, address, flags, regs);
- if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
+ if (fault_signal_pending(fault, regs)) {
+ if (!user_mode(regs))
+ goto no_context;
+ return;
+ }
+
+ /* The fault is fully completed (including releasing mmap lock) */
+ if (fault & VM_FAULT_COMPLETED)
return;
- perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
if (unlikely(fault & VM_FAULT_ERROR)) {
if (fault & VM_FAULT_OOM)
goto out_of_memory;
+ else if (fault & VM_FAULT_SIGSEGV)
+ goto bad_area;
else if (fault & VM_FAULT_SIGBUS)
goto do_sigbus;
BUG();
}
- if (flags & FAULT_FLAG_ALLOW_RETRY) {
- if (fault & VM_FAULT_MAJOR) {
- perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1,
- regs, address);
- tsk->maj_flt++;
- } else {
- perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1,
- regs, address);
- tsk->min_flt++;
- }
- if (fault & VM_FAULT_RETRY) {
- flags &= ~FAULT_FLAG_ALLOW_RETRY;
- flags |= FAULT_FLAG_TRIED;
- /*
- * No need to up_read(&mm->mmap_sem) as we would
- * have already released it in __lock_page_or_retry
- * in mm/filemap.c.
- */
+ if (fault & VM_FAULT_RETRY) {
+ flags |= FAULT_FLAG_TRIED;
- goto retry;
- }
+ /*
+ * No need to mmap_read_unlock(mm) as we would
+ * have already released it in __lock_page_or_retry
+ * in mm/filemap.c.
+ */
+
+ goto retry;
}
- up_read(&mm->mmap_sem);
+ mmap_read_unlock(mm);
return;
/*
@@ -192,27 +189,31 @@ good_area:
* Fix it, but check if it's kernel or user first..
*/
bad_area:
- up_read(&mm->mmap_sem);
+ mmap_read_unlock(mm);
bad_area_nosemaphore:
/* User mode accesses just cause a SIGSEGV */
if (user_mode(regs)) {
tsk->thread.cp0_badvaddr = address;
tsk->thread.error_code = write;
-#if 0
- printk("do_page_fault() #2: sending SIGSEGV to %s for "
- "invalid %s\n%0*lx (epc == %0*lx, ra == %0*lx)\n",
- tsk->comm,
- write ? "write access to" : "read access from",
- field, address,
- field, (unsigned long) regs->cp0_epc,
- field, (unsigned long) regs->regs[31]);
-#endif
- info.si_signo = SIGSEGV;
- info.si_errno = 0;
- /* info.si_code has been set above */
- info.si_addr = (void __user *) address;
- force_sig_info(SIGSEGV, &info, tsk);
+ if (show_unhandled_signals &&
+ unhandled_signal(tsk, SIGSEGV) &&
+ __ratelimit(&ratelimit_state)) {
+ pr_info("do_page_fault(): sending SIGSEGV to %s for invalid %s %0*lx\n",
+ tsk->comm,
+ write ? "write access to" : "read access from",
+ field, address);
+ pr_info("epc = %0*lx in", field,
+ (unsigned long) regs->cp0_epc);
+ print_vma_addr(KERN_CONT " ", regs->cp0_epc);
+ pr_cont("\n");
+ pr_info("ra = %0*lx in", field,
+ (unsigned long) regs->regs[31]);
+ print_vma_addr(KERN_CONT " ", regs->regs[31]);
+ pr_cont("\n");
+ }
+ current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
+ force_sig_fault(SIGSEGV, si_code, (void __user *)address);
return;
}
@@ -240,36 +241,35 @@ out_of_memory:
* We ran out of memory, call the OOM killer, and return the userspace
* (which will retry the fault, or kill us if we got oom-killed).
*/
- up_read(&mm->mmap_sem);
+ mmap_read_unlock(mm);
+ if (!user_mode(regs))
+ goto no_context;
pagefault_out_of_memory();
return;
do_sigbus:
- up_read(&mm->mmap_sem);
+ mmap_read_unlock(mm);
/* Kernel mode? Handle exceptions or die */
if (!user_mode(regs))
goto no_context;
- else
+
/*
* Send a sigbus, regardless of whether we were in kernel
* or user mode.
*/
#if 0
- printk("do_page_fault() #3: sending SIGBUS to %s for "
- "invalid %s\n%0*lx (epc == %0*lx, ra == %0*lx)\n",
- tsk->comm,
- write ? "write access to" : "read access from",
- field, address,
- field, (unsigned long) regs->cp0_epc,
- field, (unsigned long) regs->regs[31]);
+ printk("do_page_fault() #3: sending SIGBUS to %s for "
+ "invalid %s\n%0*lx (epc == %0*lx, ra == %0*lx)\n",
+ tsk->comm,
+ write ? "write access to" : "read access from",
+ field, address,
+ field, (unsigned long) regs->cp0_epc,
+ field, (unsigned long) regs->regs[31]);
#endif
+ current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
tsk->thread.cp0_badvaddr = address;
- info.si_signo = SIGBUS;
- info.si_errno = 0;
- info.si_code = BUS_ADRERR;
- info.si_addr = (void __user *) address;
- force_sig_info(SIGBUS, &info, tsk);
+ force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address);
return;
#ifndef CONFIG_64BIT
@@ -282,8 +282,9 @@ vmalloc_fault:
* Do _not_ use "tsk" here. We might be inside
* an interrupt in the middle of a task switch..
*/
- int offset = __pgd_offset(address);
+ int offset = pgd_index(address);
pgd_t *pgd, *pgd_k;
+ p4d_t *p4d, *p4d_k;
pud_t *pud, *pud_k;
pmd_t *pmd, *pmd_k;
pte_t *pte_k;
@@ -295,8 +296,13 @@ vmalloc_fault:
goto no_context;
set_pgd(pgd, *pgd_k);
- pud = pud_offset(pgd, address);
- pud_k = pud_offset(pgd_k, address);
+ p4d = p4d_offset(pgd, address);
+ p4d_k = p4d_offset(pgd_k, address);
+ if (!p4d_present(*p4d_k))
+ goto no_context;
+
+ pud = pud_offset(p4d, address);
+ pud_k = pud_offset(p4d_k, address);
if (!pud_present(*pud_k))
goto no_context;
@@ -313,8 +319,9 @@ vmalloc_fault:
}
#endif
}
+NOKPROBE_SYMBOL(__do_page_fault);
-asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
+asmlinkage void do_page_fault(struct pt_regs *regs,
unsigned long write, unsigned long address)
{
enum ctx_state prev_state;
@@ -323,3 +330,4 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
__do_page_fault(regs, write, address);
exception_exit(prev_state);
}
+NOKPROBE_SYMBOL(do_page_fault);
generated by cgit (git 2.34.1) at 2025-12-21 21:12:00 +0000