From 8a00dd0012f383fc0c39b169b694dc15236cec7c Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Mon, 22 Jun 2020 20:14:02 -0400
Subject: [PATCH 01/13] binfmt_elf: partially sanitize PRSTATUS_SIZE and
 SET_PR_FPVALID

On 64bit architectures that support 32bit processes there are
two possible layouts for NT_PRSTATUS note in ELF coredumps.
For one thing, several fields are 64bit for native processes
and 32bit for compat ones (pr_sigpend, etc.).  For another,
the register dump is obviously different - the size and number
of registers are not going to be the same for 32bit and 64bit
variants of processor.

Usually that's handled by having two structures - elf_prstatus
for native layout and compat_elf_prstatus for 32bit one.
32bit processes are handled by fs/compat_binfmt_elf.c, which
defines a macro called 'elf_prstatus' that expands to compat_elf_prstatus.
Then it includes fs/binfmt_elf.c, which makes all references to
struct elf_prstatus to be textually replaced with struct
compat_elf_prstatus.  Ugly and somewhat brittle, but it works.

However, amd64 is worse - there are _three_ possible layouts.
One for native 64bit processes, another for i386 (32bit) processes
and yet another for x32 (32bit address space with full 64bit
registers).

Both i386 and x32 processes are handled by fs/compat_binfmt_elf.c,
with usual compat_binfmt_elf.c trickery.  However, the layouts
for i386 and x32 are not identical - they have the common beginning,
but the register dump part (pr_reg) is bigger on x32.  Worse, pr_reg
is not the last field - it's followed by int pr_fpvalid, so that
field ends up at different offsets for i386 and x32 layouts.

Fortunately, there's not much code that cares about any of that -
it's all encapsulated in fill_thread_core_info().  Since x32
variant is bigger, we define compat_elf_prstatus to match that
layout.  That way i386 processes have enough space to fit
their layout into.

Moreover, since these layouts are identical prior to pr_reg,
we don't need to distinguish x32 and i386 cases when we are
setting the fields prior to pr_reg.

Filling pr_reg itself is done by calling ->get() method of
appropriate regset, and that method knows what layout (and size)
to use.

We do need to distinguish x32 and i386 cases only for two
things: setting ->pr_fpvalid (offset differs for x32 and
i386) and choosing the right size for our note.

The way it's done is Not Nice, for the lack of more accurate
printable description.  There are two macros (PRSTATUS_SIZE and
SET_PR_FPVALID), that default essentially to sizeof(struct elf_prstatus)
and (S)->pr_fpvalid = 1.  On x86 asm/compat.h provides its own
variants.

Unfortunately, quite a few things go wrong there:
	* PRSTATUS_SIZE doesn't use the normal test for process
being an x32 one; it compares the size reported by regset with
the size of pr_reg.
	* it hardcodes the sizes of x32 and i386 variants (296 and 144
resp.), so if some change in includes leads to asm/compat.h pulled
in by fs/binfmt_elf.c we are in trouble - it will end up using
the size of x32 variant for 64bit processes.
	* it's in the wrong place; asm/compat.h couldn't define
the structure for i386 layout, since it lacks quite a few types
needed for it.  Hardcoded sizes are largely due to that.

The proper fix would be to have an explicitly defined i386 variant
of structure and have PRSTATUS_SIZE/SET_PR_FPVALID check for
TIF_X32 to choose the variant that should be used.  Unfortunately,
that requires some manipulations of headers; we'll do that later
in the series, but for now let's go with the minimal variant -
rename PRSTATUS_SIZE in asm/compat.h to COMPAT_PRSTATUS_SIZE,
have fs/compat_binfmt_elf.c define PRSTATUS_SIZE to COMPAT_PRSTATUS_SIZE
and use the normal TIF_X32 check in that macro.  The size of i386 variant
is kept hardcoded for now.  Similar story for SET_PR_FPVALID.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 arch/x86/include/asm/compat.h | 11 +++++++----
 fs/binfmt_elf.c               | 13 +++++--------
 fs/compat_binfmt_elf.c        |  8 ++++++++
 3 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h
index f145e3326c6d..15cf0f831dee 100644
--- a/arch/x86/include/asm/compat.h
+++ b/arch/x86/include/asm/compat.h
@@ -165,10 +165,13 @@ struct compat_shmid64_ds {
 typedef struct user_regs_struct compat_elf_gregset_t;
 
 /* Full regset -- prstatus on x32, otherwise on ia32 */
-#define PRSTATUS_SIZE(S, R) (R != sizeof(S.pr_reg) ? 144 : 296)
-#define SET_PR_FPVALID(S, V, R) \
-  do { *(int *) (((void *) &((S)->pr_reg)) + R) = (V); } \
-  while (0)
+#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 \
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 950bc177238a..8380478d3d92 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1717,11 +1717,11 @@ static void do_thread_regset_writeback(struct task_struct *task,
 }
 
 #ifndef PRSTATUS_SIZE
-#define PRSTATUS_SIZE(S, R) sizeof(S)
+#define PRSTATUS_SIZE sizeof(struct elf_prstatus)
 #endif
 
 #ifndef SET_PR_FPVALID
-#define SET_PR_FPVALID(S, V, R) ((S)->pr_fpvalid = (V))
+#define SET_PR_FPVALID(S) ((S)->pr_fpvalid = 1)
 #endif
 
 static int fill_thread_core_info(struct elf_thread_core_info *t,
@@ -1729,7 +1729,6 @@ static int fill_thread_core_info(struct elf_thread_core_info *t,
 				 long signr, size_t *total)
 {
 	unsigned int i;
-	int regset0_size;
 
 	/*
 	 * NT_PRSTATUS is the one special case, because the regset data
@@ -1738,13 +1737,11 @@ static int fill_thread_core_info(struct elf_thread_core_info *t,
 	 * We assume that regset 0 is NT_PRSTATUS.
 	 */
 	fill_prstatus(&t->prstatus, t->task, signr);
-	regset0_size = regset_get(t->task, &view->regsets[0],
+	regset_get(t->task, &view->regsets[0],
 		   sizeof(t->prstatus.pr_reg), &t->prstatus.pr_reg);
-	if (regset0_size < 0)
-		return 0;
 
 	fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
-		  PRSTATUS_SIZE(t->prstatus, regset0_size), &t->prstatus);
+		  PRSTATUS_SIZE, &t->prstatus);
 	*total += notesize(&t->notes[0]);
 
 	do_thread_regset_writeback(t->task, &view->regsets[0]);
@@ -1772,7 +1769,7 @@ static int fill_thread_core_info(struct elf_thread_core_info *t,
 			continue;
 
 		if (is_fpreg)
-			SET_PR_FPVALID(&t->prstatus, 1, regset0_size);
+			SET_PR_FPVALID(&t->prstatus);
 
 		fill_note(&t->notes[i], is_fpreg ? "CORE" : "LINUX",
 			  note_type, ret, data);
diff --git a/fs/compat_binfmt_elf.c b/fs/compat_binfmt_elf.c
index 2c557229696a..962df845ed51 100644
--- a/fs/compat_binfmt_elf.c
+++ b/fs/compat_binfmt_elf.c
@@ -95,6 +95,14 @@
 #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

From f2485a2dc9f0f30fbdd013ad5772975100c71360 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Sat, 13 Jun 2020 00:08:44 -0400
Subject: [PATCH 02/13] elf_prstatus: collect the common part (everything
 before pr_reg) into a struct

Preparations to doing i386 compat elf_prstatus sanely - rather than duplicating
the beginning of compat_elf_prstatus, take these fields into a separate
structure (compat_elf_prstatus_common), so that it could be reused.  Due to
the incestous relationship between binfmt_elf.c and compat_binfmt_elf.c we
need the same shape change done to native struct elf_prstatus, gathering the
fields prior to pr_reg into a new structure (struct elf_prstatus_common).

