[amd64] clean PRSTATUS_SIZE/SET_PR_FPVALID up properly

To get rid of hardcoded size/offset in those macros we need to have
a definition of i386 variant of struct elf_prstatus.  However, we can't
do that in asm/compat.h - the types needed for that are not there and
adding an include of asm/user32.h into asm/compat.h would cause a lot
of mess.

That could be conveniently done in elfcore-compat.h, but currently there
is nowhere to put arch-dependent parts of it - no asm/elfcore-compat.h.
So we introduce a new file (asm/elfcore-compat.h, present on architectures
that have CONFIG_ARCH_HAS_ELFCORE_COMPAT set, currently only on x86),
have it pulled by linux/elfcore-compat.h and move the definitions there.

As a side benefit, we don't need to worry about accidental inclusion of
that file into binfmt_elf.c itself, so we don't need the dance with
COMPAT_PRSTATUS_SIZE, etc. - only fs/compat_binfmt_elf.c will see
that header.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/arch/Kconfig b/arch/Kconfig
index 78c6f05b10f915f50a8379058d32f93480f8497c..a17ced73b23c2a1ae1345a839d523c1b4a9be61c 100644 (file)
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -1105,6 +1105,9 @@ config HAVE_ARCH_PFN_VALID
 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
        bool
 
+config ARCH_HAS_ELFCORE_COMPAT
+       bool
+
 source "kernel/gcov/Kconfig"
 
 source "scripts/gcc-plugins/Kconfig"

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 7b6dd10b162ac71f4f7dd3ddbe3f8a9a5658fb16..302a6b453c91c2fb3d2afca2aa895bf5000b8285 100644 (file)
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -31,6 +31,7 @@ config X86_64
        select MODULES_USE_ELF_RELA
        select NEED_DMA_MAP_STATE
        select SWIOTLB
+       select ARCH_HAS_ELFCORE_COMPAT
 
 config FORCE_DYNAMIC_FTRACE
        def_bool y

diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h
index 15cf0f831deeff6db6b5f6da997cf4ed72a7514b..be09c7eac89f092ffa37f71d75791d4e1daa91c0 100644 (file)
--- a/arch/x86/include/asm/compat.h
+++ b/arch/x86/include/asm/compat.h
@@ -159,20 +159,6 @@ struct compat_shmid64_ds {
        compat_ulong_t __unused5;
 };
 
-/*
- * The type of struct elf_prstatus.pr_reg in compatible core dumps.
- */
-typedef struct user_regs_struct compat_elf_gregset_t;
-
-/* Full regset -- prstatus on x32, otherwise on ia32 */
-#define COMPAT_PRSTATUS_SIZE (user_64bit_mode(task_pt_regs(current)) \
-       ? sizeof(struct compat_elf_prstatus) \
-       : 144)
-#define COMPAT_SET_PR_FPVALID(S) \
-       (*(user_64bit_mode(task_pt_regs(current)) \
-              ? &(S)->pr_fpvalid       \
-               : (int *)((void *)(S) + 140)) = 1)
-
 #ifdef CONFIG_X86_X32_ABI
 #define COMPAT_USE_64BIT_TIME \
        (!!(task_pt_regs(current)->orig_ax & __X32_SYSCALL_BIT))

diff --git a/arch/x86/include/asm/elfcore-compat.h b/arch/x86/include/asm/elfcore-compat.h
new file mode 100644 (file)
index 0000000..f1b6c7a
--- /dev/null
+++ b/arch/x86/include/asm/elfcore-compat.h
@@ -0,0 +1,31 @@
+#ifndef _ASM_X86_ELFCORE_COMPAT_H
+#define _ASM_X86_ELFCORE_COMPAT_H
+
+#include <asm/user32.h>
+
+/*
+ * On amd64 we have two 32bit ABIs - i386 and x32.  The latter
+ * has bigger registers, so we use it for compat_elf_regset_t.
+ * The former uses i386_elf_prstatus and PRSTATUS_SIZE/SET_PR_FPVALID
+ * are used to choose the size and location of ->pr_fpvalid of
+ * the layout actually used.
+ */
+typedef struct user_regs_struct compat_elf_gregset_t;
+
+struct i386_elf_prstatus
+{
+       struct compat_elf_prstatus_common       common;
+       struct user_regs_struct32               pr_reg;
+       compat_int_t                    pr_fpvalid;
+};
+
+#define PRSTATUS_SIZE \
+       (user_64bit_mode(task_pt_regs(current)) \
+               ? sizeof(struct compat_elf_prstatus) \
+               : sizeof(struct i386_elf_prstatus))
+#define SET_PR_FPVALID(S) \
+       (*(user_64bit_mode(task_pt_regs(current)) \
+               ? &(S)->pr_fpvalid      \
+               : &((struct i386_elf_prstatus *)(S))->pr_fpvalid) = 1)
+
+#endif

diff --git a/fs/compat_binfmt_elf.c b/fs/compat_binfmt_elf.c
index feb48a5c2d441c394baa07bd26301abc99330f7f..a6321415aba01ff8b11c16e34a8a97b97d651f12 100644 (file)
--- a/fs/compat_binfmt_elf.c
+++ b/fs/compat_binfmt_elf.c
@@ -96,14 +96,6 @@
 #define        ELF_EXEC_PAGESIZE       COMPAT_ELF_EXEC_PAGESIZE
 #endif
 
-#ifdef COMPAT_PRSTATUS_SIZE
-#define        PRSTATUS_SIZE COMPAT_PRSTATUS_SIZE
-#endif
-
-#ifdef COMPAT_SET_PR_FPVALID
-#define        SET_PR_FPVALID(S) COMPAT_SET_PR_FPVALID(S)
-#endif
-
 #ifdef COMPAT_ELF_PLAT_INIT
 #undef ELF_PLAT_INIT
 #define        ELF_PLAT_INIT           COMPAT_ELF_PLAT_INIT

diff --git a/include/linux/elfcore-compat.h b/include/linux/elfcore-compat.h
index 4aeda5f1f038580a6e803176b90aff65ac55520d..e272c3d452ce786aabca7b96172bfc91c0c47a6a 100644 (file)
--- a/include/linux/elfcore-compat.h
+++ b/include/linux/elfcore-compat.h
@@ -33,13 +33,6 @@ struct compat_elf_prstatus_common
        struct old_timeval32            pr_cstime;
 };
 
-struct compat_elf_prstatus
-{
-       struct compat_elf_prstatus_common       common;
-       compat_elf_gregset_t            pr_reg;
-       compat_int_t                    pr_fpvalid;
-};
-
 struct compat_elf_prpsinfo
 {
        char                            pr_state;
@@ -54,4 +47,15 @@ struct compat_elf_prpsinfo
        char                            pr_psargs[ELF_PRARGSZ];
 };
 
+#ifdef CONFIG_ARCH_HAS_ELFCORE_COMPAT
+#include <asm/elfcore-compat.h>
+#endif
+
+struct compat_elf_prstatus
+{
+       struct compat_elf_prstatus_common       common;
+       compat_elf_gregset_t            pr_reg;
+       compat_int_t                    pr_fpvalid;
+};
+
 #endif /* _LINUX_ELFCORE_COMPAT_H */