[PATCH v2 1/3] kexec_load: Use new kexec flag for hotplug support
Sourabh Jain
sourabhjain at linux.ibm.com
Tue Jun 25 22:19:18 PDT 2024
Hello Baoquan,
On 26/06/24 09:20, Baoquan He wrote:
> On 06/25/24 at 01:51pm, Sourabh Jain wrote:
>> Any review/comments on this patch series.
> I try to have a look, while there's conflict when applying to the latest
> kexec-tools.
This patch series apply cleanly on master branch of below repos.
https://git.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git/
https://github.com/horms/kexec-tools
May I know which upstream repo and branch you are applying this patch
series?
Thanks,
Sourabh Jain
>
>> On 14/06/24 00:37, Sourabh Jain wrote:
>>> Kernel commit 79365026f869 (crash: add a new kexec flag for hotplug
>>> support) has introduced a new kexec flag to generalize hotplug support.
>>> The newly introduced kexec flags for hotplug allow architectures to
>>> exclude all the required kexec segments from SHA calculation so that
>>> the kernel can update them on hotplug events. This was not possible
>>> earlier with the KEXEC_UPDATE_ELFCOREHDR kexec flags since it was added
>>> only for the elfcorehdr segment.
>>>
>>> To enable architectures to control the list of kexec segments to exclude
>>> when hotplug support is enabled, add a new architecture-specific
>>> function named arch_do_exclude_segment. During the SHA calculation, this
>>> function gets called to let the architecture decide whether a specific
>>> kexec segment should be considered for SHA calculation or not.
>>>
>>> Given that the KEXEC_UPDATE_ELFCOREHDR is no longer required and was
>>> colliding with the KEXEC_LIVE_UPDATE update flag, it is removed.
>>>
>>> Cc: Aditya Gupta <adityag at linux.ibm.com>
>>> Cc: Baoquan He <bhe at redhat.com>
>>> Cc: Coiby Xu <coxu at redhat.com>
>>> Cc: Mahesh Salgaonkar <mahesh at linux.ibm.com>
>>> Cc: Simon Horman <horms at kernel.org>
>>> Acked-by: Hari Bathini <hbathini at linux.ibm.com>
>>> Signed-off-by: Sourabh Jain <sourabhjain at linux.ibm.com>
>>> ---
>>>
>>> * No changes in v2.
>>>
>>> ---
>>> kexec/arch/arm/kexec-arm.c | 5 +++++
>>> kexec/arch/arm64/kexec-arm64.c | 4 ++++
>>> kexec/arch/cris/kexec-cris.c | 4 ++++
>>> kexec/arch/hppa/kexec-hppa.c | 5 +++++
>>> kexec/arch/i386/kexec-x86.c | 8 ++++++++
>>> kexec/arch/ia64/kexec-ia64.c | 4 ++++
>>> kexec/arch/loongarch/kexec-loongarch.c | 5 +++++
>>> kexec/arch/m68k/kexec-m68k.c | 5 +++++
>>> kexec/arch/mips/kexec-mips.c | 4 ++++
>>> kexec/arch/ppc/kexec-ppc.c | 4 ++++
>>> kexec/arch/ppc64/kexec-ppc64.c | 5 +++++
>>> kexec/arch/s390/kexec-s390.c | 5 +++++
>>> kexec/arch/sh/kexec-sh.c | 5 +++++
>>> kexec/arch/x86_64/kexec-x86_64.c | 5 +++++
>>> kexec/kexec-syscall.h | 2 +-
>>> kexec/kexec.c | 14 ++++++++------
>>> kexec/kexec.h | 2 ++
>>> 17 files changed, 79 insertions(+), 7 deletions(-)
>>>
>>> diff --git a/kexec/arch/arm/kexec-arm.c b/kexec/arch/arm/kexec-arm.c
>>> index 49f35b1..34531f9 100644
>>> --- a/kexec/arch/arm/kexec-arm.c
>>> +++ b/kexec/arch/arm/kexec-arm.c
>>> @@ -148,3 +148,8 @@ int have_sysfs_fdt(void)
>>> {
