thr3ads.net - Xen devel - [PATCH v2 0/6] Collected vdso/vsyscall fixes for 3.1 [Aug 2011]

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Andy Lutomirski

2011-Aug-03 13:31 UTC

[PATCH v2 0/6] Collected vdso/vsyscall fixes for 3.1

This fixes various problems that cropped up with the vdso patches.

 - Patch 1 fixes an information leak to userspace.
 - Patches 2 and 3 fix the kernel build on gold.
 - Patches 4 and 5 fix Xen (I hope).
 - Patch 6 (optional) adds a trace event to vsyscall emulation.  It will
   make it easier to handle performance regression reports :)

[1] https://gitorious.org/linux-test-utils/linux-clock-tests

Changes from v1:
 - Improve changelog message for "x86-64/xen: Enable the vvar mapping"
 - Fix 32-bit build.
 - Add patch 6.

Andy Lutomirski (6):
  x86-64: Pad vDSO to a page boundary
  x86-64: Move the "user" vsyscall segment out of the data segment.
  x86-64: Work around gold bug 13023
  x86-64/xen: Enable the vvar mapping
  x86-64: Add user_64bit_mode paravirt op
  x86-64: Add vsyscall:emulate_vsyscall trace event

 arch/x86/include/asm/desc.h           |    4 +-
 arch/x86/include/asm/paravirt_types.h |    6 ++++
 arch/x86/include/asm/ptrace.h         |   19 +++++++++++++
 arch/x86/kernel/paravirt.c            |    4 +++
 arch/x86/kernel/step.c                |    2 +-
 arch/x86/kernel/vmlinux.lds.S         |   46 ++++++++++++++++++---------------
 arch/x86/kernel/vsyscall_64.c         |   12 +++++---
 arch/x86/kernel/vsyscall_trace.h      |   29 ++++++++++++++++++++
 arch/x86/mm/fault.c                   |    2 +-
 arch/x86/vdso/vdso.S                  |    1 +
 arch/x86/xen/enlighten.c              |    4 +++
 arch/x86/xen/mmu.c                    |    4 ++-
 12 files changed, 102 insertions(+), 31 deletions(-)
 create mode 100644 arch/x86/kernel/vsyscall_trace.h

-- 
1.7.6

Andy Lutomirski

2011-Aug-03 13:31 UTC

head link

[PATCH v2 1/6] x86-64: Pad vDSO to a page boundary

This avoids an information leak to userspace.

Signed-off-by: Andy Lutomirski <luto at mit.edu>
---
 arch/x86/vdso/vdso.S |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/arch/x86/vdso/vdso.S b/arch/x86/vdso/vdso.S
index 1b979c1..01f5e3b 100644
--- a/arch/x86/vdso/vdso.S
+++ b/arch/x86/vdso/vdso.S
@@ -9,6 +9,7 @@ __PAGE_ALIGNED_DATA
 vdso_start:
 	.incbin "arch/x86/vdso/vdso.so"
 vdso_end:
+	.align PAGE_SIZE /* extra data here leaks to userspace. */
 
 .previous
 
-- 
1.7.6

Andy Lutomirski

2011-Aug-03 13:31 UTC

head link

[PATCH v2 2/6] x86-64: Move the "user" vsyscall segment out of the data segment.

The kernel's loader doesn't seem to care, but gold complains.

Signed-off-by: Andy Lutomirski <luto at mit.edu>
Reported-by: Arkadiusz Miskiewicz <a.miskiewicz at gmail.com>
---
 arch/x86/kernel/vmlinux.lds.S |   36 ++++++++++++++++++------------------
 1 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index 4aa9c54..e79fb39 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -154,6 +154,24 @@ SECTIONS
 