Fortunately, offset of pr_reg is always a multiple of 16 with no padding
right before it, so it's possible to turn all the stuff prior to it into
a single member without disturbing the layout.

[build fix from Geert Uytterhoeven folded in]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 arch/ia64/kernel/crash.c                   |  2 +-
 arch/mips/kernel/binfmt_elfn32.c           |  7 ++++++-
 arch/mips/kernel/binfmt_elfo32.c           |  6 +++++-
 arch/powerpc/platforms/powernv/opal-core.c |  6 +++---
 arch/s390/kernel/crash_dump.c              |  2 +-
 fs/binfmt_elf.c                            |  8 ++++----
 fs/binfmt_elf_fdpic.c                      | 22 +++++-----------------
 fs/compat_binfmt_elf.c                     |  1 +
 include/linux/elfcore-compat.h             |  7 ++++++-
 include/linux/elfcore.h                    |  7 ++++++-
 kernel/kexec_core.c                        |  2 +-
 11 files changed, 39 insertions(+), 31 deletions(-)

diff --git a/arch/ia64/kernel/crash.c b/arch/ia64/kernel/crash.c
index fec70d662d0c..4f47741005d2 100644
--- a/arch/ia64/kernel/crash.c
+++ b/arch/ia64/kernel/crash.c
@@ -43,7 +43,7 @@ crash_save_this_cpu(void)
 
 	elf_greg_t *dst = (elf_greg_t *)&(prstatus->pr_reg);
 	memset(prstatus, 0, sizeof(*prstatus));
-	prstatus->pr_pid = current->pid;
+	prstatus->common.pr_pid = current->pid;
 
 	ia64_dump_cpu_regs(dst);
 	cfm = dst[43];
diff --git a/arch/mips/kernel/binfmt_elfn32.c b/arch/mips/kernel/binfmt_elfn32.c
index 6ee3f7218c67..136dc0c9300d 100644
--- a/arch/mips/kernel/binfmt_elfn32.c
+++ b/arch/mips/kernel/binfmt_elfn32.c
@@ -44,7 +44,8 @@ typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
 #include <linux/math64.h>
 
 #define elf_prstatus elf_prstatus32
-struct elf_prstatus32
+#define elf_prstatus_common elf_prstatus32_common
+struct elf_prstatus32_common
 {
 	struct elf_siginfo pr_info;	/* Info associated with signal */
 	short	pr_cursig;		/* Current signal */
@@ -58,6 +59,10 @@ struct elf_prstatus32
 	struct old_timeval32 pr_stime; /* System time */
 	struct old_timeval32 pr_cutime;/* Cumulative user time */
 	struct old_timeval32 pr_cstime;/* Cumulative system time */
+};
+struct elf_prstatus32
+{
+	struct elf_prstatus32_common common:
 	elf_gregset_t pr_reg;	/* GP registers */
 	int pr_fpvalid;		/* True if math co-processor being used.  */
 };
diff --git a/arch/mips/kernel/binfmt_elfo32.c b/arch/mips/kernel/binfmt_elfo32.c
index 6dd103d3cebb..b1f4b8f1dee7 100644
--- a/arch/mips/kernel/binfmt_elfo32.c
+++ b/arch/mips/kernel/binfmt_elfo32.c
@@ -49,7 +49,7 @@ typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
 #include <linux/math64.h>
 
 #define elf_prstatus elf_prstatus32
-struct elf_prstatus32
+struct elf_prstatus32_common
 {
 	struct elf_siginfo pr_info;	/* Info associated with signal */
 	short	pr_cursig;		/* Current signal */
@@ -63,6 +63,10 @@ struct elf_prstatus32
 	struct old_timeval32 pr_stime; /* System time */
 	struct old_timeval32 pr_cutime;/* Cumulative user time */
 	struct old_timeval32 pr_cstime;/* Cumulative system time */
+};
+struct elf_prstatus32
+{
+	struct elf_prstatus32_common common:
 	elf_gregset_t pr_reg;	/* GP registers */
 	int pr_fpvalid;		/* True if math co-processor being used.  */
 };
diff --git a/arch/powerpc/platforms/powernv/opal-core.c b/arch/powerpc/platforms/powernv/opal-core.c
index 23571f0b555a..0d9ba70f7251 100644
--- a/arch/powerpc/platforms/powernv/opal-core.c
+++ b/arch/powerpc/platforms/powernv/opal-core.c
@@ -119,8 +119,8 @@ static void fill_prstatus(struct elf_prstatus *prstatus, int pir,
 	 * As a PIR value could also be '0', add an offset of '100'
 	 * to every PIR to avoid misinterpretations in GDB.
 	 */
-	prstatus->pr_pid  = cpu_to_be32(100 + pir);
-	prstatus->pr_ppid = cpu_to_be32(1);
+	prstatus->common.pr_pid  = cpu_to_be32(100 + pir);
+	prstatus->common.pr_ppid = cpu_to_be32(1);
 
 	/*
 	 * Indicate SIGUSR1 for crash initiated from kernel.
@@ -130,7 +130,7 @@ static void fill_prstatus(struct elf_prstatus *prstatus, int pir,
 		short sig;
 
 		sig = kernel_initiated ? SIGUSR1 : SIGTERM;
-		prstatus->pr_cursig = cpu_to_be16(sig);
+		prstatus->common.pr_cursig = cpu_to_be16(sig);
 	}
 }
 
diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c
index 205b2e2648aa..0e36dfc9ccd6 100644
--- a/arch/s390/kernel/crash_dump.c
+++ b/arch/s390/kernel/crash_dump.c
@@ -365,7 +365,7 @@ static void *fill_cpu_elf_notes(void *ptr, int cpu, struct save_area *sa)
 	memcpy(&nt_prstatus.pr_reg.gprs, sa->gprs, sizeof(sa->gprs));
 	memcpy(&nt_prstatus.pr_reg.psw, sa->psw, sizeof(sa->psw));
 	memcpy(&nt_prstatus.pr_reg.acrs, sa->acrs, sizeof(sa->acrs));
-	nt_prstatus.pr_pid = cpu;
+	nt_prstatus.common.pr_pid = cpu;
 	/* Prepare fpregset (floating point) note */
 	memset(&nt_fpregset, 0, sizeof(nt_fpregset));
 	memcpy(&nt_fpregset.fpc, &sa->fpc, sizeof(sa->fpc));
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 8380478d3d92..4c1550b13899 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1495,7 +1495,7 @@ static void fill_note(struct memelfnote *note, const char *name, int type,
  * fill up all the fields in prstatus from the given task struct, except
  * registers which need to be filled up separately.
  */
-static void fill_prstatus(struct elf_prstatus *prstatus,
+static void fill_prstatus(struct elf_prstatus_common *prstatus,
 		struct task_struct *p, long signr)
 {
 	prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
@@ -1736,7 +1736,7 @@ static int fill_thread_core_info(struct elf_thread_core_info *t,
 	 * than being the whole note contents.  We fill the reset in here.
 	 * We assume that regset 0 is NT_PRSTATUS.
 	 */
-	fill_prstatus(&t->prstatus, t->task, signr);
+	fill_prstatus(&t->prstatus.common, t->task, signr);
 	regset_get(t->task, &view->regsets[0],
 		   sizeof(t->prstatus.pr_reg), &t->prstatus.pr_reg);
 
@@ -1958,7 +1958,7 @@ static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
 	struct task_struct *p = t->thread;
 	t->num_notes = 0;
 
