kernel: Fixups on segment loading in Elf handling

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>

kernel/binfmt-elf-for-cr-4 → kernel/binfmt-elf-for-cr-5

@@ -9,13 +9,18 @@ Elf file format, which includes
    PT_CKPT_CORE -- 'core_entry' structure and PT_CKPT_PAGES --
    a set of all pages which are to be read into process memory.
 
+v2: (from Andrew Vagin)
+ - load fs_base and gs_base via do_arch_prctl
+ - don't load tls and segments, it will be done in __switch_to
+
 Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
+Signed-off-by: Andrew Vagin <avagin@openvz.org>
 ---
  arch/x86/include/asm/elf.h |    3 
  arch/x86/vdso/vma.c        |   22 ++
- fs/binfmt_elf.c            |  405 ++++++++++++++++++++++++++++++++++++++++++++-
+ fs/binfmt_elf.c            |  402 ++++++++++++++++++++++++++++++++++++++++++++-
  include/linux/elf_ckpt.h   |  135 +++++++++++++++
- 4 files changed, 563 insertions(+), 2 deletions(-)
+ 4 files changed, 560 insertions(+), 2 deletions(-)
 
 Index: linux-2.6.git/arch/x86/include/asm/elf.h
 ===================================================================
@@ -68,19 +73,22 @@ Index: linux-2.6.git/fs/binfmt_elf.c
 ===================================================================
 --- linux-2.6.git.orig/fs/binfmt_elf.c
 +++ linux-2.6.git/fs/binfmt_elf.c
-@@ -36,6 +36,11 @@
+@@ -35,6 +35,14 @@
+ #include <asm/uaccess.h>
  #include <asm/param.h>
  #include <asm/page.h>
- 
++#include <asm/prctl.h>
++#include <asm/proto.h>
++
++
 +#include <linux/elf_ckpt.h>
 +#include <linux/flex_array.h>
 +#include <asm/tlbflush.h>
 +#include <asm/desc.h>
-+
+ 
  static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs);
  static int load_elf_library(struct file *);
- static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *,
-@@ -556,6 +561,396 @@ static unsigned long randomize_stack_top
+@@ -556,6 +564,390 @@ static unsigned long randomize_stack_top
  #endif
  }
  
@@ -109,7 +117,7 @@ Index: linux-2.6.git/fs/binfmt_elf.c
 +	int i, ret = -ENOEXEC;
 +	loff_t off;
 +
-+	int cpu, seg;
++	int cpu;
 +
 +	BUILD_BUG_ON(CKPT_GDT_ENTRY_TLS_ENTRIES != GDT_ENTRY_TLS_ENTRIES);
 +	BUILD_BUG_ON(CKPT_PAGE_SIZE != PAGE_SIZE);
@@ -430,23 +438,17 @@ Index: linux-2.6.git/fs/binfmt_elf.c
 +		thread->tls_array[i].b = core_entry.tls_array[i].b;
 +	}
 +
-+	load_TLS(thread, cpu);
-+
-+	seg = thread->fsindex;
-+	loadsegment(fs, seg);
-+	savesegment(fs, seg);
-+
-+	if (seg != thread->fsindex) {
-+		pr_err("Fixup on FS loading exception: %i %i\n",
-+			thread->fsindex, seg);
++	if (core_entry.gpregs.fs_base) {
++		ret = do_arch_prctl(current, ARCH_SET_FS, core_entry.gpregs.fs_base);
++		if (ret)
++			goto out_unmap;
 +	}
 +
-+	if (core_entry.gpregs.fs_base)
-+		wrmsrl(MSR_FS_BASE, core_entry.gpregs.fs_base);
-+
-+	load_gs_index(thread->gsindex);
-+	if (core_entry.gpregs.gs_base)
-+		wrmsrl(MSR_GS_BASE, core_entry.gpregs.gs_base);
++	if (core_entry.gpregs.gs_base) {
++		ret = do_arch_prctl(current, ARCH_SET_GS, core_entry.gpregs.gs_base);
++		if (ret)
++			goto out_unmap;
++	}
 +
 +	put_cpu();
 +
@@ -477,7 +479,7 @@ Index: linux-2.6.git/fs/binfmt_elf.c
  static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
  {
  	struct file *interpreter = NULL; /* to shut gcc up */
-@@ -592,7 +987,9 @@ static int load_elf_binary(struct linux_
+@@ -592,7 +984,9 @@ static int load_elf_binary(struct linux_
  	if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
  		goto out;
  
@@ -488,7 +490,7 @@ Index: linux-2.6.git/fs/binfmt_elf.c
  		goto out;
  	if (!elf_check_arch(&loc->elf_ex))
  		goto out;
-@@ -619,6 +1016,12 @@ static int load_elf_binary(struct linux_
+@@ -619,6 +1013,12 @@ static int load_elf_binary(struct linux_
  		goto out_free_ph;
  	}