 #ifdef CONFIG_X86_64
 
+	. = ALIGN(PAGE_SIZE);
+	__vvar_page = .;
+
+	.vvar : AT(ADDR(.vvar) - LOAD_OFFSET) {
+
+	      /* Place all vvars at the offsets in asm/vvar.h. */
+#define EMIT_VVAR(name, offset) 		\
+		. = offset;		\
+		*(.vvar_ ## name)
+#define __VVAR_KERNEL_LDS
+#include <asm/vvar.h>
+#undef __VVAR_KERNEL_LDS
+#undef EMIT_VVAR
+
+	} :data
+
+       . = ALIGN(__vvar_page + PAGE_SIZE, PAGE_SIZE);
+
 #define VSYSCALL_ADDR (-10*1024*1024)
 
 #define VLOAD_OFFSET (VSYSCALL_ADDR - __vsyscall_0 + LOAD_OFFSET)
@@ -162,7 +180,6 @@ SECTIONS
 #define VVIRT_OFFSET (VSYSCALL_ADDR - __vsyscall_0)
 #define VVIRT(x) (ADDR(x) - VVIRT_OFFSET)
 
-	. = ALIGN(4096);
 	__vsyscall_0 = .;
 
 	. = VSYSCALL_ADDR;
@@ -185,23 +202,6 @@ SECTIONS
 #undef VVIRT_OFFSET
 #undef VVIRT
 
-	__vvar_page = .;
-
-	.vvar : AT(ADDR(.vvar) - LOAD_OFFSET) {
-
-	      /* Place all vvars at the offsets in asm/vvar.h. */
-#define EMIT_VVAR(name, offset) 		\
-		. = offset;		\
-		*(.vvar_ ## name)
-#define __VVAR_KERNEL_LDS
-#include <asm/vvar.h>
-#undef __VVAR_KERNEL_LDS
-#undef EMIT_VVAR
-
-	} :data
-
-       . = ALIGN(__vvar_page + PAGE_SIZE, PAGE_SIZE);
-
 #endif /* CONFIG_X86_64 */
 
 	/* Init code and data - will be freed after init */
-- 
1.7.6

Andy Lutomirski

2011-Aug-03 13:31 UTC

head link

[PATCH v2 3/6] x86-64: Work around gold bug 13023

Gold has trouble assigning numbers to the location counter inside of
an output section description.  The bug was triggered by
9fd67b4ed0714ab718f1f9bd14c344af336a6df7, which consolidated all of
the vsyscall sections into a single section.  The workaround is IMO
still nicer than the old way of doing it.

This produces an apparently valid kernel image and passes my vdso
tests on both GNU ld version 2.21.51.0.6-2.fc15 20110118 and GNU
gold (version 2.21.51.0.6-2.fc15 20110118) 1.10 as distributed by
Fedora 15.

Signed-off-by: Andy Lutomirski <luto at mit.edu>
Reported-by: Arkadiusz Miskiewicz <a.miskiewicz at gmail.com>
---
 arch/x86/kernel/vmlinux.lds.S |   16 ++++++++++------
 1 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index e79fb39..8f3a265 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -158,10 +158,12 @@ SECTIONS
 	__vvar_page = .;
 
 	.vvar : AT(ADDR(.vvar) - LOAD_OFFSET) {
+		/* work around gold bug 13023 */
+		__vvar_beginning_hack = .;
 
-	      /* Place all vvars at the offsets in asm/vvar.h. */
-#define EMIT_VVAR(name, offset) 		\
-		. = offset;		\
+		/* Place all vvars at the offsets in asm/vvar.h. */
+#define EMIT_VVAR(name, offset) 			\
+		. = __vvar_beginning_hack + offset;	\
 		*(.vvar_ ## name)
 #define __VVAR_KERNEL_LDS
 #include <asm/vvar.h>
@@ -184,15 +186,17 @@ SECTIONS
 
 	. = VSYSCALL_ADDR;
 	.vsyscall : AT(VLOAD(.vsyscall)) {
+		/* work around gold bug 13023 */
+		__vsyscall_beginning_hack = .;
 		*(.vsyscall_0)
 