-	fill_prstatus(&t->prstatus, p, signr);
+	fill_prstatus(&t->prstatus.common, p, signr);
 	elf_core_copy_task_regs(p, &t->prstatus.pr_reg);	
 	
 	fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
@@ -2037,7 +2037,7 @@ static int fill_note_info(struct elfhdr *elf, int phdrs,
 	}
 	/* now collect the dump for the current */
 	memset(info->prstatus, 0, sizeof(*info->prstatus));
-	fill_prstatus(info->prstatus, current, siginfo->si_signo);
+	fill_prstatus(&info->prstatus->common, current, siginfo->si_signo);
 	elf_core_copy_regs(&info->prstatus->pr_reg, regs);
 
 	/* Set up header */
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index be4062b8ba75..03d81a14bcbf 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -1191,18 +1191,7 @@ static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
 
 struct elf_prstatus_fdpic
 {
-	struct elf_siginfo pr_info;	/* Info associated with signal */
-	short	pr_cursig;		/* Current signal */
-	unsigned long pr_sigpend;	/* Set of pending signals */
-	unsigned long pr_sighold;	/* Set of held signals */
-	pid_t	pr_pid;
-	pid_t	pr_ppid;
-	pid_t	pr_pgrp;
-	pid_t	pr_sid;
-	struct __kernel_old_timeval pr_utime;	/* User time */
-	struct __kernel_old_timeval pr_stime;	/* System time */
-	struct __kernel_old_timeval pr_cutime;	/* Cumulative user time */
-	struct __kernel_old_timeval pr_cstime;	/* Cumulative system time */
+	struct elf_prstatus_common	common;
 	elf_gregset_t pr_reg;	/* GP registers */
 	/* When using FDPIC, the loadmap addresses need to be communicated
 	 * to GDB in order for GDB to do the necessary relocations.  The
@@ -1301,7 +1290,7 @@ static inline void fill_note(struct memelfnote *note, const char *name, int type
  * fill up all the fields in prstatus from the given task struct, except
  * registers which need to be filled up separately.
  */
-static void fill_prstatus(struct elf_prstatus_fdpic *prstatus,
+static void fill_prstatus(struct elf_prstatus_common *prstatus,
 			  struct task_struct *p, long signr)
 {
 	prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
@@ -1332,9 +1321,6 @@ static void fill_prstatus(struct elf_prstatus_fdpic *prstatus,
 	}
 	prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime);
 	prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime);
-
-	prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
-	prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
 }
 
 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
@@ -1405,7 +1391,9 @@ static struct elf_thread_status *elf_dump_thread_status(long signr, struct task_
 	if (!t)
 		return t;
 
-	fill_prstatus(&t->prstatus, p, signr);
+	fill_prstatus(&t->prstatus.common, p, signr);
+	t->prstatus.pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
+	t->prstatus.pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
 	regset_get(p, &view->regsets[0],
 		   sizeof(t->prstatus.pr_reg), &t->prstatus.pr_reg);
 
diff --git a/fs/compat_binfmt_elf.c b/fs/compat_binfmt_elf.c
index 962df845ed51..feb48a5c2d44 100644
--- a/fs/compat_binfmt_elf.c
+++ b/fs/compat_binfmt_elf.c
@@ -50,6 +50,7 @@
  * which requires asm/elf.h to define compat_elf_gregset_t et al.
  */
 #define elf_prstatus	compat_elf_prstatus
+#define elf_prstatus_common	compat_elf_prstatus_common
 #define elf_prpsinfo	compat_elf_prpsinfo
 
 #undef ns_to_kernel_old_timeval
diff --git a/include/linux/elfcore-compat.h b/include/linux/elfcore-compat.h
index 10485f0c9740..4aeda5f1f038 100644
--- a/include/linux/elfcore-compat.h
+++ b/include/linux/elfcore-compat.h
@@ -17,7 +17,7 @@ struct compat_elf_siginfo
 	compat_int_t			si_errno;
 };
 
-struct compat_elf_prstatus
+struct compat_elf_prstatus_common
 {
 	struct compat_elf_siginfo	pr_info;
 	short				pr_cursig;
@@ -31,6 +31,11 @@ struct compat_elf_prstatus
 	struct old_timeval32		pr_stime;
 	struct old_timeval32		pr_cutime;
 	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;
 };
diff --git a/include/linux/elfcore.h b/include/linux/elfcore.h
index de51c1bef27d..2aaa15779d50 100644
--- a/include/linux/elfcore.h
+++ b/include/linux/elfcore.h
@@ -29,7 +29,7 @@ struct elf_siginfo
  * the SVR4 structure, but more Linuxy, with things that Linux does
  * not support and which gdb doesn't really use excluded.
  */
-struct elf_prstatus
+struct elf_prstatus_common
 {
 	struct elf_siginfo pr_info;	/* Info associated with signal */
 	short	pr_cursig;		/* Current signal */
@@ -43,6 +43,11 @@ struct elf_prstatus
 	struct __kernel_old_timeval pr_stime;	/* System time */
 	struct __kernel_old_timeval pr_cutime;	/* Cumulative user time */
 	struct __kernel_old_timeval pr_cstime;	/* Cumulative system time */
+};
+
+struct elf_prstatus
+{
+	struct elf_prstatus_common common;
 	elf_gregset_t pr_reg;	/* GP registers */
 	int pr_fpvalid;		/* True if math co-processor being used.  */
 };
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index 4f8efc278aa7..80905e5aa8ae 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -1076,7 +1076,7 @@ void crash_save_cpu(struct pt_regs *regs, int cpu)
 	if (!buf)
 		return;
 	memset(&prstatus, 0, sizeof(prstatus));
-	prstatus.pr_pid = current->pid;
+	prstatus.common.pr_pid = current->pid;
 	elf_core_copy_kernel_regs(&prstatus.pr_reg, regs);
 	buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS,
 			      &prstatus, sizeof(prstatus));

From 7facdc426f86c67e579e49e100943cbccc43e1c6 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Sat, 13 Jun 2020 23:03:25 -0400
Subject: [PATCH 03/13] [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>
---
 arch/Kconfig                          |  3 +++
 arch/x86/Kconfig                      |  1 +
 arch/x86/include/asm/compat.h         | 14 ------------
 arch/x86/include/asm/elfcore-compat.h | 31 +++++++++++++++++++++++++++
 fs/compat_binfmt_elf.c                |  8 -------
 include/linux/elfcore-compat.h        | 18 ++++++++++------
 6 files changed, 46 insertions(+), 29 deletions(-)
 create mode 100644 arch/x86/include/asm/elfcore-compat.h

diff --git a/arch/Kconfig b/arch/Kconfig
index 78c6f05b10f9..a17ced73b23c 100644
--- 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 7b6dd10b162a..302a6b453c91 100644
--- 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 15cf0f831dee..be09c7eac89f 100644
--- 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
index 000000000000..f1b6c7a8d8fc
--- /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 feb48a5c2d44..a6321415aba0 100644
--- 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 4aeda5f1f038..e272c3d452ce 100644
--- 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 */

From 85f2ada718a81b282ee78a96d0ab1450543612e7 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Mon, 4 Jan 2021 18:34:30 -0500
Subject: [PATCH 04/13] x32: make X32, !IA32_EMULATION setups able to execute
 x32 binaries

