Linux-Fsdevel Archive on lore.kernel.org
 help / color / Atom feed
From: Arnd Bergmann <arnd@arndb.de>
To: y2038@lists.linaro.org, Ralf Baechle <ralf@linux-mips.org>,
	Paul Burton <paul.burton@mips.com>,
	James Hogan <jhogan@kernel.org>,
	Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-kernel@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
	Andrew Morton <akpm@linux-foundation.org>,
	Alexey Dobriyan <adobriyan@gmail.com>,
	linux-mips@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: [PATCH 15/23] y2038: elfcore: Use __kernel_old_timeval for process times
Date: Fri,  8 Nov 2019 22:12:14 +0100
Message-ID: <20191108211323.1806194-6-arnd@arndb.de> (raw)
In-Reply-To: <20191108210236.1296047-1-arnd@arndb.de>

We store elapsed time for a crashed process in struct elf_prstatus using
'timeval' structures. Once glibc starts using 64-bit time_t, this becomes
incompatible with the kernel's idea of timeval since the structure layout
no longer matches on 32-bit architectures.

This changes the definition of the elf_prstatus structure to use
__kernel_old_timeval instead, which is hardcoded to the currently used
binary layout. There is no risk of overflow in y2038 though, because
the time values are all relative times, and can store up to 68 years
of process elapsed time.

There is a risk of applications breaking at build time when they
use the new kernel headers and expect the type to be exactly 'timeval'
rather than a structure that has the same fields as before. Those
applications have to be modified to deal with 64-bit time_t anyway.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/mips/kernel/binfmt_elfn32.c |  4 ++--
 arch/mips/kernel/binfmt_elfo32.c |  4 ++--
 fs/binfmt_elf.c                  | 12 ++++++------
 fs/binfmt_elf_fdpic.c            | 12 ++++++------
 fs/compat_binfmt_elf.c           |  4 ++--
 include/uapi/linux/elfcore.h     |  8 ++++----
 6 files changed, 22 insertions(+), 22 deletions(-)

diff --git a/arch/mips/kernel/binfmt_elfn32.c b/arch/mips/kernel/binfmt_elfn32.c
index 7a12763d553a..6ee3f7218c67 100644
--- a/arch/mips/kernel/binfmt_elfn32.c
+++ b/arch/mips/kernel/binfmt_elfn32.c
@@ -100,7 +100,7 @@ jiffies_to_old_timeval32(unsigned long jiffies, struct old_timeval32 *value)
 #undef TASK_SIZE
 #define TASK_SIZE TASK_SIZE32
 
-#undef ns_to_timeval
-#define ns_to_timeval ns_to_old_timeval32
+#undef ns_to_kernel_old_timeval
+#define ns_to_kernel_old_timeval ns_to_old_timeval32
 
 #include "../../../fs/binfmt_elf.c"
diff --git a/arch/mips/kernel/binfmt_elfo32.c b/arch/mips/kernel/binfmt_elfo32.c
index e6db06a1d31a..6dd103d3cebb 100644
--- a/arch/mips/kernel/binfmt_elfo32.c
+++ b/arch/mips/kernel/binfmt_elfo32.c
@@ -103,7 +103,7 @@ jiffies_to_old_timeval32(unsigned long jiffies, struct old_timeval32 *value)
 #undef TASK_SIZE
 #define TASK_SIZE TASK_SIZE32
 
-#undef ns_to_timeval
-#define ns_to_timeval ns_to_old_timeval32
+#undef ns_to_kernel_old_timeval
+#define ns_to_kernel_old_timeval ns_to_old_timeval32
 
 #include "../../../fs/binfmt_elf.c"
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index c5642bcb6b46..5372eabd276a 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1489,18 +1489,18 @@ static void fill_prstatus(struct elf_prstatus *prstatus,
 		 * group-wide total, not its individual thread total.
 		 */
 		thread_group_cputime(p, &cputime);
-		prstatus->pr_utime = ns_to_timeval(cputime.utime);
-		prstatus->pr_stime = ns_to_timeval(cputime.stime);
+		prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime);
+		prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime);
 	} else {
 		u64 utime, stime;
 
 		task_cputime(p, &utime, &stime);
-		prstatus->pr_utime = ns_to_timeval(utime);
-		prstatus->pr_stime = ns_to_timeval(stime);
+		prstatus->pr_utime = ns_to_kernel_old_timeval(utime);
+		prstatus->pr_stime = ns_to_kernel_old_timeval(stime);
 	}
 