-		. = 1024;
+		. = __vsyscall_beginning_hack + 1024;
 		*(.vsyscall_1)
 
-		. = 2048;
+		. = __vsyscall_beginning_hack + 2048;
 		*(.vsyscall_2)
 
-		. = 4096;  /* Pad the whole page. */
+		. = __vsyscall_beginning_hack + 4096;  /* Pad the whole page. */
 	} :user =0xcc
 	. = ALIGN(__vsyscall_0 + PAGE_SIZE, PAGE_SIZE);
 
-- 
1.7.6

Andy Lutomirski

2011-Aug-03 13:31 UTC

head link

[PATCH v2 4/6] x86-64/xen: Enable the vvar mapping

Xen needs to handle VVAR_PAGE, introduced in git commit:
9fd67b4ed0714ab718f1f9bd14c344af336a6df7
x86-64: Give vvars their own page

Otherwise we die during bootup with a message like:

(XEN) mm.c:940:d10 Error getting mfn 1888 (pfn 1e3e48) from L1 entry
      8000000001888465 for l1e_owner=10, pg_owner=10
(XEN) mm.c:5049:d10 ptwr_emulate: could not get_page_from_l1e()
[    0.000000] BUG: unable to handle kernel NULL pointer dereference at (null)
[    0.000000] IP: [<ffffffff8103a930>] xen_set_pte+0x20/0xe0

Signed-off-by: Andy Lutomirski <luto at mit.edu>
Reported-by: Konrad Rzeszutek Wilk <konrad.wilk at oracle.com>
---
 arch/x86/xen/mmu.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index f987bde..8cce339 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -1916,6 +1916,7 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t phys,
pgprot_t prot)
 # endif
 #else
 	case VSYSCALL_LAST_PAGE ... VSYSCALL_FIRST_PAGE:
+	case VVAR_PAGE:
 #endif
 	case FIX_TEXT_POKE0:
 	case FIX_TEXT_POKE1:
@@ -1956,7 +1957,8 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t phys,
pgprot_t prot)
 #ifdef CONFIG_X86_64
 	/* Replicate changes to map the vsyscall page into the user
 	   pagetable vsyscall mapping. */
-	if (idx >= VSYSCALL_LAST_PAGE && idx <= VSYSCALL_FIRST_PAGE) {
+	if ((idx >= VSYSCALL_LAST_PAGE && idx <= VSYSCALL_FIRST_PAGE) ||
+	    idx == VVAR_PAGE) {
 		unsigned long vaddr = __fix_to_virt(idx);
 		set_pte_vaddr_pud(level3_user_vsyscall, vaddr, pte);
 	}
-- 
1.7.6

Andy Lutomirski

2011-Aug-03 13:31 UTC

head link

[PATCH v2 5/6] x86-64: Add user_64bit_mode paravirt op

Three places in the kernel assume that the only long mode CPL 3
selector is __USER_CS.  This is not true on Xen -- Xen's sysretq
changes cs to the magic value 0xe033.

Two of the places are corner cases, but as of "x86-64: Improve
vsyscall emulation CS and RIP handling"
(c9712944b2a12373cb6ff8059afcfb7e826a6c54), vsyscalls will segfault
if called with Xen's extra CS selector.  This causes a panic when
older init builds die.

It seems impossible to make Xen use __USER_CS reliably without
taking a performance hit on every system call, so this fixes the
tests instead with a new paravirt op.  It's a little ugly because
ptrace.h can't include paravirt.h.