>>> return !access(SYSFS_FDT, F_OK);
>>> }
>>> +
>>> +int arch_do_exclude_segment(struct kexec_segment *UNUSED(seg_ptr), struct kexec_info *UNUSED(info))
>>> +{
>>> + return 0;
>>> +}
>>> diff --git a/kexec/arch/arm64/kexec-arm64.c b/kexec/arch/arm64/kexec-arm64.c
>>> index 4a67b0d..9d052b0 100644
>>> --- a/kexec/arch/arm64/kexec-arm64.c
>>> +++ b/kexec/arch/arm64/kexec-arm64.c
>>> @@ -1363,3 +1363,7 @@ void arch_reuse_initrd(void)
>>> void arch_update_purgatory(struct kexec_info *UNUSED(info))
>>> {
>>> }
>>> +int arch_do_exclude_segment(struct kexec_segment *UNUSED(seg_ptr), struct kexec_info *UNUSED(info))
>>> +{
>>> + return 0;
>>> +}
>>> diff --git a/kexec/arch/cris/kexec-cris.c b/kexec/arch/cris/kexec-cris.c
>>> index 3b69709..7f09121 100644
>>> --- a/kexec/arch/cris/kexec-cris.c
>>> +++ b/kexec/arch/cris/kexec-cris.c
>>> @@ -109,3 +109,7 @@ unsigned long add_buffer(struct kexec_info *info, const void *buf,
>>> buf_min, buf_max, buf_end, 1);
>>> }
>>> +int arch_do_exclude_segment(struct kexec_segment *UNUSED(seg_ptr), struct kexec_info *UNUSED(info))
>>> +{
>>> + return 0;
>>> +}
>>> diff --git a/kexec/arch/hppa/kexec-hppa.c b/kexec/arch/hppa/kexec-hppa.c
>>> index 77c9739..a64dc3d 100644
>>> --- a/kexec/arch/hppa/kexec-hppa.c
>>> +++ b/kexec/arch/hppa/kexec-hppa.c
>>> @@ -146,3 +146,8 @@ unsigned long virt_to_phys(unsigned long addr)
>>> {
>>> return addr - phys_offset;
>>> }
>>> +
>>> +int arch_do_exclude_segment(struct kexec_segment *UNUSED(seg_ptr), struct kexec_info *UNUSED(info))
>>> +{
>>> + return 0;
>>> +}
>>> diff --git a/kexec/arch/i386/kexec-x86.c b/kexec/arch/i386/kexec-x86.c
>>> index 444cb69..b4947a0 100644
>>> --- a/kexec/arch/i386/kexec-x86.c
>>> +++ b/kexec/arch/i386/kexec-x86.c
>>> @@ -208,3 +208,11 @@ void arch_update_purgatory(struct kexec_info *info)
>>> elf_rel_set_symbol(&info->rhdr, "panic_kernel",
>>> &panic_kernel, sizeof(panic_kernel));
>>> }
>>> +
>>> +int arch_do_exclude_segment(struct kexec_segment *seg_ptr, struct kexec_info *info)
>>> +{
>>> + if (info->elfcorehdr == (unsigned long) seg_ptr->mem)
>>> + return 1;
>>> +
>>> + return 0;
>>> +}
>>> diff --git a/kexec/arch/ia64/kexec-ia64.c b/kexec/arch/ia64/kexec-ia64.c
>>> index 418d997..8d9c1f3 100644
>>> --- a/kexec/arch/ia64/kexec-ia64.c
>>> +++ b/kexec/arch/ia64/kexec-ia64.c
>>> @@ -245,3 +245,7 @@ void arch_update_purgatory(struct kexec_info *UNUSED(info))
>>> {
>>> }
>>> +int arch_do_exclude_segment(struct kexec_segment *UNUSED(seg_ptr), struct kexec_info *UNUSED(info))
>>> +{
>>> + return 0;
>>> +}
>>> diff --git a/kexec/arch/loongarch/kexec-loongarch.c b/kexec/arch/loongarch/kexec-loongarch.c
>>> index ac75030..ee7b9f1 100644
>>> --- a/kexec/arch/loongarch/kexec-loongarch.c
>>> +++ b/kexec/arch/loongarch/kexec-loongarch.c
>>> @@ -381,3 +381,8 @@ unsigned long add_buffer(struct kexec_info *info, const void *buf,
>>> return add_buffer_phys_virt(info, buf, bufsz, memsz, buf_align,
>>> buf_min, buf_max, buf_end, 1);
>>> }
>>> +
>>> +int arch_do_exclude_segment(struct kexec_segment *UNUSED(seg_ptr), struct kexec_info *UNUSED(info))