It's really trivial - the only wrinkle is making sure that
compiler knows that ia32-related side of COMPAT_ARCH_DLINFO
is dead code on such configs (we don't get there without
having passed compat_elf_check_arch(), and on such configs
that'll fail for ia32 binary).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 arch/x86/Kconfig           | 2 +-
 arch/x86/include/asm/elf.h | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 302a6b453c91..a2182d22b5fa 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2864,7 +2864,6 @@ config IA32_EMULATION
 	depends on X86_64
 	select ARCH_WANT_OLD_COMPAT_IPC
 	select BINFMT_ELF
-	select COMPAT_BINFMT_ELF
 	select COMPAT_OLD_SIGACTION
 	help
 	  Include code to run legacy 32-bit programs under a
@@ -2900,6 +2899,7 @@ config COMPAT_32
 config COMPAT
 	def_bool y
 	depends on IA32_EMULATION || X86_X32
+	select COMPAT_BINFMT_ELF if BINFMT_ELF
 
 if COMPAT
 config COMPAT_FOR_U64_ALIGNMENT
diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
index 66bdfe838d61..9224d40cdefe 100644
--- a/arch/x86/include/asm/elf.h
+++ b/arch/x86/include/asm/elf.h
@@ -364,7 +364,7 @@ do {									\
 #define COMPAT_ARCH_DLINFO						\
 if (exec->e_machine == EM_X86_64)					\
 	ARCH_DLINFO_X32;						\
-else									\
+else if (IS_ENABLED(CONFIG_IA32_EMULATION))				\
 	ARCH_DLINFO_IA32
 
 #define COMPAT_ELF_ET_DYN_BASE	(TASK_UNMAPPED_BASE + 0x1000000)

From 6835501e789a94760f34efffff0e4706e3ee1d71 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Sun, 14 Jun 2020 19:22:46 -0400
Subject: [PATCH 05/13] mips binfmt_elf*32.c: use elfcore-compat.h

... rather than duplicating declarations from it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 arch/mips/kernel/binfmt_elfn32.c | 37 ++++----------------------------
 arch/mips/kernel/binfmt_elfo32.c | 36 ++++---------------------------
 2 files changed, 8 insertions(+), 65 deletions(-)

diff --git a/arch/mips/kernel/binfmt_elfn32.c b/arch/mips/kernel/binfmt_elfn32.c
index a11c291b9241..720bbf272744 100644
--- a/arch/mips/kernel/binfmt_elfn32.c
+++ b/arch/mips/kernel/binfmt_elfn32.c
@@ -42,46 +42,17 @@ typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
 #include <linux/elfcore.h>
 #include <linux/compat.h>
 #include <linux/math64.h>
+#include <linux/elfcore-compat.h>
 
 #define elf_prstatus elf_prstatus32
-#define elf_prstatus_common elf_prstatus32_common
-struct elf_prstatus32_common
-{
-	struct elf_siginfo pr_info;	/* Info associated with signal */
-	short	pr_cursig;		/* Current signal */
-	unsigned int pr_sigpend;	/* Set of pending signals */
-	unsigned int pr_sighold;	/* Set of held signals */
-	pid_t	pr_pid;
-	pid_t	pr_ppid;
-	pid_t	pr_pgrp;
-	pid_t	pr_sid;
-	struct old_timeval32 pr_utime; /* User time */
-	struct old_timeval32 pr_stime; /* System time */
-	struct old_timeval32 pr_cutime;/* Cumulative user time */
-	struct old_timeval32 pr_cstime;/* Cumulative system time */
-};
+#define elf_prstatus_common compat_elf_prstatus_common
 struct elf_prstatus32
 {
-	struct elf_prstatus32_common common:
+	struct compat_elf_prstatus_common common;
 	elf_gregset_t pr_reg;	/* GP registers */
 	int pr_fpvalid;		/* True if math co-processor being used.  */
 };
-
-#define elf_prpsinfo elf_prpsinfo32
-struct elf_prpsinfo32
-{
-	char	pr_state;	/* numeric process state */
-	char	pr_sname;	/* char for pr_state */
-	char	pr_zomb;	/* zombie */
-	char	pr_nice;	/* nice val */
-	unsigned int pr_flag;	/* flags */
-	__kernel_uid_t	pr_uid;
-	__kernel_gid_t	pr_gid;
-	pid_t	pr_pid, pr_ppid, pr_pgrp, pr_sid;
-	/* Lots missing */
-	char	pr_fname[16];	/* filename of executable */
-	char	pr_psargs[ELF_PRARGSZ]; /* initial part of arg list */
-};
+#define elf_prpsinfo compat_elf_prpsinfo
 
 #define elf_caddr_t	u32
 #define init_elf_binfmt init_elfn32_binfmt
diff --git a/arch/mips/kernel/binfmt_elfo32.c b/arch/mips/kernel/binfmt_elfo32.c
index afe8940d4952..6fcab231c962 100644
--- a/arch/mips/kernel/binfmt_elfo32.c
+++ b/arch/mips/kernel/binfmt_elfo32.c
@@ -47,45 +47,17 @@ typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
 #include <linux/elfcore.h>
 #include <linux/compat.h>
 #include <linux/math64.h>
+#include <linux/elfcore-compat.h>
 
 #define elf_prstatus elf_prstatus32
-struct elf_prstatus32_common
-{
-	struct elf_siginfo pr_info;	/* Info associated with signal */
-	short	pr_cursig;		/* Current signal */
-	unsigned int pr_sigpend;	/* Set of pending signals */
-	unsigned int pr_sighold;	/* Set of held signals */
-	pid_t	pr_pid;
-	pid_t	pr_ppid;
-	pid_t	pr_pgrp;
-	pid_t	pr_sid;
-	struct old_timeval32 pr_utime; /* User time */
-	struct old_timeval32 pr_stime; /* System time */
-	struct old_timeval32 pr_cutime;/* Cumulative user time */
-	struct old_timeval32 pr_cstime;/* Cumulative system time */
-};
+#define elf_prstatus_common compat_elf_prstatus_common
 struct elf_prstatus32
 {
-	struct elf_prstatus32_common common:
+	struct compat_elf_prstatus_common common;
 	elf_gregset_t pr_reg;	/* GP registers */
 	int pr_fpvalid;		/* True if math co-processor being used.  */
 };
-
-#define elf_prpsinfo elf_prpsinfo32
-struct elf_prpsinfo32
-{
-	char	pr_state;	/* numeric process state */
-	char	pr_sname;	/* char for pr_state */
-	char	pr_zomb;	/* zombie */
-	char	pr_nice;	/* nice val */
-	unsigned int pr_flag;	/* flags */
-	__kernel_uid_t	pr_uid;
-	__kernel_gid_t	pr_gid;
-	pid_t	pr_pid, pr_ppid, pr_pgrp, pr_sid;
-	/* Lots missing */
-	char	pr_fname[16];	/* filename of executable */
-	char	pr_psargs[ELF_PRARGSZ]; /* initial part of arg list */
-};
+#define elf_prpsinfo compat_elf_prpsinfo
 
 #define elf_caddr_t	u32
 #define init_elf_binfmt init_elf32_binfmt

From c3cd7564819a7c1761b3b91770b6083cb29b2620 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Wed, 10 Jun 2020 18:09:06 -0400
Subject: [PATCH 06/13] mips: kill unused definitions in binfmt_elf[on]32.c

elf_caddr_t: unused since 2002
jiffies_to_timeval: unused since 2015
TASK_SIZE: used only downstream of SET_PERSONALITY2(), and after that
point the normal definition results in TASK_SIZE32 just fine.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 arch/mips/kernel/binfmt_elfn32.c | 18 ------------------
 arch/mips/kernel/binfmt_elfo32.c | 18 ------------------
 2 files changed, 36 deletions(-)

diff --git a/arch/mips/kernel/binfmt_elfn32.c b/arch/mips/kernel/binfmt_elfn32.c
index 720bbf272744..4c5544ae8fa4 100644
--- a/arch/mips/kernel/binfmt_elfn32.c
+++ b/arch/mips/kernel/binfmt_elfn32.c
@@ -54,28 +54,10 @@ struct elf_prstatus32
 };
 #define elf_prpsinfo compat_elf_prpsinfo
 