Signed-off-by: Andy Lutomirski <luto at mit.edu>
Reported-by: Konrad Rzeszutek Wilk <konrad.wilk at oracle.com>
---
 arch/x86/include/asm/desc.h           |    4 ++--
 arch/x86/include/asm/paravirt_types.h |    6 ++++++
 arch/x86/include/asm/ptrace.h         |   19 +++++++++++++++++++
 arch/x86/kernel/paravirt.c            |    4 ++++
 arch/x86/kernel/step.c                |    2 +-
 arch/x86/kernel/vsyscall_64.c         |    6 +-----
 arch/x86/mm/fault.c                   |    2 +-
 arch/x86/xen/enlighten.c              |    4 ++++
 8 files changed, 38 insertions(+), 9 deletions(-)

diff --git a/arch/x86/include/asm/desc.h b/arch/x86/include/asm/desc.h
index 7b439d9..41935fa 100644
--- a/arch/x86/include/asm/desc.h
+++ b/arch/x86/include/asm/desc.h
@@ -27,8 +27,8 @@ static inline void fill_ldt(struct desc_struct *desc, const
struct user_desc *in
 
 	desc->base2		= (info->base_addr & 0xff000000) >> 24;
 	/*
-	 * Don't allow setting of the lm bit. It is useless anyway
-	 * because 64bit system calls require __USER_CS:
+	 * Don't allow setting of the lm bit. It would confuse
+	 * user_64bit_mode and would get overridden by sysret anyway.
 	 */
 	desc->l			= 0;
 }
diff --git a/arch/x86/include/asm/paravirt_types.h
b/arch/x86/include/asm/paravirt_types.h
index 2c76521..8e8b9a4 100644
--- a/arch/x86/include/asm/paravirt_types.h
+++ b/arch/x86/include/asm/paravirt_types.h
@@ -41,6 +41,7 @@
 
 #include <asm/desc_defs.h>
 #include <asm/kmap_types.h>
+#include <asm/pgtable_types.h>
 
 struct page;
 struct thread_struct;
@@ -63,6 +64,11 @@ struct paravirt_callee_save {
 struct pv_info {
 	unsigned int kernel_rpl;
 	int shared_kernel_pmd;
+
+#ifdef CONFIG_X86_64
+	u16 extra_user_64bit_cs;  /* __USER_CS if none */
+#endif
+
 	int paravirt_enabled;
 	const char *name;
 };
diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h
index 94e7618..3566454 100644
--- a/arch/x86/include/asm/ptrace.h
+++ b/arch/x86/include/asm/ptrace.h
@@ -131,6 +131,9 @@ struct pt_regs {
 #ifdef __KERNEL__
 
 #include <linux/init.h>
+#ifdef CONFIG_PARAVIRT
+#include <asm/paravirt_types.h>
+#endif
 
 struct cpuinfo_x86;
 struct task_struct;
@@ -187,6 +190,22 @@ static inline int v8086_mode(struct pt_regs *regs)
 #endif
 }
 
+#ifdef CONFIG_X86_64
+static inline bool user_64bit_mode(struct pt_regs *regs)
+{
+#ifndef CONFIG_PARAVIRT
+	/*
+	 * On non-paravirt systems, this is the only long mode CPL 3
+	 * selector.  We do not allow long mode selectors in the LDT.
+	 */
+	return regs->cs == __USER_CS;
+#else
+	/* Headers are too twisted for this to go in paravirt.h. */
+	return regs->cs == __USER_CS || regs->cs == pv_info.extra_user_64bit_cs;
+#endif
+}
+#endif
+
 /*
  * X86_32 CPUs don't save ss and esp if the CPU is already in kernel mode
  * when it traps.  The previous stack will be directly underneath the saved
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index 613a793..d90272e 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -307,6 +307,10 @@ struct pv_info pv_info = {
 	.paravirt_enabled = 0,
 	.kernel_rpl = 0,
 	.shared_kernel_pmd = 1,	/* Only used when CONFIG_X86_PAE is set */
+
+#ifdef CONFIG_X86_64
+	.extra_user_64bit_cs = __USER_CS,
+#endif
 };
 
 struct pv_init_ops pv_init_ops = {
diff --git a/arch/x86/kernel/step.c b/arch/x86/kernel/step.c
index 7977f0c..c346d11 100644
--- a/arch/x86/kernel/step.c
+++ b/arch/x86/kernel/step.c
@@ -74,7 +74,7 @@ static int is_setting_trap_flag(struct task_struct *child,
struct pt_regs *regs)
 