>>> +{
>>> + return 0;
>>> +}
>>> diff --git a/kexec/arch/m68k/kexec-m68k.c b/kexec/arch/m68k/kexec-m68k.c
>>> index cb54927..0c7dbaf 100644
>>> --- a/kexec/arch/m68k/kexec-m68k.c
>>> +++ b/kexec/arch/m68k/kexec-m68k.c
>>> @@ -108,3 +108,8 @@ void add_segment(struct kexec_info *info, const void *buf, size_t bufsz,
>>> {
>>> add_segment_phys_virt(info, buf, bufsz, base, memsz, 1);
>>> }
>>> +
>>> +int arch_do_exclude_segment(struct kexec_segment *UNUSED(seg_ptr), struct kexec_info *UNUSED(info))
>>> +{
>>> + return 0;
>>> +}
>>> diff --git a/kexec/arch/mips/kexec-mips.c b/kexec/arch/mips/kexec-mips.c
>>> index d8cbea8..94224ee 100644
>>> --- a/kexec/arch/mips/kexec-mips.c
>>> +++ b/kexec/arch/mips/kexec-mips.c
>>> @@ -189,3 +189,7 @@ unsigned long add_buffer(struct kexec_info *info, const void *buf,
>>> buf_min, buf_max, buf_end, 1);
>>> }
>>> +int arch_do_exclude_segment(const void *UNUSED(seg_ptr), struct kexec_info *UNUSED(info))
>>> +{
>>> + return 0;
>>> +}
>>> diff --git a/kexec/arch/ppc/kexec-ppc.c b/kexec/arch/ppc/kexec-ppc.c
>>> index 03bec36..c8af870 100644
>>> --- a/kexec/arch/ppc/kexec-ppc.c
>>> +++ b/kexec/arch/ppc/kexec-ppc.c
>>> @@ -966,3 +966,7 @@ void arch_update_purgatory(struct kexec_info *UNUSED(info))
>>> {
>>> }
>>> +int arch_do_exclude_segment(struct kexec_segment *UNUSED(seg_ptr), struct kexec_info *UNUSED(info))
>>> +{
>>> + return 0;
>>> +}
>>> diff --git a/kexec/arch/ppc64/kexec-ppc64.c b/kexec/arch/ppc64/kexec-ppc64.c
>>> index bd5274c..fb27b6b 100644
>>> --- a/kexec/arch/ppc64/kexec-ppc64.c
>>> +++ b/kexec/arch/ppc64/kexec-ppc64.c
>>> @@ -967,3 +967,8 @@ int arch_compat_trampoline(struct kexec_info *UNUSED(info))
>>> void arch_update_purgatory(struct kexec_info *UNUSED(info))
>>> {
>>> }
>>> +
>>> +int arch_do_exclude_segment(struct kexec_segment *UNUSED(seg_ptr), struct kexec_info *UNUSED(info))
>>> +{
>>> + return 0;
>>> +}
>>> diff --git a/kexec/arch/s390/kexec-s390.c b/kexec/arch/s390/kexec-s390.c
>>> index 33ba6b9..0561ee7 100644
>>> --- a/kexec/arch/s390/kexec-s390.c
>>> +++ b/kexec/arch/s390/kexec-s390.c
>>> @@ -267,3 +267,8 @@ int get_crash_kernel_load_range(uint64_t *start, uint64_t *end)
>>> {
>>> return parse_iomem_single("Crash kernel\n", start, end);
>>> }
>>> +
>>> +int arch_do_exclude_segment(struct kexec_segment *UNUSED(seg_ptr), struct kexec_info *UNUSED(info))
>>> +{
>>> + return 0;
>>> +}
>>> diff --git a/kexec/arch/sh/kexec-sh.c b/kexec/arch/sh/kexec-sh.c
>>> index ce341c8..f84c40c 100644
>>> --- a/kexec/arch/sh/kexec-sh.c
>>> +++ b/kexec/arch/sh/kexec-sh.c
>>> @@ -257,3 +257,8 @@ unsigned long add_buffer(struct kexec_info *info, const void *buf,
>>> return add_buffer_phys_virt(info, buf, bufsz, memsz, buf_align,
>>> buf_min, buf_max, buf_end, 1);
>>> }
>>> +
>>> +int arch_do_exclude_segment(struct kexec_segment *UNUSED(seg_ptr), struct kexec_info *UNUSED(info))
>>> +{
>>> + return 0;
>>> +}
>>> diff --git a/kexec/arch/x86_64/kexec-x86_64.c b/kexec/arch/x86_64/kexec-x86_64.c
>>> index ffd84f0..42af90a 100644
>>> --- a/kexec/arch/x86_64/kexec-x86_64.c
>>> +++ b/kexec/arch/x86_64/kexec-x86_64.c