-#define elf_caddr_t	u32
 #define init_elf_binfmt init_elfn32_binfmt
 
-#define jiffies_to_timeval jiffies_to_old_timeval32
-static __inline__ void
-jiffies_to_old_timeval32(unsigned long jiffies, struct old_timeval32 *value)
-{
-	/*
-	 * Convert jiffies to nanoseconds and separate with
-	 * one divide.
-	 */
-	u64 nsec = (u64)jiffies * TICK_NSEC;
-	u32 rem;
-	value->tv_sec = div_u64_rem(nsec, NSEC_PER_SEC, &rem);
-	value->tv_usec = rem / NSEC_PER_USEC;
-}
-
 #define ELF_CORE_EFLAGS EF_MIPS_ABI2
 
-#undef TASK_SIZE
-#define TASK_SIZE TASK_SIZE32
-
 #undef ns_to_kernel_old_timeval
 #define ns_to_kernel_old_timeval ns_to_old_timeval32
 
diff --git a/arch/mips/kernel/binfmt_elfo32.c b/arch/mips/kernel/binfmt_elfo32.c
index 6fcab231c962..6ba7501e7079 100644
--- a/arch/mips/kernel/binfmt_elfo32.c
+++ b/arch/mips/kernel/binfmt_elfo32.c
@@ -59,26 +59,8 @@ struct elf_prstatus32
 };
 #define elf_prpsinfo compat_elf_prpsinfo
 
-#define elf_caddr_t	u32
 #define init_elf_binfmt init_elf32_binfmt
 
-#define jiffies_to_timeval jiffies_to_old_timeval32
-static inline void
-jiffies_to_old_timeval32(unsigned long jiffies, struct old_timeval32 *value)
-{
-	/*
-	 * Convert jiffies to nanoseconds and separate with
-	 * one divide.
-	 */
-	u64 nsec = (u64)jiffies * TICK_NSEC;
-	u32 rem;
-	value->tv_sec = div_u64_rem(nsec, NSEC_PER_SEC, &rem);
-	value->tv_usec = rem / NSEC_PER_USEC;
-}
-
-#undef TASK_SIZE
-#define TASK_SIZE TASK_SIZE32
-
 #undef ns_to_kernel_old_timeval
 #define ns_to_kernel_old_timeval ns_to_old_timeval32
 

From fd624c712dfcb6bd6d34018bf879cb4fc6ef84f9 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Sat, 13 Jun 2020 23:33:11 -0400
Subject: [PATCH 07/13] mips: KVM_GUEST makes no sense for 64bit builds...

it's always been about MIPS32

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 arch/mips/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 0a17bedf4f0d..04aecf51e376 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -2182,7 +2182,7 @@ endchoice
 config KVM_GUEST
 	bool "KVM Guest Kernel"
 	depends on CPU_MIPS32_R2
-	depends on BROKEN_ON_SMP
+	depends on !64BIT && BROKEN_ON_SMP
 	help
 	  Select this option if building a guest kernel for KVM (Trap & Emulate)
 	  mode.

From 056f280f3b63f68073dd8d332bf2a0132deccd82 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Sat, 13 Jun 2020 23:37:24 -0400
Subject: [PATCH 08/13] mips compat: don't bother with ELF_ET_DYN_BASE

normal mips one is just fine - it's only used after we'd done
SET_PERSONALITY2() and by that point TASK_SIZE will yield the
right value

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 arch/mips/include/asm/elf.h      | 2 --
 arch/mips/kernel/binfmt_elfn32.c | 4 ----
 arch/mips/kernel/binfmt_elfo32.c | 8 --------
 3 files changed, 14 deletions(-)

diff --git a/arch/mips/include/asm/elf.h b/arch/mips/include/asm/elf.h
index 71c7622025d1..d29e43e4f9b1 100644
--- a/arch/mips/include/asm/elf.h
+++ b/arch/mips/include/asm/elf.h
@@ -469,9 +469,7 @@ extern const char *__elf_base_platform;
    the loader.	We need to make sure that it is out of the way of the program
    that it will "exec", and that there is sufficient room for the brk.	*/
 
-#ifndef ELF_ET_DYN_BASE
 #define ELF_ET_DYN_BASE		(TASK_SIZE / 3 * 2)
-#endif
 
 /* update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT entries changes */
 #define ARCH_DLINFO							\
diff --git a/arch/mips/kernel/binfmt_elfn32.c b/arch/mips/kernel/binfmt_elfn32.c
index 4c5544ae8fa4..08bc05fd9882 100644
--- a/arch/mips/kernel/binfmt_elfn32.c
+++ b/arch/mips/kernel/binfmt_elfn32.c
@@ -34,10 +34,6 @@ typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
  */
 #define elf_check_arch elfn32_check_arch
 
-#define TASK32_SIZE		0x7fff8000UL
-#undef ELF_ET_DYN_BASE
-#define ELF_ET_DYN_BASE		(TASK32_SIZE / 3 * 2)
-
 #include <asm/processor.h>
 #include <linux/elfcore.h>
 #include <linux/compat.h>
diff --git a/arch/mips/kernel/binfmt_elfo32.c b/arch/mips/kernel/binfmt_elfo32.c
index 6ba7501e7079..f5ee6b43b49c 100644
--- a/arch/mips/kernel/binfmt_elfo32.c
+++ b/arch/mips/kernel/binfmt_elfo32.c
@@ -34,14 +34,6 @@ typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
  */
 #define elf_check_arch elfo32_check_arch
 
-#ifdef CONFIG_KVM_GUEST
-#define TASK32_SIZE		0x3fff8000UL
-#else
-#define TASK32_SIZE		0x7fff8000UL
-#endif
-#undef ELF_ET_DYN_BASE
-#define ELF_ET_DYN_BASE		(TASK32_SIZE / 3 * 2)
-
 #include <asm/processor.h>
 
 #include <linux/elfcore.h>

From 2fb33bec053b01e616fab921aab4d4775d374e8f Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Sat, 13 Jun 2020 23:42:04 -0400
Subject: [PATCH 09/13] mips: don't bother with ELF_CORE_EFLAGS

mips coredumps are regset-based, so ELF_CORE_EFLAGS is not used at all -
user_..._view.e_flags is.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 arch/mips/kernel/binfmt_elfn32.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/mips/kernel/binfmt_elfn32.c b/arch/mips/kernel/binfmt_elfn32.c
index 08bc05fd9882..573f2a177da6 100644
--- a/arch/mips/kernel/binfmt_elfn32.c
+++ b/arch/mips/kernel/binfmt_elfn32.c
@@ -52,8 +52,6 @@ struct elf_prstatus32
 
 #define init_elf_binfmt init_elfn32_binfmt
 
-#define ELF_CORE_EFLAGS EF_MIPS_ABI2
-
 #undef ns_to_kernel_old_timeval
 #define ns_to_kernel_old_timeval ns_to_old_timeval32
 

From 0bb87f051e4282afb5f472807c7244b21cf515c7 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Sun, 14 Jun 2020 00:18:12 -0400
Subject: [PATCH 10/13] mips compat: switch to compat_binfmt_elf.c

Like amd64, mips has two 32bit ABIs - o32 and n32.  Unlike amd64,
it does not use compat_binfmt_elf.c for either of those; each
of those ABIs has a binfmt handler of its own, both very similar
to fs/compat_binfmt_elf.c.  And the same technics as we use on
amd64 can be used to make fs/compat_binfmt_elf.c handle both.
	* merge elfo32_check_arch() with elfn32_check_arch(),
make that serve as compat_elf_check_arch().  Note that
SET_PERSONALITY2() is already the same for all ABI variants -
it looks at the elf header to choose the flags to set.
	* add asm/elfcore-compat.h, using the bigger (n32) variant
of elf32_prstatus as compat_elf_prstatus there.
	* make PRSTATUS_SIZE() and SET_PR_FPVALID() choose the
right layout, same as done for amd64.  test_thread_flag(TIF_32BIT_REGS)
is used as the predicate.