 #ifdef CONFIG_X86_64
 		case 0x40 ... 0x4f:
-			if (regs->cs != __USER_CS)
+			if (!user_64bit_mode(regs))
 				/* 32-bit mode: register increment */
 				return 0;
 			/* 64-bit mode: REX prefix */
diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c
index dda7dff..1725930 100644
--- a/arch/x86/kernel/vsyscall_64.c
+++ b/arch/x86/kernel/vsyscall_64.c
@@ -127,11 +127,7 @@ void dotraplinkage do_emulate_vsyscall(struct pt_regs
*regs, long error_code)
 
 	local_irq_enable();
 
-	/*
-	 * Real 64-bit user mode code has cs == __USER_CS.  Anything else
-	 * is bogus.
-	 */
-	if (regs->cs != __USER_CS) {
+	if (!user_64bit_mode(regs)) {
 		/*
 		 * If we trapped from kernel mode, we might as well OOPS now
 		 * instead of returning to some random address and OOPSing
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 4d09df0..decd51a 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -105,7 +105,7 @@ check_prefetch_opcode(struct pt_regs *regs, unsigned char
*instr,
 		 * but for now it's good enough to assume that long
 		 * mode only uses well known segments or kernel.
 		 */
-		return (!user_mode(regs)) || (regs->cs == __USER_CS);
+		return (!user_mode(regs) || user_64bit_mode(regs));
 #endif
 	case 0x60:
 		/* 0x64 thru 0x67 are valid prefixes in all modes. */
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 974a528..e2345af 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -951,6 +951,10 @@ static const struct pv_info xen_info __initconst = {
 	.paravirt_enabled = 1,
 	.shared_kernel_pmd = 0,
 
+#ifdef CONFIG_X86_64
+	.extra_user_64bit_cs = FLAT_USER_CS64,
+#endif
+
 	.name = "Xen",
 };
 
-- 
1.7.6

Andy Lutomirski

2011-Aug-03 13:31 UTC

head link

[PATCH v2 6/6] x86-64: Add vsyscall:emulate_vsyscall trace event

Vsyscall emulation is slow, so make it easy to track down.

Signed-off-by: Andy Lutomirski <luto at mit.edu>
---
 arch/x86/kernel/vsyscall_64.c    |    6 ++++++
 arch/x86/kernel/vsyscall_trace.h |   29 +++++++++++++++++++++++++++++
 2 files changed, 35 insertions(+), 0 deletions(-)
 create mode 100644 arch/x86/kernel/vsyscall_trace.h

diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c
index 1725930..93a0d46 100644
--- a/arch/x86/kernel/vsyscall_64.c
+++ b/arch/x86/kernel/vsyscall_64.c
@@ -50,6 +50,9 @@
 #include <asm/vgtod.h>
 #include <asm/traps.h>
 
+#define CREATE_TRACE_POINTS
+#include "vsyscall_trace.h"
+
 DEFINE_VVAR(int, vgetcpu_mode);
 DEFINE_VVAR(struct vsyscall_gtod_data, vsyscall_gtod_data)  {
@@ -146,6 +149,9 @@ void dotraplinkage do_emulate_vsyscall(struct pt_regs *regs,
long error_code)
 	 * and int 0xcc is two bytes long.
 	 */
 	vsyscall_nr = addr_to_vsyscall_nr(regs->ip - 2);
+
+	trace_emulate_vsyscall(vsyscall_nr);
+
 	if (vsyscall_nr < 0) {
 		warn_bad_vsyscall(KERN_WARNING, regs,
 				  "illegal int 0xcc (exploit attempt?)");
diff --git a/arch/x86/kernel/vsyscall_trace.h b/arch/x86/kernel/vsyscall_trace.h
new file mode 100644
index 0000000..a8b2ede
--- /dev/null
+++ b/arch/x86/kernel/vsyscall_trace.h
@@ -0,0 +1,29 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM vsyscall
+
+#if !defined(__VSYSCALL_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define __VSYSCALL_TRACE_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(emulate_vsyscall,
+
+	    TP_PROTO(int nr),
+
+	    TP_ARGS(nr),
+
+	    TP_STRUCT__entry(__field(int, nr)),
+
+	    TP_fast_assign(
+			   __entry->nr = nr;
+			   ),
+
+	    TP_printk("nr = %d", __entry->nr)
+);
+
+#endif
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH ../../arch/x86/kernel
+#define TRACE_INCLUDE_FILE vsyscall_trace
+#include <trace/define_trace.h>
-- 
1.7.6

