Fix sys/procfs.h pr_uid, pr_gid type (bug 23649)

Discussion:

Joseph Myers

2018-09-13 20:49:29 UTC

As noted in
<https://sourceware.org/ml/libc-alpha/2018-09/msg00178.html>, glibc's
sys/procfs.h headers for microblaze, mips (n64), nios2 and riscv have
incorrect types for the pr_uid and pr_gid members of struct
elf_prpsinfo (as does the generic Linux version, but nothing uses
that).

This patch fixes those headers to use unsigned int. The generic Linux
version is also fixed, but I do *not* recommend making new
architectures use it yet. Rather, I think it should be reworked to
look more like a copy of the AArch64 version, but with a new
<bits/procfs.h> header included to provide register set definitions;
<bits/procfs.h> would then be architecture-specific while many
architectures could use the generic <sys/procfs.h>. This fix is
deliberately separate from any reworking to use a generic header more,
since it's possible there could be uses for backporting this fix but
not for backporting a subsequent cleanup.

Tested with build-many-glibcs.py. This of course doesn't provide much
validation of the structure layout; if the Linux kernel is fixed so
that "#include <linux/elfcore.h>" actually compiles with the headers
from "make headers_install" (and if the layout in both headers is
meant to be the same, whatever ABI we are building for), I have a test
that can be added to glibc to check the layout against that from the
Linux kernel.

2018-09-13 Joseph Myers <***@codesourcery.com>

[BZ #23649]
* sysdeps/unix/sysv/linux/microblaze/sys/procfs.h (struct
elf_prpsinfo): Use unsigned int for pr_uid and pr_gid.
* sysdeps/unix/sysv/linux/mips/sys/procfs.h (struct elf_prpsinfo):
Likewise.
* sysdeps/unix/sysv/linux/nios2/sys/procfs.h (struct
elf_prpsinfo): Likewise.
* sysdeps/unix/sysv/linux/riscv/sys/procfs.h (struct
elf_prpsinfo): Likewise.
* sysdeps/unix/sysv/linux/sys/procfs.h (struct elf_prpsinfo):
Likewise.

diff --git a/sysdeps/unix/sysv/linux/microblaze/sys/procfs.h b/sysdeps/unix/sysv/linux/microblaze/sys/procfs.h
index 17c52519e7..7a9832371e 100644
--- a/sysdeps/unix/sysv/linux/microblaze/sys/procfs.h
+++ b/sysdeps/unix/sysv/linux/microblaze/sys/procfs.h
@@ -91,8 +91,8 @@ struct elf_prpsinfo
char pr_zomb; /* Zombie. */
char pr_nice; /* Nice val. */
unsigned long int pr_flag; /* Flags. */
- unsigned short int pr_uid;
- unsigned short int pr_gid;
+ unsigned int pr_uid;
+ unsigned int pr_gid;
int pr_pid, pr_ppid, pr_pgrp, pr_sid;
/* Lots missing. */
char pr_fname[16]; /* Filename of executable. */
diff --git a/sysdeps/unix/sysv/linux/mips/sys/procfs.h b/sysdeps/unix/sysv/linux/mips/sys/procfs.h
index 2be0c7e818..523317dec7 100644
--- a/sysdeps/unix/sysv/linux/mips/sys/procfs.h
+++ b/sysdeps/unix/sysv/linux/mips/sys/procfs.h
@@ -97,8 +97,8 @@ struct elf_prpsinfo
#else
unsigned long int pr_flag; /* Flags. */
#endif
- long pr_uid;
- long pr_gid;
+ unsigned int pr_uid;
+ unsigned int pr_gid;
int pr_pid, pr_ppid, pr_pgrp, pr_sid;
/* Lots missing */
char pr_fname[16]; /* Filename of executable. */
diff --git a/sysdeps/unix/sysv/linux/nios2/sys/procfs.h b/sysdeps/unix/sysv/linux/nios2/sys/procfs.h
index a61fe96c6b..1bb18f1e58 100644
--- a/sysdeps/unix/sysv/linux/nios2/sys/procfs.h
+++ b/sysdeps/unix/sysv/linux/nios2/sys/procfs.h
@@ -91,8 +91,8 @@ struct elf_prpsinfo
char pr_zomb; /* Zombie. */
char pr_nice; /* Nice val. */
unsigned long int pr_flag; /* Flags. */
- unsigned short int pr_uid;
- unsigned short int pr_gid;
+ unsigned int pr_uid;
+ unsigned int pr_gid;
int pr_pid, pr_ppid, pr_pgrp, pr_sid;
/* Lots missing */
char pr_fname[16]; /* Filename of executable. */
diff --git a/sysdeps/unix/sysv/linux/riscv/sys/procfs.h b/sysdeps/unix/sysv/linux/riscv/sys/procfs.h
index 518de56741..3abbecf957 100644
--- a/sysdeps/unix/sysv/linux/riscv/sys/procfs.h
+++ b/sysdeps/unix/sysv/linux/riscv/sys/procfs.h
@@ -82,8 +82,8 @@ struct elf_prpsinfo
char pr_zomb; /* Zombie. */
char pr_nice; /* Nice val. */
unsigned long int pr_flag; /* Flags. */
- long int pr_uid;
- long int pr_gid;
+ unsigned int pr_uid;
+ unsigned int pr_gid;
int pr_pid, pr_ppid, pr_pgrp, pr_sid;
/* Lots missing */
char pr_fname[16]; /* Filename of executable. */
diff --git a/sysdeps/unix/sysv/linux/sys/procfs.h b/sysdeps/unix/sysv/linux/sys/procfs.h
index 3c417bab29..6af44c02ca 100644
--- a/sysdeps/unix/sysv/linux/sys/procfs.h
+++ b/sysdeps/unix/sysv/linux/sys/procfs.h
@@ -86,8 +86,8 @@ struct elf_prpsinfo
char pr_zomb; /* Zombie. */
char pr_nice; /* Nice val. */
unsigned long int pr_flag; /* Flags. */
- unsigned short int pr_uid;
- unsigned short int pr_gid;
+ unsigned int pr_uid;
+ unsigned int pr_gid;
int pr_pid, pr_ppid, pr_pgrp, pr_sid;
/* Lots missing */
char pr_fname[16]; /* Filename of executable. */