Voila - we are rid of binfmt_elf{n,o}32.c; fs/compat_binfmt_elf.c is
used, same as for all other ELF-supporting 64bit architectures that
need 32bit compat.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 arch/mips/Kconfig                      |  8 ++--
 arch/mips/include/asm/elf.h            | 54 ++++++++-------------
 arch/mips/include/asm/elfcore-compat.h | 29 +++++++++++
 arch/mips/kernel/Makefile              |  4 +-
 arch/mips/kernel/binfmt_elfn32.c       | 65 -------------------------
 arch/mips/kernel/binfmt_elfo32.c       | 66 --------------------------
 arch/mips/kernel/scall64-n64.S         |  2 +-
 7 files changed, 54 insertions(+), 174 deletions(-)
 create mode 100644 arch/mips/include/asm/elfcore-compat.h
 delete mode 100644 arch/mips/kernel/binfmt_elfn32.c
 delete mode 100644 arch/mips/kernel/binfmt_elfo32.c

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 04aecf51e376..a46423f1cabc 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -92,6 +92,7 @@ config MIPS
 	select SET_FS
 	select SYSCTL_EXCEPTION_TRACE
 	select VIRT_TO_BUS
+	select ARCH_HAS_ELFCORE_COMPAT
 
 config MIPS_FIXUP_BIGPHYS_ADDR
 	bool
@@ -3277,6 +3278,7 @@ config MIPS32_O32
 	select ARCH_WANT_OLD_COMPAT_IPC
 	select COMPAT
 	select MIPS32_COMPAT
+	select COMPAT_BINFMT_ELF
 	select SYSVIPC_COMPAT if SYSVIPC
 	help
 	  Select this option if you want to run o32 binaries.  These are pure
@@ -3290,6 +3292,7 @@ config MIPS32_N32
 	depends on 64BIT
 	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
 	select COMPAT
+	select COMPAT_BINFMT_ELF
 	select MIPS32_COMPAT
 	select SYSVIPC_COMPAT if SYSVIPC
 	help
@@ -3300,11 +3303,6 @@ config MIPS32_N32
 
 	  If unsure, say N.
 
-config BINFMT_ELF32
-	bool
-	default y if MIPS32_O32 || MIPS32_N32
-	select ELFCORE
-
 menu "Power management options"
 
 config ARCH_HIBERNATION_POSSIBLE
diff --git a/arch/mips/include/asm/elf.h b/arch/mips/include/asm/elf.h
index d29e43e4f9b1..dc8d2863752c 100644
--- a/arch/mips/include/asm/elf.h
+++ b/arch/mips/include/asm/elf.h
@@ -201,7 +201,6 @@ struct mips_elf_abiflags_v0 {
 	uint32_t flags2;
 };
 
-#ifndef ELF_ARCH
 /* ELF register definitions */
 #define ELF_NGREG	45
 #define ELF_NFPREG	33
@@ -219,7 +218,7 @@ void mips_dump_regs64(u64 *uregs, const struct pt_regs *regs);
 /*
  * This is used to ensure we don't load something for the wrong architecture.
  */
-#define elf_check_arch elfo32_check_arch
+#define elf_check_arch elf32_check_arch
 
 /*
  * These are used to set parameters in the core dumps.
@@ -235,7 +234,8 @@ void mips_dump_regs64(u64 *uregs, const struct pt_regs *regs);
 /*
  * This is used to ensure we don't load something for the wrong architecture.
  */
-#define elf_check_arch elfn64_check_arch
+#define elf_check_arch elf64_check_arch
+#define compat_elf_check_arch elf32_check_arch
 
 /*
  * These are used to set parameters in the core dumps.
@@ -257,8 +257,6 @@ void mips_dump_regs64(u64 *uregs, const struct pt_regs *regs);
 #endif
 #define ELF_ARCH	EM_MIPS
 
-#endif /* !defined(ELF_ARCH) */
-
 /*
  * In order to be sure that we don't attempt to execute an O32 binary which
  * requires 64 bit FP (FR=1) on a system which does not support it we refuse
@@ -277,9 +275,9 @@ void mips_dump_regs64(u64 *uregs, const struct pt_regs *regs);
 #define vmcore_elf64_check_arch mips_elf_check_machine
 
 /*
- * Return non-zero if HDR identifies an o32 ELF binary.
+ * Return non-zero if HDR identifies an o32 or n32 ELF binary.
  */
-#define elfo32_check_arch(hdr)						\
+#define elf32_check_arch(hdr)						\
 ({									\
 	int __res = 1;							\
 	struct elfhdr *__h = (hdr);					\
@@ -288,21 +286,26 @@ void mips_dump_regs64(u64 *uregs, const struct pt_regs *regs);
 		__res = 0;						\
 	if (__h->e_ident[EI_CLASS] != ELFCLASS32)			\
 		__res = 0;						\
-	if ((__h->e_flags & EF_MIPS_ABI2) != 0)				\
-		__res = 0;						\
-	if (((__h->e_flags & EF_MIPS_ABI) != 0) &&			\
-	    ((__h->e_flags & EF_MIPS_ABI) != EF_MIPS_ABI_O32))		\
-		__res = 0;						\
-	if (__h->e_flags & __MIPS_O32_FP64_MUST_BE_ZERO)		\
-		__res = 0;						\
-									\
+	if ((__h->e_flags & EF_MIPS_ABI2) != 0) {			\
+		if (!IS_ENABLED(CONFIG_MIPS32_N32) ||			\
+		     (__h->e_flags & EF_MIPS_ABI))			\
+			__res = 0;					\
+	} else {							\
+		if (IS_ENABLED(CONFIG_64BIT) && !IS_ENABLED(CONFIG_MIPS32_O32)) \
+			__res = 0;					\
+		if (((__h->e_flags & EF_MIPS_ABI) != 0) &&		\
+		    ((__h->e_flags & EF_MIPS_ABI) != EF_MIPS_ABI_O32))	\
+			__res = 0;					\
+		if (__h->e_flags & __MIPS_O32_FP64_MUST_BE_ZERO)	\
+			__res = 0;					\
+	}								\
 	__res;								\
 })
 
 /*
  * Return non-zero if HDR identifies an n64 ELF binary.
  */
-#define elfn64_check_arch(hdr)						\
+#define elf64_check_arch(hdr)						\
 ({									\
 	int __res = 1;							\
 	struct elfhdr *__h = (hdr);					\
@@ -315,25 +318,6 @@ void mips_dump_regs64(u64 *uregs, const struct pt_regs *regs);
 	__res;								\
 })
 