Konrad Rzeszutek Wilk

2011-Aug-03 13:49 UTC

head link

[PATCH v2 4/6] x86-64/xen: Enable the vvar mapping

On Wed, Aug 03, 2011 at 09:31:52AM -0400, Andy Lutomirski
wrote:> Xen needs to handle VVAR_PAGE, introduced in git commit:
> 9fd67b4ed0714ab718f1f9bd14c344af336a6df7
> x86-64: Give vvars their own page
> 
> Otherwise we die during bootup with a message like:
> 
> (XEN) mm.c:940:d10 Error getting mfn 1888 (pfn 1e3e48) from L1 entry
>       8000000001888465 for l1e_owner=10, pg_owner=10
> (XEN) mm.c:5049:d10 ptwr_emulate: could not get_page_from_l1e()
> [    0.000000] BUG: unable to handle kernel NULL pointer dereference at
(null)
> [    0.000000] IP: [<ffffffff8103a930>] xen_set_pte+0x20/0xe0
> 
> Signed-off-by: Andy Lutomirski <luto at mit.edu>
> Reported-by: Konrad Rzeszutek Wilk <konrad.wilk at oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk at
oracle.com>> ---
>  arch/x86/xen/mmu.c |    4 +++-
>  1 files changed, 3 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
> index f987bde..8cce339 100644
> --- a/arch/x86/xen/mmu.c
> +++ b/arch/x86/xen/mmu.c
> @@ -1916,6 +1916,7 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t
phys, pgprot_t prot)
>  # endif
>  #else
>  	case VSYSCALL_LAST_PAGE ... VSYSCALL_FIRST_PAGE:
> +	case VVAR_PAGE:
>  #endif
>  	case FIX_TEXT_POKE0:
>  	case FIX_TEXT_POKE1:
> @@ -1956,7 +1957,8 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t
phys, pgprot_t prot)
>  #ifdef CONFIG_X86_64
>  	/* Replicate changes to map the vsyscall page into the user
>  	   pagetable vsyscall mapping. */
> -	if (idx >= VSYSCALL_LAST_PAGE && idx <=
VSYSCALL_FIRST_PAGE) {
> +	if ((idx >= VSYSCALL_LAST_PAGE && idx <=
VSYSCALL_FIRST_PAGE) ||
> +	    idx == VVAR_PAGE) {
>  		unsigned long vaddr = __fix_to_virt(idx);
>  		set_pte_vaddr_pud(level3_user_vsyscall, vaddr, pte);
>  	}
> -- 
> 1.7.6

