59d5af6732
drop numbers and commit hashes from patch metadata to reduce future patch churn
364 lines
13 KiB
Diff
364 lines
13 KiB
Diff
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
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From: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
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Date: Fri, 27 Oct 2017 13:25:28 -0700
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Subject: [PATCH] x86/mm: Relocate page fault error codes to traps.h
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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CVE-2017-5754
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Up to this point, only fault.c used the definitions of the page fault error
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codes. Thus, it made sense to keep them within such file. Other portions of
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code might be interested in those definitions too. For instance, the User-
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Mode Instruction Prevention emulation code will use such definitions to
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emulate a page fault when it is unable to successfully copy the results
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of the emulated instructions to user space.
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While relocating the error code enumeration, the prefix X86_ is used to
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make it consistent with the rest of the definitions in traps.h. Of course,
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code using the enumeration had to be updated as well. No functional changes
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were performed.
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Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
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Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Reviewed-by: Borislav Petkov <bp@suse.de>
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Reviewed-by: Andy Lutomirski <luto@kernel.org>
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Cc: "Michael S. Tsirkin" <mst@redhat.com>
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Cc: Peter Zijlstra <peterz@infradead.org>
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Cc: Dave Hansen <dave.hansen@linux.intel.com>
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Cc: ricardo.neri@intel.com
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Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
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Cc: Huang Rui <ray.huang@amd.com>
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Cc: Shuah Khan <shuah@kernel.org>
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Cc: Jonathan Corbet <corbet@lwn.net>
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Cc: Jiri Slaby <jslaby@suse.cz>
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Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
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Cc: Chris Metcalf <cmetcalf@mellanox.com>
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Cc: Brian Gerst <brgerst@gmail.com>
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Cc: Josh Poimboeuf <jpoimboe@redhat.com>
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Cc: Chen Yucong <slaoub@gmail.com>
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Cc: Vlastimil Babka <vbabka@suse.cz>
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Cc: Masami Hiramatsu <mhiramat@kernel.org>
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Cc: Paolo Bonzini <pbonzini@redhat.com>
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Cc: Andrew Morton <akpm@linux-foundation.org>
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Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
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Link: https://lkml.kernel.org/r/1509135945-13762-2-git-send-email-ricardo.neri-calderon@linux.intel.com
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(cherry picked from commit 1067f030994c69ca1fba8c607437c8895dcf8509)
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Signed-off-by: Andy Whitcroft <apw@canonical.com>
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Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
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(cherry picked from commit a85a07ab9111e3c78797c20b60a664dbd5db4981)
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Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
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---
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arch/x86/include/asm/traps.h | 18 +++++++++
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arch/x86/mm/fault.c | 88 +++++++++++++++++---------------------------
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2 files changed, 52 insertions(+), 54 deletions(-)
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diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h
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index feb89dbe359d..8e5bf86f87e5 100644
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--- a/arch/x86/include/asm/traps.h
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+++ b/arch/x86/include/asm/traps.h
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@@ -162,4 +162,22 @@ enum {
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X86_TRAP_IRET = 32, /* 32, IRET Exception */
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};
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+/*
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+ * Page fault error code bits:
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+ *
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+ * bit 0 == 0: no page found 1: protection fault
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+ * bit 1 == 0: read access 1: write access
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+ * bit 2 == 0: kernel-mode access 1: user-mode access
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+ * bit 3 == 1: use of reserved bit detected
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+ * bit 4 == 1: fault was an instruction fetch
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+ * bit 5 == 1: protection keys block access
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+ */
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+enum x86_pf_error_code {
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+ X86_PF_PROT = 1 << 0,
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+ X86_PF_WRITE = 1 << 1,
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+ X86_PF_USER = 1 << 2,
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+ X86_PF_RSVD = 1 << 3,
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+ X86_PF_INSTR = 1 << 4,
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+ X86_PF_PK = 1 << 5,
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+};
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#endif /* _ASM_X86_TRAPS_H */
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diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
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index 4ee9eb916826..d3a57e7ad311 100644
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--- a/arch/x86/mm/fault.c
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+++ b/arch/x86/mm/fault.c
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@@ -28,26 +28,6 @@
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#define CREATE_TRACE_POINTS
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#include <asm/trace/exceptions.h>
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-/*
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- * Page fault error code bits:
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- *
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- * bit 0 == 0: no page found 1: protection fault
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- * bit 1 == 0: read access 1: write access
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- * bit 2 == 0: kernel-mode access 1: user-mode access
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- * bit 3 == 1: use of reserved bit detected
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- * bit 4 == 1: fault was an instruction fetch
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- * bit 5 == 1: protection keys block access
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- */
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-enum x86_pf_error_code {
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-
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- PF_PROT = 1 << 0,
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- PF_WRITE = 1 << 1,
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- PF_USER = 1 << 2,
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- PF_RSVD = 1 << 3,
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- PF_INSTR = 1 << 4,
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- PF_PK = 1 << 5,
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-};
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-
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/*
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* Returns 0 if mmiotrace is disabled, or if the fault is not
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* handled by mmiotrace:
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@@ -149,7 +129,7 @@ is_prefetch(struct pt_regs *regs, unsigned long error_code, unsigned long addr)
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* If it was a exec (instruction fetch) fault on NX page, then
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* do not ignore the fault:
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*/
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- if (error_code & PF_INSTR)
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+ if (error_code & X86_PF_INSTR)
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return 0;
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instr = (void *)convert_ip_to_linear(current, regs);
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@@ -179,7 +159,7 @@ is_prefetch(struct pt_regs *regs, unsigned long error_code, unsigned long addr)
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* siginfo so userspace can discover which protection key was set
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* on the PTE.