-/*
- * Return non-zero if HDR identifies an n32 ELF binary.
- */
-#define elfn32_check_arch(hdr)						\
-({									\
-	int __res = 1;							\
-	struct elfhdr *__h = (hdr);					\
-									\
-	if (!mips_elf_check_machine(__h))				\
-		__res = 0;						\
-	if (__h->e_ident[EI_CLASS] != ELFCLASS32)			\
-		__res = 0;						\
-	if (((__h->e_flags & EF_MIPS_ABI2) == 0) ||			\
-	    ((__h->e_flags & EF_MIPS_ABI) != 0))			\
-		__res = 0;						\
-									\
-	__res;								\
-})
-
 struct mips_abi;
 
 extern struct mips_abi mips_abi;
diff --git a/arch/mips/include/asm/elfcore-compat.h b/arch/mips/include/asm/elfcore-compat.h
new file mode 100644
index 000000000000..2f0f0103c75b
--- /dev/null
+++ b/arch/mips/include/asm/elfcore-compat.h
@@ -0,0 +1,29 @@
+#ifndef _ASM_MIPS_ELFCORE_COMPAT_H
+#define _ASM_MIPS_ELFCORE_COMPAT_H
+
+/*
+ * On mips we have two 32bit ABIs - o32 and n32.  The latter
+ * has bigger registers, so we use it for compat_elf_regset_t.
+ * The former uses o32_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 elf_gregset_t compat_elf_gregset_t;
+
+struct o32_elf_prstatus
+{
+	struct compat_elf_prstatus_common	common;
+	unsigned int 			pr_reg[ELF_NGREG];
+	compat_int_t			pr_fpvalid;
+};
+
+#define PRSTATUS_SIZE \
+	(!test_thread_flag(TIF_32BIT_REGS) \
+		? sizeof(struct compat_elf_prstatus) \
+		: sizeof(struct o32_elf_prstatus))
+#define SET_PR_FPVALID(S) \
+	(*(!test_thread_flag(TIF_32BIT_REGS) \
+		? &(S)->pr_fpvalid 	\
+		: &((struct o32_elf_prstatus *)(S))->pr_fpvalid) = 1)
+
+#endif
diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile
index 2a05b923f579..943eaeef73e9 100644
--- a/arch/mips/kernel/Makefile
+++ b/arch/mips/kernel/Makefile
@@ -80,8 +80,8 @@ obj-$(CONFIG_KPROBES)		+= kprobes.o
 obj-$(CONFIG_32BIT)		+= scall32-o32.o
 obj-$(CONFIG_64BIT)		+= scall64-n64.o
 obj-$(CONFIG_MIPS32_COMPAT)	+= linux32.o ptrace32.o signal32.o
-obj-$(CONFIG_MIPS32_N32)	+= binfmt_elfn32.o scall64-n32.o signal_n32.o
-obj-$(CONFIG_MIPS32_O32)	+= binfmt_elfo32.o scall64-o32.o signal_o32.o
+obj-$(CONFIG_MIPS32_N32)	+= scall64-n32.o signal_n32.o
+obj-$(CONFIG_MIPS32_O32)	+= scall64-o32.o signal_o32.o
 
 obj-$(CONFIG_KGDB)		+= kgdb.o
 obj-$(CONFIG_PROC_FS)		+= proc.o
diff --git a/arch/mips/kernel/binfmt_elfn32.c b/arch/mips/kernel/binfmt_elfn32.c
deleted file mode 100644
index 573f2a177da6..000000000000
--- a/arch/mips/kernel/binfmt_elfn32.c
+++ /dev/null
@@ -1,65 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Support for n32 Linux/MIPS ELF binaries.
- * Author: Ralf Baechle (ralf@linux-mips.org)
- *
- * Copyright (C) 1999, 2001 Ralf Baechle
- * Copyright (C) 1999, 2001 Silicon Graphics, Inc.
- *
- * Heavily inspired by the 32-bit Sparc compat code which is
- * Copyright (C) 1995, 1996, 1997, 1998 David S. Miller (davem@redhat.com)
- * Copyright (C) 1995, 1996, 1997, 1998 Jakub Jelinek	(jj@ultra.linux.cz)
- */
-
-#define ELF_ARCH		EM_MIPS
-#define ELF_CLASS		ELFCLASS32
-#ifdef __MIPSEB__
-#define ELF_DATA		ELFDATA2MSB;
-#else /* __MIPSEL__ */
-#define ELF_DATA		ELFDATA2LSB;
-#endif
-
-/* ELF register definitions */
-#define ELF_NGREG	45
-#define ELF_NFPREG	33
-
-typedef unsigned long elf_greg_t;
-typedef elf_greg_t elf_gregset_t[ELF_NGREG];
-
-typedef double elf_fpreg_t;
-typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
-
-/*
- * This is used to ensure we don't load something for the wrong architecture.
- */
-#define elf_check_arch elfn32_check_arch
-
-#include <asm/processor.h>
-#include <linux/elfcore.h>
-#include <linux/compat.h>
-#include <linux/math64.h>
-#include <linux/elfcore-compat.h>
-
-#define elf_prstatus elf_prstatus32
-#define elf_prstatus_common compat_elf_prstatus_common
-struct elf_prstatus32
-{
-	struct compat_elf_prstatus_common common;
-	elf_gregset_t pr_reg;	/* GP registers */
-	int pr_fpvalid;		/* True if math co-processor being used.  */
-};
-#define elf_prpsinfo compat_elf_prpsinfo
-
-#define init_elf_binfmt init_elfn32_binfmt
-
-#undef ns_to_kernel_old_timeval
-#define ns_to_kernel_old_timeval ns_to_old_timeval32
-
-/*
- * Some data types as stored in coredump.
- */
-#define user_long_t             compat_long_t
-#define user_siginfo_t          compat_siginfo_t
-#define copy_siginfo_to_external        copy_siginfo_to_external32
-
-#include "../../../fs/binfmt_elf.c"
diff --git a/arch/mips/kernel/binfmt_elfo32.c b/arch/mips/kernel/binfmt_elfo32.c
deleted file mode 100644
index f5ee6b43b49c..000000000000
--- a/arch/mips/kernel/binfmt_elfo32.c
+++ /dev/null
@@ -1,66 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Support for o32 Linux/MIPS ELF binaries.
- * Author: Ralf Baechle (ralf@linux-mips.org)
- *
- * Copyright (C) 1999, 2001 Ralf Baechle
- * Copyright (C) 1999, 2001 Silicon Graphics, Inc.
- *
- * Heavily inspired by the 32-bit Sparc compat code which is
- * Copyright (C) 1995, 1996, 1997, 1998 David S. Miller (davem@redhat.com)
- * Copyright (C) 1995, 1996, 1997, 1998 Jakub Jelinek	(jj@ultra.linux.cz)
- */
-
-#define ELF_ARCH		EM_MIPS
-#define ELF_CLASS		ELFCLASS32
-#ifdef __MIPSEB__
-#define ELF_DATA		ELFDATA2MSB;
-#else /* __MIPSEL__ */
-#define ELF_DATA		ELFDATA2LSB;
-#endif
-
-/* ELF register definitions */
-#define ELF_NGREG	45
-#define ELF_NFPREG	33
-
-typedef unsigned int elf_greg_t;
-typedef elf_greg_t elf_gregset_t[ELF_NGREG];
-
-typedef double elf_fpreg_t;
-typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
-
-/*
- * This is used to ensure we don't load something for the wrong architecture.
- */
-#define elf_check_arch elfo32_check_arch
-
-#include <asm/processor.h>
-
-#include <linux/elfcore.h>
-#include <linux/compat.h>
-#include <linux/math64.h>
-#include <linux/elfcore-compat.h>
-
-#define elf_prstatus elf_prstatus32
-#define elf_prstatus_common compat_elf_prstatus_common
-struct elf_prstatus32
-{
-	struct compat_elf_prstatus_common common;
-	elf_gregset_t pr_reg;	/* GP registers */
-	int pr_fpvalid;		/* True if math co-processor being used.  */
-};
-#define elf_prpsinfo compat_elf_prpsinfo
-
-#define init_elf_binfmt init_elf32_binfmt
-
-#undef ns_to_kernel_old_timeval
-#define ns_to_kernel_old_timeval ns_to_old_timeval32
-
-/*
- * Some data types as stored in coredump.
- */
-#define user_long_t             compat_long_t
-#define user_siginfo_t          compat_siginfo_t
-#define copy_siginfo_to_external        copy_siginfo_to_external32
-
-#include "../../../fs/binfmt_elf.c"
diff --git a/arch/mips/kernel/scall64-n64.S b/arch/mips/kernel/scall64-n64.S
index 23b2e2b1609c..5e9c497ce099 100644
--- a/arch/mips/kernel/scall64-n64.S
+++ b/arch/mips/kernel/scall64-n64.S
@@ -20,7 +20,7 @@
 #include <asm/unistd.h>
 #include <asm/war.h>
 
