diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.9.21/0047-fs-proc-Report-eip-esp-in-prod-PID-stat-for-coredump.patch')
| -rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.9.21/0047-fs-proc-Report-eip-esp-in-prod-PID-stat-for-coredump.patch | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0047-fs-proc-Report-eip-esp-in-prod-PID-stat-for-coredump.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0047-fs-proc-Report-eip-esp-in-prod-PID-stat-for-coredump.patch new file mode 100644 index 00000000..6f74166c --- /dev/null +++ b/common/recipes-kernel/linux/linux-yocto-4.9.21/0047-fs-proc-Report-eip-esp-in-prod-PID-stat-for-coredump.patch @@ -0,0 +1,77 @@ +From 10f154142e83fdb4e9d107e0f72b01864e69e108 Mon Sep 17 00:00:00 2001 +From: John Ogness <john.ogness@linutronix.de> +Date: Thu, 14 Sep 2017 11:42:17 +0200 +Subject: [PATCH 47/93] fs/proc: Report eip/esp in /prod/PID/stat for + coredumping + +commit fd7d56270b526ca3ed0c224362e3c64a0f86687a upstream. + +Commit 0a1eb2d474ed ("fs/proc: Stop reporting eip and esp in +/proc/PID/stat") stopped reporting eip/esp because it is +racy and dangerous for executing tasks. The comment adds: + + As far as I know, there are no use programs that make any + material use of these fields, so just get rid of them. + +However, existing userspace core-dump-handler applications (for +example, minicoredumper) are using these fields since they +provide an excellent cross-platform interface to these valuable +pointers. So that commit introduced a user space visible +regression. + +Partially revert the change and make the readout possible for +tasks with the proper permissions and only if the target task +has the PF_DUMPCORE flag set. + +Fixes: 0a1eb2d474ed ("fs/proc: Stop reporting eip and esp in> /proc/PID/stat") +Reported-by: Marco Felsch <marco.felsch@preh.de> +Signed-off-by: John Ogness <john.ogness@linutronix.de> +Reviewed-by: Andy Lutomirski <luto@kernel.org> +Cc: Tycho Andersen <tycho.andersen@canonical.com> +Cc: Kees Cook <keescook@chromium.org> +Cc: Peter Zijlstra <peterz@infradead.org> +Cc: Brian Gerst <brgerst@gmail.com> +Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> +Cc: Borislav Petkov <bp@alien8.de> +Cc: Al Viro <viro@zeniv.linux.org.uk> +Cc: Linux API <linux-api@vger.kernel.org> +Cc: Andrew Morton <akpm@linux-foundation.org> +Cc: Linus Torvalds <torvalds@linux-foundation.org> +Link: http://lkml.kernel.org/r/87poatfwg6.fsf@linutronix.de +Signed-off-by: Thomas Gleixner <tglx@linutronix.de> +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +--- + fs/proc/array.c | 9 +++++++++ + 1 file changed, 9 insertions(+) + +diff --git a/fs/proc/array.c b/fs/proc/array.c +index 81818ad..c932ec4 100644 +--- a/fs/proc/array.c ++++ b/fs/proc/array.c +@@ -60,6 +60,7 @@ + #include <linux/tty.h> + #include <linux/string.h> + #include <linux/mman.h> ++#include <linux/sched.h> + #include <linux/proc_fs.h> + #include <linux/ioport.h> + #include <linux/uaccess.h> +@@ -416,7 +417,15 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns, + * esp and eip are intentionally zeroed out. There is no + * non-racy way to read them without freezing the task. + * Programs that need reliable values can use ptrace(2). ++ * ++ * The only exception is if the task is core dumping because ++ * a program is not able to use ptrace(2) in that case. It is ++ * safe because the task has stopped executing permanently. + */ ++ if (permitted && (task->flags & PF_DUMPCORE)) { ++ eip = KSTK_EIP(task); ++ esp = KSTK_ESP(task); ++ } + } + + get_task_comm(tcomm, task); +-- +2.7.4 + |