--
Joseph S. Myers
***@codesourcery.com

Florian Weimer

2018-09-14 08:01:09 UTC

Permalink

Post by Joseph Myers
[BZ #23649]
* sysdeps/unix/sysv/linux/microblaze/sys/procfs.h (struct
elf_prpsinfo): Use unsigned int for pr_uid and pr_gid.
Likewise.
* sysdeps/unix/sysv/linux/nios2/sys/procfs.h (struct
elf_prpsinfo): Likewise.
* sysdeps/unix/sysv/linux/riscv/sys/procfs.h (struct
elf_prpsinfo): Likewise.
Likewise.

The changes look okay to me. Does this need a NEWS entry? After all,
the struct size changes with this patch, as far as I can tell.

Thanks,
Florian

Joseph Myers

2018-09-14 13:22:40 UTC

Permalink

The changes look okay to me. Does this need a NEWS entry? After all, the
struct size changes with this patch, as far as I can tell.

I've committed it with the following NEWS entry.

* The type of the pr_uid and pr_gid members of struct elf_prpsinfo, defined
in <sys/procfs.h>, has been corrected to match the type actually used by
the Linux kernel. This affects the size and layout of that structure on
MicroBlaze, MIPS (n64 ABI only), Nios II and RISC-V.

--
Joseph S. Myers
***@codesourcery.com

Florian Weimer

2018-09-14 13:23:41 UTC

Permalink

Post by Joseph Myers

The changes look okay to me. Does this need a NEWS entry? After all, the
struct size changes with this patch, as far as I can tell.

I've committed it with the following NEWS entry.
* The type of the pr_uid and pr_gid members of struct elf_prpsinfo, defined
in <sys/procfs.h>, has been corrected to match the type actually used by
the Linux kernel. This affects the size and layout of that structure on
MicroBlaze, MIPS (n64 ABI only), Nios II and RISC-V.

Thanks, looks good.

Florian

Arnd Bergmann

2018-09-14 11:30:26 UTC

Permalink

Post by Joseph Myers
As noted in
<https://sourceware.org/ml/libc-alpha/2018-09/msg00178.html>, glibc's
sys/procfs.h headers for microblaze, mips (n64), nios2 and riscv have
incorrect types for the pr_uid and pr_gid members of struct
elf_prpsinfo (as does the generic Linux version, but nothing uses
that).
This patch fixes those headers to use unsigned int. The generic Linux
version is also fixed, but I do *not* recommend making new
architectures use it yet. Rather, I think it should be reworked to
look more like a copy of the AArch64 version, but with a new
<bits/procfs.h> header included to provide register set definitions;
<bits/procfs.h> would then be architecture-specific while many
architectures could use the generic <sys/procfs.h>. This fix is
deliberately separate from any reworking to use a generic header more,
since it's possible there could be uses for backporting this fix but
not for backporting a subsequent cleanup.
Tested with build-many-glibcs.py. This of course doesn't provide much
validation of the structure layout; if the Linux kernel is fixed so
that "#include <linux/elfcore.h>" actually compiles with the headers
from "make headers_install" (and if the layout in both headers is
meant to be the same, whatever ABI we are building for), I have a test
that can be added to glibc to check the layout against that from the
Linux kernel.

Looks all good to me, thanks for addressing this!

I've had a look at including linux/elfcore.h from user space,
and what it would take to get it working again. I've got a
prototype patch now (x86 only) that I'll post for futher discussion.

Arnd