user/sven/linux.git/include/linux/kexec.h, branch v4.7

s390/kexec: consolidate crash_map/unmap_reserved_pages() and arch_kexec_protect(unprotect)_crashkres()

2016-05-24T00:04:14Z

Commit 3f625002581b ("kexec: introduce a protection mechanism for the crashkernel reserved memory") is a similar mechanism for protecting the crash kernel reserved memory to previous crash_map/unmap_reserved_pages() implementation, the new one is more generic in name and cleaner in code (besides, some arch may not be allowed to unmap the pgtable). Therefore, this patch consolidates them, and uses the new arch_kexec_protect(unprotect)_crashkres() to replace former crash_map/unmap_reserved_pages() which by now has been only used by S390. The consolidation work needs the crash memory to be mapped initially, this is done in machine_kdump_pm_init() which is after reserve_crashkernel(). Once kdump kernel is loaded, the new arch_kexec_protect_crashkres() implemented for S390 will actually unmap the pgtable like before. Signed-off-by: Xunlei Pang Signed-off-by: Michael Holzheu Acked-by: Michael Holzheu Cc: Heiko Carstens Cc: "Eric W. Biederman" Cc: Minfei Huang Cc: Vivek Goyal Cc: Dave Young Cc: Baoquan He Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kexec: introduce a protection mechanism for the crashkernel reserved memory

2016-05-24T00:04:14Z

For the cases that some kernel (module) path stamps the crash reserved memory(already mapped by the kernel) where has been loaded the second kernel data, the kdump kernel will probably fail to boot when panic happens (or even not happens) leaving the culprit at large, this is unacceptable. The patch introduces a mechanism for detecting such cases: 1) After each crash kexec loading, it simply marks the reserved memory regions readonly since we no longer access it after that. When someone stamps the region, the first kernel will panic and trigger the kdump. The weak arch_kexec_protect_crashkres() is introduced to do the actual protection. 2) To allow multiple loading, once 1) was done we also need to remark the reserved memory to readwrite each time a system call related to kdump is made. The weak arch_kexec_unprotect_crashkres() is introduced to do the actual protection. The architecture can make its specific implementation by overriding arch_kexec_protect_crashkres() and arch_kexec_unprotect_crashkres(). Signed-off-by: Xunlei Pang Cc: Eric Biederman Cc: Dave Young Cc: Minfei Huang Cc: Vivek Goyal Cc: Baoquan He Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kexec: move some memembers and definitions within the scope of CONFIG_KEXEC_FILE

2016-01-21T01:09:18Z

Move the stuff currently only used by the kexec file code within CONFIG_KEXEC_FILE (and CONFIG_KEXEC_VERIFY_SIG). Also move internal "struct kexec_sha_region" and "struct kexec_buf" into "kexec_internal.h". Signed-off-by: Xunlei Pang Cc: "Eric W. Biederman" Cc: Dave Young Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kexec: Fix race between panic() and crash_kexec()

2015-12-19T10:07:01Z

Currently, panic() and crash_kexec() can be called at the same time. For example (x86 case): CPU 0: oops_end() crash_kexec() mutex_trylock() // acquired nmi_shootdown_cpus() // stop other CPUs CPU 1: panic() crash_kexec() mutex_trylock() // failed to acquire smp_send_stop() // stop other CPUs infinite loop If CPU 1 calls smp_send_stop() before nmi_shootdown_cpus(), kdump fails. In another case: CPU 0: oops_end() crash_kexec() mutex_trylock() // acquired io_check_error() panic() crash_kexec() mutex_trylock() // failed to acquire infinite loop Clearly, this is an undesirable result. To fix this problem, this patch changes crash_kexec() to exclude others by using the panic_cpu atomic. Signed-off-by: Hidehiro Kawai Acked-by: Michal Hocko Cc: Andrew Morton Cc: Baoquan He Cc: Dave Young Cc: "Eric W. Biederman" Cc: HATAYAMA Daisuke Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Jonathan Corbet Cc: kexec@lists.infradead.org Cc: linux-doc@vger.kernel.org Cc: Martin Schwidefsky Cc: Masami Hiramatsu Cc: Minfei Huang Cc: Peter Zijlstra Cc: Seth Jennings Cc: Steven Rostedt Cc: Thomas Gleixner Cc: Vitaly Kuznetsov Cc: Vivek Goyal Cc: x86-ml Link: http://lkml.kernel.org/r/20151210014630.25437.94161.stgit@softrs Signed-off-by: Borislav Petkov Signed-off-by: Thomas Gleixner