>>> @@ -188,3 +188,8 @@ void arch_update_purgatory(struct kexec_info *info)
>>> elf_rel_set_symbol(&info->rhdr, "panic_kernel",
>>> &panic_kernel, sizeof(panic_kernel));
>>> }
>>> +
>>> +int arch_do_exclude_segment(struct kexec_segment *UNUSED(seg_ptr), struct kexec_info *UNUSED(info))
>>> +{
>>> + return 0;
>>> +}
>>> diff --git a/kexec/kexec-syscall.h b/kexec/kexec-syscall.h
>>> index 73e5254..4675c46 100644
>>> --- a/kexec/kexec-syscall.h
>>> +++ b/kexec/kexec-syscall.h
>>> @@ -112,7 +112,7 @@ static inline long kexec_file_load(int kernel_fd, int initrd_fd,
>>> #define KEXEC_ON_CRASH 0x00000001
>>> #define KEXEC_PRESERVE_CONTEXT 0x00000002
>>> -#define KEXEC_UPDATE_ELFCOREHDR 0x00000004
>>> +#define KEXEC_CRASH_HOTPLUG_SUPPORT 0x00000008
>>> #define KEXEC_ARCH_MASK 0xffff0000
>>> /* Flags for kexec file based system call */
>>> diff --git a/kexec/kexec.c b/kexec/kexec.c
>>> index 222f79e..034cea6 100644
>>> --- a/kexec/kexec.c
>>> +++ b/kexec/kexec.c
>>> @@ -701,10 +701,13 @@ static void update_purgatory(struct kexec_info *info)
>>> continue;
>>> }
>>> - /* Don't include elfcorehdr in the checksum, if hotplug
>>> - * support enabled.
>>> + /*
>>> + * Let architecture decide which segments to exclude from checksum
>>> + * if hotplug support is enabled.
>>> */
>>> - if (do_hotplug && (info->segment[i].mem == (void *)info->elfcorehdr)) {
>>> + if (do_hotplug && arch_do_exclude_segment(&info->segment[i], info)) {
>>> + dbgprintf("Skipping segment mem: 0x%lx from SHA calculation\n",
>>> + (unsigned long)info->segment[i].mem);
>>> continue;
>>> }
>>> @@ -1651,7 +1654,6 @@ int main(int argc, char *argv[])
>>> die("--load-live-update can only be used with xen\n");
>>> }
>>> - /* NOTE: Xen KEXEC_LIVE_UPDATE and KEXEC_UPDATE_ELFCOREHDR collide */
>>> if (do_hotplug) {
>>> const char *ces = "/sys/kernel/crash_elfcorehdr_size";
>>> char *buf, *endptr = NULL;
>>> @@ -1665,8 +1667,8 @@ int main(int argc, char *argv[])
>>> if (!elfcorehdrsz || (endptr && *endptr != '\0'))
>>> die("Path %s does not exist, the kernel needs CONFIG_CRASH_HOTPLUG\n", ces);
>>> dbgprintf("ELFCOREHDR_SIZE %lu\n", elfcorehdrsz);
>>> - /* Indicate to the kernel it is ok to modify the elfcorehdr */
>>> - kexec_flags |= KEXEC_UPDATE_ELFCOREHDR;
>>> + /* Indicate to the kernel it is ok to modify the relevant kexec segments */
>>> + kexec_flags |= KEXEC_CRASH_HOTPLUG_SUPPORT;
>>> }
>>> fileind = optind;
>>> diff --git a/kexec/kexec.h b/kexec/kexec.h
>>> index 1004aff..2d758c9 100644
>>> --- a/kexec/kexec.h
>>> +++ b/kexec/kexec.h
>>> @@ -307,6 +307,8 @@ extern int do_hotplug;
>>> #define BOOTLOADER_VERSION PACKAGE_VERSION
>>> void arch_usage(void);
>>> +/* Return non-zero if segment needs to be excluded from SHA calculation, else 0. */
>>> +int arch_do_exclude_segment(struct kexec_segment *seg_ptr, struct kexec_info *info);
>>> int arch_process_options(int argc, char **argv);
>>> int arch_compat_trampoline(struct kexec_info *info);
>>> void arch_update_purgatory(struct kexec_info *info);
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