-#ifndef CONFIG_BINFMT_ELF32
+#ifndef CONFIG_MIPS32_COMPAT
 /* Neither O32 nor N32, so define handle_sys here */
 #define handle_sys64 handle_sys
 #endif

From 41026c343540e33627e23c8a91ebb679a7c0f89c Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Wed, 2 Dec 2020 23:56:34 -0500
Subject: [PATCH 11/13] Kconfig: regularize selection of CONFIG_BINFMT_ELF

with mips converted to use of fs/config_binfmt_elf.c, there's no
need to keep selects of that thing all over arch/* - we can simply
turn into def_bool y if COMPAT && BINFMT_ELF (in fs/Kconfig.binfmt)
and get rid of all selects.

Several architectures got those selects wrong (e.g. you could
end up with sparc64 sans BINFMT_ELF, with select violating
dependencies, etc.)

Randy Dunlap has spotted some of those; IMO this is simpler than
his fix, but it depends upon the stuff that would need to be
backported, so we might end up using his variant for -stable.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 arch/arm64/Kconfig   | 1 -
 arch/mips/Kconfig    | 2 --
 arch/parisc/Kconfig  | 1 -
 arch/powerpc/Kconfig | 1 -
 arch/s390/Kconfig    | 1 -
 arch/sparc/Kconfig   | 1 -
 arch/x86/Kconfig     | 1 -
 fs/Kconfig.binfmt    | 2 +-
 8 files changed, 1 insertion(+), 9 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 05e17351e4f3..ed48fd42ab33 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1215,7 +1215,6 @@ config ARM64_TAGGED_ADDR_ABI
 menuconfig COMPAT
 	bool "Kernel support for 32-bit EL0"
 	depends on ARM64_4K_PAGES || EXPERT
-	select COMPAT_BINFMT_ELF if BINFMT_ELF
 	select HAVE_UID16
 	select OLD_SIGSUSPEND3
 	select COMPAT_OLD_SIGACTION
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index a46423f1cabc..f29ec95e3458 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -3278,7 +3278,6 @@ config MIPS32_O32
 	select ARCH_WANT_OLD_COMPAT_IPC
 	select COMPAT
 	select MIPS32_COMPAT
-	select COMPAT_BINFMT_ELF
 	select SYSVIPC_COMPAT if SYSVIPC
 	help
 	  Select this option if you want to run o32 binaries.  These are pure
@@ -3292,7 +3291,6 @@ config MIPS32_N32
 	depends on 64BIT
 	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
 	select COMPAT
-	select COMPAT_BINFMT_ELF
 	select MIPS32_COMPAT
 	select SYSVIPC_COMPAT if SYSVIPC
 	help
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 78b17621ee4a..26daf57b9df6 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -336,7 +336,6 @@ source "kernel/Kconfig.hz"
 config COMPAT
 	def_bool y
 	depends on 64BIT
-	select COMPAT_BINFMT_ELF if BINFMT_ELF
 
 config SYSVIPC_COMPAT
 	def_bool y
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 107bb4319e0e..d26a89cd8908 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -282,7 +282,6 @@ config COMPAT
 	bool "Enable support for 32bit binaries"
 	depends on PPC64
 	default y if !CPU_LITTLE_ENDIAN
-	select COMPAT_BINFMT_ELF
 	select ARCH_WANT_OLD_COMPAT_IPC
 	select COMPAT_OLD_SIGACTION
 
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index e84bdd15150b..73b61fe7231e 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -423,7 +423,6 @@ config 64BIT
 config COMPAT
 	def_bool y
 	prompt "Kernel support for 31 bit emulation"
-	select COMPAT_BINFMT_ELF if BINFMT_ELF
 	select ARCH_WANT_OLD_COMPAT_IPC
 	select COMPAT_OLD_SIGACTION
 	select HAVE_UID16
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index c9c34dc52b7d..1a2b5649d267 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -494,7 +494,6 @@ config COMPAT
 	bool
 	depends on SPARC64
 	default y
-	select COMPAT_BINFMT_ELF
 	select HAVE_UID16
 	select ARCH_WANT_OLD_COMPAT_IPC
 	select COMPAT_OLD_SIGACTION
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index a2182d22b5fa..6d130d1c440b 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2899,7 +2899,6 @@ config COMPAT_32
 config COMPAT
 	def_bool y
 	depends on IA32_EMULATION || X86_X32
-	select COMPAT_BINFMT_ELF if BINFMT_ELF
 
 if COMPAT
 config COMPAT_FOR_U64_ALIGNMENT
diff --git a/fs/Kconfig.binfmt b/fs/Kconfig.binfmt
index 885da6d983b4..b32f5df68ae9 100644
--- a/fs/Kconfig.binfmt
+++ b/fs/Kconfig.binfmt
@@ -29,7 +29,7 @@ config BINFMT_ELF
 	  latest version).
 
 config COMPAT_BINFMT_ELF
-	bool
+	def_bool y
 	depends on COMPAT && BINFMT_ELF
 	select ELFCORE
 

From 492ed38192fccb92022b7a6d3b2751a09a3494c6 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Fri, 4 Dec 2020 14:03:08 -0500
Subject: [PATCH 12/13] compat_binfmt_elf: don't bother with undef of ELF_ARCH

It's not used anywhere downstream (and never had been, AFAICS).
Theoretically, fs/binfmt_elf.c does use it, but only in the
non-regset coredump handling and all biarch architectures
end up with that ifdefed out.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/compat_binfmt_elf.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/fs/compat_binfmt_elf.c b/fs/compat_binfmt_elf.c
index a6321415aba0..e40bdbdc094f 100644
--- a/fs/compat_binfmt_elf.c
+++ b/fs/compat_binfmt_elf.c
@@ -62,7 +62,6 @@
  * differ from the native ones, or omitted when they match.
  */
 
-#undef	ELF_ARCH
 #undef	elf_check_arch
 #define	elf_check_arch	compat_elf_check_arch
 

From e565d89e4aa07e3f20ac5e8757b1da24b5878e69 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Fri, 4 Dec 2020 14:06:04 -0500
Subject: [PATCH 13/13] get rid of COMPAT_ELF_EXEC_PAGESIZE

not defined by any architecture (and never had been)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/compat_binfmt_elf.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/fs/compat_binfmt_elf.c b/fs/compat_binfmt_elf.c
index e40bdbdc094f..95e72d271b95 100644
--- a/fs/compat_binfmt_elf.c
+++ b/fs/compat_binfmt_elf.c
@@ -90,11 +90,6 @@
 #define	ELF_ET_DYN_BASE		COMPAT_ELF_ET_DYN_BASE
 #endif
 
-#ifdef COMPAT_ELF_EXEC_PAGESIZE
-#undef	ELF_EXEC_PAGESIZE
-#define	ELF_EXEC_PAGESIZE	COMPAT_ELF_EXEC_PAGESIZE
-#endif
-
 #ifdef	COMPAT_ELF_PLAT_INIT
 #undef	ELF_PLAT_INIT
 #define	ELF_PLAT_INIT		COMPAT_ELF_PLAT_INIT