kexec: split kexec_load syscall from kexec core code

2015-09-10T20:29:01Z

There are two kexec load syscalls, kexec_load another and kexec_file_load. kexec_file_load has been splited as kernel/kexec_file.c. In this patch I split kexec_load syscall code to kernel/kexec.c. And add a new kconfig option KEXEC_CORE, so we can disable kexec_load and use kexec_file_load only, or vice verse. The original requirement is from Ted Ts'o, he want kexec kernel signature being checked with CONFIG_KEXEC_VERIFY_SIG enabled. But kexec-tools use kexec_load syscall can bypass the checking. Vivek Goyal proposed to create a common kconfig option so user can compile in only one syscall for loading kexec kernel. KEXEC/KEXEC_FILE selects KEXEC_CORE so that old config files still work. Because there's general code need CONFIG_KEXEC_CORE, so I updated all the architecture Kconfig with a new option KEXEC_CORE, and let KEXEC selects KEXEC_CORE in arch Kconfig. Also updated general kernel code with to kexec_load syscall. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Dave Young Cc: Eric W. Biederman Cc: Vivek Goyal Cc: Petr Tesarik Cc: Theodore Ts'o Cc: Josh Boyer Cc: David Howells Cc: Geert Uytterhoeven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kexec: split kexec_file syscall code to kexec_file.c

2015-09-10T20:29:01Z

Split kexec_file syscall related code to another file kernel/kexec_file.c so that the #ifdef CONFIG_KEXEC_FILE in kexec.c can be dropped. Sharing variables and functions are moved to kernel/kexec_internal.h per suggestion from Vivek and Petr. [akpm@linux-foundation.org: fix bisectability] [akpm@linux-foundation.org: declare the various arch_kexec functions] [akpm@linux-foundation.org: fix build] Signed-off-by: Dave Young Cc: Eric W. Biederman Cc: Vivek Goyal Cc: Petr Tesarik Cc: Theodore Ts'o Cc: Josh Boyer Cc: David Howells Cc: Geert Uytterhoeven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kexec: define kexec_in_progress in !CONFIG_KEXEC case

2015-08-05T05:25:28Z

If some piece of code wants to check kexec_in_progress it has to be put in #ifdef CONFIG_KEXEC block to not break the build in !CONFIG_KEXEC case. Overcome this limitation by defining kexec_in_progress to false. Signed-off-by: Vitaly Kuznetsov Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

kexec: allocate the kexec control page with KEXEC_CONTROL_MEMORY_GFP

2015-04-23T14:52:01Z

Introduce KEXEC_CONTROL_MEMORY_GFP to allow the architecture code to override the gfp flags of the allocation for the kexec control page. The loop in kimage_alloc_normal_control_pages allocates pages with GFP_KERNEL until a page is found that happens to have an address smaller than the KEXEC_CONTROL_MEMORY_LIMIT. On systems with a large memory size but a small KEXEC_CONTROL_MEMORY_LIMIT the loop will keep allocating memory until the oom killer steps in. Signed-off-by: Martin Schwidefsky

kexec: add IND_FLAGS macro

2015-02-17T22:34:51Z

Add a new kexec preprocessor macro IND_FLAGS, which is the bitwise OR of all the possible kexec IND_ kimage_entry indirection flags. Having this macro allows for simplified code in the prosessing of the kexec kimage_entry items. Also, remove the local powerpc definition and use the generic one. Signed-off-by: Geoff Levand Acked-by: Benjamin Herrenschmidt Acked-by: Vivek Goyal Cc: Arnd Bergmann Cc: Maximilian Attems Cc: Michal Marek Cc: H. Peter Anvin Cc: Paul Bolle Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kexec: add bit definitions for kimage entry flags

2015-02-17T22:34:51Z

Define new kexec preprocessor macros IND_*_BIT that define the bit position of the kimage entry flags. Change the existing IND_* flag macros to be defined as bit shifts of the corresponding IND_*_BIT macros. Also wrap all C language code in kexec.h with #if !defined(__ASSEMBLY__) so assembly files can include kexec.h to get the IND_* and IND_*_BIT macros. Some CPU instruction sets have tests for bit position which are convenient in implementing routines that operate on the kimage entry list. The addition of these bit position macros in a common location will avoid duplicate definitions and the chance that changes to the IND_* flags will not be propagated to assembly files. Signed-off-by: Geoff Levand Acked-by: Vivek Goyal Cc: Arnd Bergmann Cc: Benjamin Herrenschmidt Cc: H. Peter Anvin Cc: Maximilian Attems Cc: Michal Marek Cc: Paul Bolle Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds