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Message-Id: <201403072325.s27NPvlt003528@terminus.zytor.com>
Date: Fri, 7 Mar 2014 15:25:57 -0800
From: "H. Peter Anvin" <hpa@...ux.intel.com>
To: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: a.p.zijlstra@...llo.nl, acme@...stprotocols.net, bp@...e.de,
dzickus@...hat.com, hpa@...ux.intel.com, hpa@...or.com,
jolsa@...hat.com, linux-kernel@...r.kernel.org,
matt.fleming@...el.com, mingo@...nel.org, paulus@...ba.org,
peterz@...radead.org, rja@....com, rostedt@...dmis.org,
seiji.aguchi@....com, tglx@...utronix.de, vincent.weaver@...ne.edu
Subject: [GIT PULL] x86 fixes for v3.14-rc6
Hi Linus,
A small collection of minor fixes. The FPU stuff is still pending, I
fear. I haven't heard anything from Suresh so I suspect I'm going to
have to dig into the init specifics myself and fix up the patchset.
The following changes since commit 0414855fdc4a40da05221fc6062cccbc0c30f169:
Linux 3.14-rc5 (2014-03-02 18:56:16 -0800)
are available in the git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-urgent-for-linus
for you to fetch changes up to 5fa10196bdb5f190f595ebd048490ee52dddea0f:
x86: Ignore NMIs that come in during early boot (2014-03-07 15:08:14 -0800)
----------------------------------------------------------------
Borislav Petkov (1):
x86/efi: Quirk out SGI UV
H. Peter Anvin (2):
Merge tag 'efi-urgent' into x86/urgent
x86: Ignore NMIs that come in during early boot
Jiri Olsa (1):
x86, trace: Fix CR2 corruption when tracing page faults
Peter Zijlstra (1):
x86, trace: Further robustify CR2 handling vs tracing
arch/x86/include/asm/efi.h | 1 +
arch/x86/kernel/head_32.S | 7 ++++++-
arch/x86/kernel/head_64.S | 6 +++++-
arch/x86/kernel/setup.c | 10 ++--------
arch/x86/mm/fault.c | 47 +++++++++++++++++++++++++++++++--------------
arch/x86/platform/efi/efi.c | 20 +++++++++++++++++++
6 files changed, 67 insertions(+), 24 deletions(-)
diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index 3d6b9f8..acd86c8 100644
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -134,6 +134,7 @@ extern void efi_setup_page_tables(void);
extern void __init old_map_region(efi_memory_desc_t *md);
extern void __init runtime_code_page_mkexec(void);
extern void __init efi_runtime_mkexec(void);
+extern void __init efi_apply_memmap_quirks(void);
struct efi_setup_data {
u64 fw_vendor;
diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index 81ba276..d2a2159 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -544,6 +544,10 @@ ENDPROC(early_idt_handlers)
/* This is global to keep gas from relaxing the jumps */
ENTRY(early_idt_handler)
cld
+
+ cmpl $X86_TRAP_NMI,(%esp)
+ je is_nmi # Ignore NMI
+
cmpl $2,%ss:early_recursion_flag
je hlt_loop
incl %ss:early_recursion_flag
@@ -594,8 +598,9 @@ ex_entry:
pop %edx
pop %ecx
pop %eax
- addl $8,%esp /* drop vector number and error code */
decl %ss:early_recursion_flag
+is_nmi:
+ addl $8,%esp /* drop vector number and error code */
iret
ENDPROC(early_idt_handler)
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index e1aabdb..33f36c7 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -343,6 +343,9 @@ early_idt_handlers:
ENTRY(early_idt_handler)
cld
+ cmpl $X86_TRAP_NMI,(%rsp)
+ je is_nmi # Ignore NMI
+
cmpl $2,early_recursion_flag(%rip)
jz 1f
incl early_recursion_flag(%rip)
@@ -405,8 +408,9 @@ ENTRY(early_idt_handler)
popq %rdx
popq %rcx
popq %rax
- addq $16,%rsp # drop vector number and error code
decl early_recursion_flag(%rip)
+is_nmi:
+ addq $16,%rsp # drop vector number and error code
INTERRUPT_RETURN
ENDPROC(early_idt_handler)
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 06853e6..ce72964 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1239,14 +1239,8 @@ void __init setup_arch(char **cmdline_p)
register_refined_jiffies(CLOCK_TICK_RATE);
#ifdef CONFIG_EFI
- /* Once setup is done above, unmap the EFI memory map on
- * mismatched firmware/kernel archtectures since there is no
- * support for runtime services.
- */
- if (efi_enabled(EFI_BOOT) && !efi_is_native()) {
- pr_info("efi: Setup done, disabling due to 32/64-bit mismatch\n");
- efi_unmap_memmap();
- }
+ if (efi_enabled(EFI_BOOT))
+ efi_apply_memmap_quirks();
#endif
}
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 6dea040..a10c8c7 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -1020,13 +1020,17 @@ static inline bool smap_violation(int error_code, struct pt_regs *regs)
* This routine handles page faults. It determines the address,
* and the problem, and then passes it off to one of the appropriate
* routines.
+ *
+ * This function must have noinline because both callers
+ * {,trace_}do_page_fault() have notrace on. Having this an actual function
+ * guarantees there's a function trace entry.
*/
-static void __kprobes
-__do_page_fault(struct pt_regs *regs, unsigned long error_code)
+static void __kprobes noinline
+__do_page_fault(struct pt_regs *regs, unsigned long error_code,
+ unsigned long address)
{
struct vm_area_struct *vma;
struct task_struct *tsk;
- unsigned long address;
struct mm_struct *mm;
int fault;
unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
@@ -1034,9 +1038,6 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code)
tsk = current;
mm = tsk->mm;
- /* Get the faulting address: */
- address = read_cr2();
-
/*
* Detect and handle instructions that would cause a page fault for
* both a tracked kernel page and a userspace page.
@@ -1248,32 +1249,50 @@ good_area:
up_read(&mm->mmap_sem);
}
-dotraplinkage void __kprobes
+dotraplinkage void __kprobes notrace
do_page_fault(struct pt_regs *regs, unsigned long error_code)
{
+ unsigned long address = read_cr2(); /* Get the faulting address */
enum ctx_state prev_state;
+ /*
+ * We must have this function tagged with __kprobes, notrace and call
+ * read_cr2() before calling anything else. To avoid calling any kind
+ * of tracing machinery before we've observed the CR2 value.
+ *
+ * exception_{enter,exit}() contain all sorts of tracepoints.
+ */
+
prev_state = exception_enter();
- __do_page_fault(regs, error_code);
+ __do_page_fault(regs, error_code, address);
exception_exit(prev_state);
}
-static void trace_page_fault_entries(struct pt_regs *regs,
+#ifdef CONFIG_TRACING
+static void trace_page_fault_entries(unsigned long address, struct pt_regs *regs,
unsigned long error_code)
{
if (user_mode(regs))
- trace_page_fault_user(read_cr2(), regs, error_code);
+ trace_page_fault_user(address, regs, error_code);
else
- trace_page_fault_kernel(read_cr2(), regs, error_code);
+ trace_page_fault_kernel(address, regs, error_code);
}
-dotraplinkage void __kprobes
+dotraplinkage void __kprobes notrace
trace_do_page_fault(struct pt_regs *regs, unsigned long error_code)
{
+ /*
+ * The exception_enter and tracepoint processing could
+ * trigger another page faults (user space callchain
+ * reading) and destroy the original cr2 value, so read
+ * the faulting address now.
+ */
+ unsigned long address = read_cr2();
enum ctx_state prev_state;
prev_state = exception_enter();
- trace_page_fault_entries(regs, error_code);
- __do_page_fault(regs, error_code);
+ trace_page_fault_entries(address, regs, error_code);
+ __do_page_fault(regs, error_code, address);
exception_exit(prev_state);
}
+#endif /* CONFIG_TRACING */
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 1a201ac..b97acec 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -52,6 +52,7 @@
#include <asm/tlbflush.h>
#include <asm/x86_init.h>
#include <asm/rtc.h>
+#include <asm/uv/uv.h>
#define EFI_DEBUG
@@ -1210,3 +1211,22 @@ static int __init parse_efi_cmdline(char *str)
return 0;
}
early_param("efi", parse_efi_cmdline);
+
+void __init efi_apply_memmap_quirks(void)
+{
+ /*
+ * Once setup is done earlier, unmap the EFI memory map on mismatched
+ * firmware/kernel architectures since there is no support for runtime
+ * services.
+ */
+ if (!efi_is_native()) {
+ pr_info("efi: Setup done, disabling due to 32/64-bit mismatch\n");
+ efi_unmap_memmap();
+ }
+
+ /*
+ * UV doesn't support the new EFI pagetable mapping yet.
+ */
+ if (is_uv_system())
+ set_bit(EFI_OLD_MEMMAP, &x86_efi_facility);
+}
--
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