diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-06-28 10:59:38 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-06-28 10:59:38 -0700 |
commit | 77b1a7f7a05c673c187894b4ae898a8c0cdc776c (patch) | |
tree | e5f86addd81715393efcc7e3ba07cd68de31adf4 /kernel/kexec_core.c | |
parent | 6e17c6de3ddf3073741d9c91a796ee696914d8a0 (diff) | |
parent | 4afc9a402aa3890885747b396c1adcd45f127665 (diff) |
Merge tag 'mm-nonmm-stable-2023-06-24-19-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-mm updates from Andrew Morton:
- Arnd Bergmann has fixed a bunch of -Wmissing-prototypes in top-level
directories
- Douglas Anderson has added a new "buddy" mode to the hardlockup
detector. It permits the detector to work on architectures which
cannot provide the required interrupts, by having CPUs periodically
perform checks on other CPUs
- Zhen Lei has enhanced kexec's ability to support two crash regions
- Petr Mladek has done a lot of cleanup on the hard lockup detector's
Kconfig entries
- And the usual bunch of singleton patches in various places
* tag 'mm-nonmm-stable-2023-06-24-19-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (72 commits)
kernel/time/posix-stubs.c: remove duplicated include
ocfs2: remove redundant assignment to variable bit_off
watchdog/hardlockup: fix typo in config HARDLOCKUP_DETECTOR_PREFER_BUDDY
powerpc: move arch_trigger_cpumask_backtrace from nmi.h to irq.h
devres: show which resource was invalid in __devm_ioremap_resource()
watchdog/hardlockup: define HARDLOCKUP_DETECTOR_ARCH
watchdog/sparc64: define HARDLOCKUP_DETECTOR_SPARC64
watchdog/hardlockup: make HAVE_NMI_WATCHDOG sparc64-specific
watchdog/hardlockup: declare arch_touch_nmi_watchdog() only in linux/nmi.h
watchdog/hardlockup: make the config checks more straightforward
watchdog/hardlockup: sort hardlockup detector related config values a logical way
watchdog/hardlockup: move SMP barriers from common code to buddy code
watchdog/buddy: simplify the dependency for HARDLOCKUP_DETECTOR_PREFER_BUDDY
watchdog/buddy: don't copy the cpumask in watchdog_next_cpu()
watchdog/buddy: cleanup how watchdog_buddy_check_hardlockup() is called
watchdog/hardlockup: remove softlockup comment in touch_nmi_watchdog()
watchdog/hardlockup: in watchdog_hardlockup_check() use cpumask_copy()
watchdog/hardlockup: don't use raw_cpu_ptr() in watchdog_hardlockup_kick()
watchdog/hardlockup: HAVE_NMI_WATCHDOG must implement watchdog_hardlockup_probe()
watchdog/hardlockup: keep kernel.nmi_watchdog sysctl as 0444 if probe fails
...
Diffstat (limited to 'kernel/kexec_core.c')
-rw-r--r-- | kernel/kexec_core.c | 93 |
1 files changed, 65 insertions, 28 deletions
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c index 3d578c6fefee..e2f2574d8b74 100644 --- a/kernel/kexec_core.c +++ b/kernel/kexec_core.c @@ -1091,6 +1091,11 @@ __bpf_kfunc void crash_kexec(struct pt_regs *regs) } } +static inline resource_size_t crash_resource_size(const struct resource *res) +{ + return !res->end ? 0 : resource_size(res); +} + ssize_t crash_get_memory_size(void) { ssize_t size = 0; @@ -1098,19 +1103,45 @@ ssize_t crash_get_memory_size(void) if (!kexec_trylock()) return -EBUSY; - if (crashk_res.end != crashk_res.start) - size = resource_size(&crashk_res); + size += crash_resource_size(&crashk_res); + size += crash_resource_size(&crashk_low_res); kexec_unlock(); return size; } +static int __crash_shrink_memory(struct resource *old_res, + unsigned long new_size) +{ + struct resource *ram_res; + + ram_res = kzalloc(sizeof(*ram_res), GFP_KERNEL); + if (!ram_res) + return -ENOMEM; + + ram_res->start = old_res->start + new_size; + ram_res->end = old_res->end; + ram_res->flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM; + ram_res->name = "System RAM"; + + if (!new_size) { + release_resource(old_res); + old_res->start = 0; + old_res->end = 0; + } else { + crashk_res.end = ram_res->start - 1; + } + + crash_free_reserved_phys_range(ram_res->start, ram_res->end); + insert_resource(&iomem_resource, ram_res); + + return 0; +} + int crash_shrink_memory(unsigned long new_size) { int ret = 0; - unsigned long start, end; - unsigned long old_size; - struct resource *ram_res; + unsigned long old_size, low_size; if (!kexec_trylock()) return -EBUSY; @@ -1119,36 +1150,42 @@ int crash_shrink_memory(unsigned long new_size) ret = -ENOENT; goto unlock; } - start = crashk_res.start; - end = crashk_res.end; - old_size = (end == 0) ? 0 : end - start + 1; + + low_size = crash_resource_size(&crashk_low_res); + old_size = crash_resource_size(&crashk_res) + low_size; + new_size = roundup(new_size, KEXEC_CRASH_MEM_ALIGN); if (new_size >= old_size) { ret = (new_size == old_size) ? 0 : -EINVAL; goto unlock; } - ram_res = kzalloc(sizeof(*ram_res), GFP_KERNEL); - if (!ram_res) { - ret = -ENOMEM; - goto unlock; - } - - start = roundup(start, KEXEC_CRASH_MEM_ALIGN); - end = roundup(start + new_size, KEXEC_CRASH_MEM_ALIGN); - - crash_free_reserved_phys_range(end, crashk_res.end); - - if ((start == end) && (crashk_res.parent != NULL)) - release_resource(&crashk_res); - - ram_res->start = end; - ram_res->end = crashk_res.end; - ram_res->flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM; - ram_res->name = "System RAM"; + /* + * (low_size > new_size) implies that low_size is greater than zero. + * This also means that if low_size is zero, the else branch is taken. + * + * If low_size is greater than 0, (low_size > new_size) indicates that + * crashk_low_res also needs to be shrunken. Otherwise, only crashk_res + * needs to be shrunken. + */ + if (low_size > new_size) { + ret = __crash_shrink_memory(&crashk_res, 0); + if (ret) + goto unlock; - crashk_res.end = end - 1; + ret = __crash_shrink_memory(&crashk_low_res, new_size); + } else { + ret = __crash_shrink_memory(&crashk_res, new_size - low_size); + } - insert_resource(&iomem_resource, ram_res); + /* Swap crashk_res and crashk_low_res if needed */ + if (!crashk_res.end && crashk_low_res.end) { + crashk_res.start = crashk_low_res.start; + crashk_res.end = crashk_low_res.end; + release_resource(&crashk_low_res); + crashk_low_res.start = 0; + crashk_low_res.end = 0; + insert_resource(&iomem_resource, &crashk_res); + } unlock: kexec_unlock(); |