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*
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- * If we get here, we know that the hardware signaled a PF_PK
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+ * If we get here, we know that the hardware signaled a X86_PF_PK
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* fault and that there was a VMA once we got in the fault
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* handler. It does *not* guarantee that the VMA we find here
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* was the one that we faulted on.
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@@ -204,7 +184,7 @@ static void fill_sig_info_pkey(int si_code, siginfo_t *info, u32 *pkey)
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/*
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* force_sig_info_fault() is called from a number of
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* contexts, some of which have a VMA and some of which
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- * do not. The PF_PK handing happens after we have a
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+ * do not. The X86_PF_PK handing happens after we have a
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* valid VMA, so we should never reach this without a
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* valid VMA.
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*/
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@@ -693,7 +673,7 @@ show_fault_oops(struct pt_regs *regs, unsigned long error_code,
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if (!oops_may_print())
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return;
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- if (error_code & PF_INSTR) {
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+ if (error_code & X86_PF_INSTR) {
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unsigned int level;
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pgd_t *pgd;
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pte_t *pte;
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@@ -775,7 +755,7 @@ no_context(struct pt_regs *regs, unsigned long error_code,
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*/
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if (current->thread.sig_on_uaccess_err && signal) {
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tsk->thread.trap_nr = X86_TRAP_PF;
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- tsk->thread.error_code = error_code | PF_USER;
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+ tsk->thread.error_code = error_code | X86_PF_USER;
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tsk->thread.cr2 = address;
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/* XXX: hwpoison faults will set the wrong code. */
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@@ -894,7 +874,7 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
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struct task_struct *tsk = current;
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/* User mode accesses just cause a SIGSEGV */
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- if (error_code & PF_USER) {
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+ if (error_code & X86_PF_USER) {
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/*
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* It's possible to have interrupts off here:
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*/
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@@ -915,7 +895,7 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
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* Instruction fetch faults in the vsyscall page might need
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* emulation.
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*/
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- if (unlikely((error_code & PF_INSTR) &&
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+ if (unlikely((error_code & X86_PF_INSTR) &&
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((address & ~0xfff) == VSYSCALL_ADDR))) {
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if (emulate_vsyscall(regs, address))
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return;
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@@ -928,7 +908,7 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
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* are always protection faults.
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*/
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if (address >= TASK_SIZE_MAX)
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- error_code |= PF_PROT;
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+ error_code |= X86_PF_PROT;
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if (likely(show_unhandled_signals))
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show_signal_msg(regs, error_code, address, tsk);
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@@ -989,11 +969,11 @@ static inline bool bad_area_access_from_pkeys(unsigned long error_code,
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if (!boot_cpu_has(X86_FEATURE_OSPKE))
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return false;
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- if (error_code & PF_PK)
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+ if (error_code & X86_PF_PK)
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return true;
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/* this checks permission keys on the VMA: */
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- if (!arch_vma_access_permitted(vma, (error_code & PF_WRITE),
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- (error_code & PF_INSTR), foreign))
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+ if (!arch_vma_access_permitted(vma, (error_code & X86_PF_WRITE),
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+ (error_code & X86_PF_INSTR), foreign))
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return true;
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return false;
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}
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@@ -1021,7 +1001,7 @@ do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address,
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int code = BUS_ADRERR;
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/* Kernel mode? Handle exceptions or die: */
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- if (!(error_code & PF_USER)) {
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+ if (!(error_code & X86_PF_USER)) {
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no_context(regs, error_code, address, SIGBUS, BUS_ADRERR);
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return;
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}
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@@ -1049,14 +1029,14 @@ static noinline void
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mm_fault_error(struct pt_regs *regs, unsigned long error_code,
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unsigned long address, u32 *pkey, unsigned int fault)
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{
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- if (fatal_signal_pending(current) && !(error_code & PF_USER)) {
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+ if (fatal_signal_pending(current) && !(error_code & X86_PF_USER)) {
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no_context(regs, error_code, address, 0, 0);
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return;
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}
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if (fault & VM_FAULT_OOM) {
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/* Kernel mode? Handle exceptions or die: */
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- if (!(error_code & PF_USER)) {
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+ if (!(error_code & X86_PF_USER)) {
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no_context(regs, error_code, address,
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SIGSEGV, SEGV_MAPERR);
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return;
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@@ -1081,16 +1061,16 @@ mm_fault_error(struct pt_regs *regs, unsigned long error_code,
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static int spurious_fault_check(unsigned long error_code, pte_t *pte)
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{
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- if ((error_code & PF_WRITE) && !pte_write(*pte))
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+ if ((error_code & X86_PF_WRITE) && !pte_write(*pte))
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return 0;
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- if ((error_code & PF_INSTR) && !pte_exec(*pte))
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+ if ((error_code & X86_PF_INSTR) && !pte_exec(*pte))
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return 0;
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/*
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* Note: We do not do lazy flushing on protection key
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- * changes, so no spurious fault will ever set PF_PK.