Konrad Rzeszutek Wilk

2011-Aug-03 13:53 UTC

head link

[PATCH v2 0/6] Collected vdso/vsyscall fixes for 3.1

On Wed, Aug 03, 2011 at 09:31:48AM -0400, Andy Lutomirski
wrote:> This fixes various problems that cropped up with the vdso patches.
> 
>  - Patch 1 fixes an information leak to userspace.
>  - Patches 2 and 3 fix the kernel build on gold.
>  - Patches 4 and 5 fix Xen (I hope).
>  - Patch 6 (optional) adds a trace event to vsyscall emulation.  It will
>    make it easier to handle performance regression reports :)
Hm, you seemed to have the x86 maintainers on your
email..> 
> [1] https://gitorious.org/linux-test-utils/linux-clock-tests
> 
> Changes from v1:
>  - Improve changelog message for "x86-64/xen: Enable the vvar
mapping"
>  - Fix 32-bit build.
>  - Add patch 6.
> 
> Andy Lutomirski (6):
>   x86-64: Pad vDSO to a page boundary
>   x86-64: Move the "user" vsyscall segment out of the data
segment.
>   x86-64: Work around gold bug 13023
>   x86-64/xen: Enable the vvar mapping
>   x86-64: Add user_64bit_mode paravirt op
>   x86-64: Add vsyscall:emulate_vsyscall trace event
> 
>  arch/x86/include/asm/desc.h           |    4 +-
>  arch/x86/include/asm/paravirt_types.h |    6 ++++
>  arch/x86/include/asm/ptrace.h         |   19 +++++++++++++
>  arch/x86/kernel/paravirt.c            |    4 +++
>  arch/x86/kernel/step.c                |    2 +-
>  arch/x86/kernel/vmlinux.lds.S         |   46
++++++++++++++++++---------------
>  arch/x86/kernel/vsyscall_64.c         |   12 +++++---
>  arch/x86/kernel/vsyscall_trace.h      |   29 ++++++++++++++++++++
>  arch/x86/mm/fault.c                   |    2 +-
>  arch/x86/vdso/vdso.S                  |    1 +
>  arch/x86/xen/enlighten.c              |    4 +++
>  arch/x86/xen/mmu.c                    |    4 ++-
>  12 files changed, 102 insertions(+), 31 deletions(-)
>  create mode 100644 arch/x86/kernel/vsyscall_trace.h
> 
> -- 
> 1.7.6

Konrad Rzeszutek Wilk

2011-Aug-03 13:56 UTC

head link

[PATCH v2 0/6] Collected vdso/vsyscall fixes for 3.1

On Wed, Aug 03, 2011 at 09:53:22AM -0400, Konrad Rzeszutek Wilk
wrote:> On Wed, Aug 03, 2011 at 09:31:48AM -0400, Andy Lutomirski wrote:
> > This fixes various problems that cropped up with the vdso patches.
> > 
> >  - Patch 1 fixes an information leak to userspace.
> >  - Patches 2 and 3 fix the kernel build on gold.
> >  - Patches 4 and 5 fix Xen (I hope).
> >  - Patch 6 (optional) adds a trace event to vsyscall emulation.  It
will
> >    make it easier to handle performance regression reports :)
> 
> Hm, you seemed to have the x86 maintainers on your email..
I definitly need some coffee. What I meant was that you missing putting
the x86 maintainers on this patchset. They are the ones that will handle this.

I put them on the To list for you.> > 
> > [1] https://gitorious.org/linux-test-utils/linux-clock-tests
> > 
> > Changes from v1:
> >  - Improve changelog message for "x86-64/xen: Enable the vvar
mapping"
> >  - Fix 32-bit build.
> >  - Add patch 6.
> > 
> > Andy Lutomirski (6):
> >   x86-64: Pad vDSO to a page boundary
> >   x86-64: Move the "user" vsyscall segment out of the data
segment.
> >   x86-64: Work around gold bug 13023
> >   x86-64/xen: Enable the vvar mapping
> >   x86-64: Add user_64bit_mode paravirt op
> >   x86-64: Add vsyscall:emulate_vsyscall trace event
> > 
> >  arch/x86/include/asm/desc.h           |    4 +-
> >  arch/x86/include/asm/paravirt_types.h |    6 ++++
> >  arch/x86/include/asm/ptrace.h         |   19 +++++++++++++
> >  arch/x86/kernel/paravirt.c            |    4 +++
> >  arch/x86/kernel/step.c                |    2 +-
> >  arch/x86/kernel/vmlinux.lds.S         |   46
++++++++++++++++++---------------
> >  arch/x86/kernel/vsyscall_64.c         |   12 +++++---
> >  arch/x86/kernel/vsyscall_trace.h      |   29 ++++++++++++++++++++
> >  arch/x86/mm/fault.c                   |    2 +-
> >  arch/x86/vdso/vdso.S                  |    1 +
> >  arch/x86/xen/enlighten.c              |    4 +++
> >  arch/x86/xen/mmu.c                    |    4 ++-
> >  12 files changed, 102 insertions(+), 31 deletions(-)
> >  create mode 100644 arch/x86/kernel/vsyscall_trace.h
> > 
> > -- 
> > 1.7.6