-	prstatus->pr_cutime = ns_to_timeval(p->signal->cutime);
-	prstatus->pr_cstime = ns_to_timeval(p->signal->cstime);
+	prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime);
+	prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime);
 }
 
 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index d86ebd0dcc3d..240f66663543 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -1359,17 +1359,17 @@ static void fill_prstatus(struct elf_prstatus *prstatus,
 		 * group-wide total, not its individual thread total.
 		 */
 		thread_group_cputime(p, &cputime);
-		prstatus->pr_utime = ns_to_timeval(cputime.utime);
-		prstatus->pr_stime = ns_to_timeval(cputime.stime);
+		prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime);
+		prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime);
 	} else {
 		u64 utime, stime;
 
 		task_cputime(p, &utime, &stime);
-		prstatus->pr_utime = ns_to_timeval(utime);
-		prstatus->pr_stime = ns_to_timeval(stime);
+		prstatus->pr_utime = ns_to_kernel_old_timeval(utime);
+		prstatus->pr_stime = ns_to_kernel_old_timeval(stime);
 	}
-	prstatus->pr_cutime = ns_to_timeval(p->signal->cutime);
-	prstatus->pr_cstime = ns_to_timeval(p->signal->cstime);
+	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;
diff --git a/fs/compat_binfmt_elf.c b/fs/compat_binfmt_elf.c
index b7f9ffa1d5f1..aaad4ca1217e 100644
--- a/fs/compat_binfmt_elf.c
+++ b/fs/compat_binfmt_elf.c
@@ -48,8 +48,8 @@
 #define elf_prstatus	compat_elf_prstatus
 #define elf_prpsinfo	compat_elf_prpsinfo
 
-#undef ns_to_timeval
-#define ns_to_timeval ns_to_old_timeval32
+#undef ns_to_kernel_old_timeval
+#define ns_to_kernel_old_timeval ns_to_old_timeval32
 
 /*
  * To use this file, asm/elf.h must define compat_elf_check_arch.
diff --git a/include/uapi/linux/elfcore.h b/include/uapi/linux/elfcore.h
index 0b2c9e16e345..baf03562306d 100644
--- a/include/uapi/linux/elfcore.h
+++ b/include/uapi/linux/elfcore.h
@@ -53,10 +53,10 @@ struct elf_prstatus
 	pid_t	pr_ppid;
 	pid_t	pr_pgrp;
 	pid_t	pr_sid;
-	struct timeval pr_utime;	/* User time */
-	struct timeval pr_stime;	/* System time */
-	struct timeval pr_cutime;	/* Cumulative user time */
-	struct timeval pr_cstime;	/* Cumulative system time */
+	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 */
 #if 0
 	long	pr_instr;		/* Current instruction */
 #endif
-- 
2.20.0


  parent reply index

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-08 21:02 [PATCH 00/23] y2038 cleanups Arnd Bergmann
2019-11-08 21:07 ` [PATCH 01/23] y2038: remove CONFIG_64BIT_TIME Arnd Bergmann
2019-11-20 22:28   ` [Y2038] " Ben Hutchings
2019-11-20 22:58     ` Dmitry Safonov
2019-11-08 21:12 ` [PATCH 12/23] y2038: syscalls: change remaining timeval to __kernel_old_timeval Arnd Bergmann
2019-11-11 12:44   ` Christian Brauner
2019-11-13 22:39   ` Rafael J. Wysocki
2019-11-08 21:12 ` Arnd Bergmann [this message]
2019-11-08 21:12 ` [PATCH 16/23] y2038: timerfd: Use timespec64 internally Arnd Bergmann
2019-11-13 21:49   ` Thomas Gleixner
2019-11-13 21:40 ` [PATCH 00/23] y2038 cleanups Arnd Bergmann

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20191108211323.1806194-6-arnd@arndb.de \
    --to=arnd@arndb.de \
    --cc=adobriyan@gmail.com \
    --cc=akpm@linux-foundation.org \
    --cc=jhogan@kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mips@vger.kernel.org \
    --cc=paul.burton@mips.com \
    --cc=ralf@linux-mips.org \
    --cc=viro@zeniv.linux.org.uk \
    --cc=y2038@lists.linaro.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-Fsdevel Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-fsdevel/0 linux-fsdevel/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-fsdevel linux-fsdevel/ https://lore.kernel.org/linux-fsdevel \
		linux-fsdevel@vger.kernel.org
	public-inbox-index linux-fsdevel

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-fsdevel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git