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+ * changes, so no spurious fault will ever set X86_PF_PK.
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*/
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- if ((error_code & PF_PK))
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+ if ((error_code & X86_PF_PK))
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return 1;
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return 1;
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@@ -1136,8 +1116,8 @@ spurious_fault(unsigned long error_code, unsigned long address)
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* change, so user accesses are not expected to cause spurious
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* faults.
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*/
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- if (error_code != (PF_WRITE | PF_PROT)
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- && error_code != (PF_INSTR | PF_PROT))
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+ if (error_code != (X86_PF_WRITE | X86_PF_PROT) &&
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+ error_code != (X86_PF_INSTR | X86_PF_PROT))
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return 0;
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pgd = init_mm.pgd + pgd_index(address);
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@@ -1197,19 +1177,19 @@ access_error(unsigned long error_code, struct vm_area_struct *vma)
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* always an unconditional error and can never result in
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* a follow-up action to resolve the fault, like a COW.
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*/
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- if (error_code & PF_PK)
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+ if (error_code & X86_PF_PK)
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return 1;
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/*
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* Make sure to check the VMA so that we do not perform
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- * faults just to hit a PF_PK as soon as we fill in a
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+ * faults just to hit a X86_PF_PK as soon as we fill in a
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* page.
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*/
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- if (!arch_vma_access_permitted(vma, (error_code & PF_WRITE),
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- (error_code & PF_INSTR), foreign))
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+ if (!arch_vma_access_permitted(vma, (error_code & X86_PF_WRITE),
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+ (error_code & X86_PF_INSTR), foreign))
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return 1;
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- if (error_code & PF_WRITE) {
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+ if (error_code & X86_PF_WRITE) {
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/* write, present and write, not present: */
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if (unlikely(!(vma->vm_flags & VM_WRITE)))
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return 1;
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@@ -1217,7 +1197,7 @@ access_error(unsigned long error_code, struct vm_area_struct *vma)
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}
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/* read, present: */
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- if (unlikely(error_code & PF_PROT))
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+ if (unlikely(error_code & X86_PF_PROT))
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return 1;
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/* read, not present: */
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@@ -1240,7 +1220,7 @@ static inline bool smap_violation(int error_code, struct pt_regs *regs)
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if (!static_cpu_has(X86_FEATURE_SMAP))
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return false;
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- if (error_code & PF_USER)
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+ if (error_code & X86_PF_USER)
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return false;
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if (!user_mode(regs) && (regs->flags & X86_EFLAGS_AC))
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@@ -1293,7 +1273,7 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,
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* protection error (error_code & 9) == 0.
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*/
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if (unlikely(fault_in_kernel_space(address))) {
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- if (!(error_code & (PF_RSVD | PF_USER | PF_PROT))) {
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+ if (!(error_code & (X86_PF_RSVD | X86_PF_USER | X86_PF_PROT))) {
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if (vmalloc_fault(address) >= 0)
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return;
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@@ -1321,7 +1301,7 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,
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if (unlikely(kprobes_fault(regs)))
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return;
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- if (unlikely(error_code & PF_RSVD))
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+ if (unlikely(error_code & X86_PF_RSVD))
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pgtable_bad(regs, error_code, address);
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if (unlikely(smap_violation(error_code, regs))) {
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@@ -1347,7 +1327,7 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,
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*/
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if (user_mode(regs)) {
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local_irq_enable();
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- error_code |= PF_USER;
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+ error_code |= X86_PF_USER;
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flags |= FAULT_FLAG_USER;
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} else {
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if (regs->flags & X86_EFLAGS_IF)
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@@ -1356,9 +1336,9 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,
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perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
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- if (error_code & PF_WRITE)
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+ if (error_code & X86_PF_WRITE)
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flags |= FAULT_FLAG_WRITE;
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- if (error_code & PF_INSTR)
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+ if (error_code & X86_PF_INSTR)
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flags |= FAULT_FLAG_INSTRUCTION;
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/*
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@@ -1378,7 +1358,7 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,
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* space check, thus avoiding the deadlock:
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*/
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if (unlikely(!down_read_trylock(&mm->mmap_sem))) {
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- if ((error_code & PF_USER) == 0 &&
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+ if (!(error_code & X86_PF_USER) &&
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!search_exception_tables(regs->ip)) {
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bad_area_nosemaphore(regs, error_code, address, NULL);
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return;
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@@ -1405,7 +1385,7 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,
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bad_area(regs, error_code, address);
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return;
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}
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- if (error_code & PF_USER) {
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+ if (error_code & X86_PF_USER) {
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/*
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* Accessing the stack below %sp is always a bug.
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* The large cushion allows instructions like enter
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--
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2.14.2
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