Sander Eikelenboom

2011-Aug-03 17:34 UTC

head link

[Xen-devel] [PATCH v2 0/6] Collected vdso/vsyscall fixes for 3.1

Hello Andy,

Wednesday, August 3, 2011, 3:31:48 PM, you wrote:
> This fixes various problems that cropped up with the vdso patches.
>  - Patch 1 fixes an information leak to userspace.
>  - Patches 2 and 3 fix the kernel build on gold.
>  - Patches 4 and 5 fix Xen (I hope).
>  - Patch 6 (optional) adds a trace event to vsyscall emulation.  It will
>    make it easier to handle performance regression reports :)
> [1] https://gitorious.org/linux-test-utils/linux-clock-tests
> Changes from v1:
>  - Improve changelog message for "x86-64/xen: Enable the vvar
mapping"
>  - Fix 32-bit build.
>  - Add patch 6.
> Andy Lutomirski (6):
>   x86-64: Pad vDSO to a page boundary
>   x86-64: Move the "user" vsyscall segment out of the data
segment.
>   x86-64: Work around gold bug 13023
>   x86-64/xen: Enable the vvar mapping
>   x86-64: Add user_64bit_mode paravirt op
>   x86-64: Add vsyscall:emulate_vsyscall trace event
>  arch/x86/include/asm/desc.h           |    4 +-
>  arch/x86/include/asm/paravirt_types.h |    6 ++++
>  arch/x86/include/asm/ptrace.h         |   19 +++++++++++++
>  arch/x86/kernel/paravirt.c            |    4 +++
>  arch/x86/kernel/step.c                |    2 +-
>  arch/x86/kernel/vmlinux.lds.S         |   46
++++++++++++++++++---------------
>  arch/x86/kernel/vsyscall_64.c         |   12 +++++---
>  arch/x86/kernel/vsyscall_trace.h      |   29 ++++++++++++++++++++
>  arch/x86/mm/fault.c                   |    2 +-
>  arch/x86/vdso/vdso.S                  |    1 +
>  arch/x86/xen/enlighten.c              |    4 +++
>  arch/x86/xen/mmu.c                    |    4 ++-
>  12 files changed, 102 insertions(+), 31 deletions(-)
>  create mode 100644 arch/x86/kernel/vsyscall_trace.h
Compile and boot tested on Xen 4.1.1 and baremetal on x86_64, it fixes my boot
panic under Xen.

Tested-by: Sander Eikelenboom <linux at eikelenboom.it>

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Xen devel - Aug 2011 - [PATCH v2 0/6] Collected vdso/vsyscall fixes for 3.1

[PATCH v2 0/6] Collected vdso/vsyscall fixes for 3.1

[PATCH v2 1/6] x86-64: Pad vDSO to a page boundary

[PATCH v2 2/6] x86-64: Move the "user" vsyscall segment out of the data segment.

[PATCH v2 3/6] x86-64: Work around gold bug 13023

[PATCH v2 4/6] x86-64/xen: Enable the vvar mapping

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[PATCH v2 4/6] x86-64/xen: Enable the vvar mapping

[PATCH v2 0/6] Collected vdso/vsyscall fixes for 3.1

[PATCH v2 0/6] Collected vdso/vsyscall fixes for 3.1

[Xen-devel] [PATCH v2 0/6] Collected vdso/vsyscall fixes for 3.1

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