| Message ID | 20230427101838.12267-4-lizhijian@fujitsu.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | pmem memmap dump support | expand |
On Thu, Apr 27, 2023 at 06:18:34PM +0800, Li Zhijian wrote: > It does: > 1. Add pmem region into PT_LOADs of vmcore > 2. Mark pmem region's p_flags as PF_DEV I'm sorry, but I can not parse this changelog. Please take a look at the kernel documentation for how to write a good changelog message so that we can properly review the change you wish to have accepted. thanks, greg k-h
> diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c > index cdd92ab43cda..dc9d03083565 100644 > --- a/arch/x86/kernel/crash.c > +++ b/arch/x86/kernel/crash.c > @@ -178,6 +178,7 @@ static struct crash_mem *fill_up_crash_elf_data(void) > if (!nr_ranges) > return NULL; > > + walk_pmem_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback); So this will overwrite 'nr_ranges' produced by the previous walk_system_ram_res() call, sure it's correct? Regards, -jane
Jane, On 28/04/2023 04:41, Jane Chu wrote: >> diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c >> index cdd92ab43cda..dc9d03083565 100644 >> --- a/arch/x86/kernel/crash.c >> +++ b/arch/x86/kernel/crash.c >> @@ -178,6 +178,7 @@ static struct crash_mem *fill_up_crash_elf_data(void) >> if (!nr_ranges) >> return NULL; >> + walk_pmem_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback); > > So this will overwrite 'nr_ranges' produced by the previous walk_system_ram_res() call, sure it's correct? It depends on how the callback walk_system_ram_res() handle 'nr_ranges', so it's safe for this changes IMHO. 163 static int get_nr_ram_ranges_callback(struct resource *res, void *arg) 164 { 165 unsigned int *nr_ranges = arg; 166 167 (*nr_ranges)++; 168 return 0; 169 } 170 171 /* Gather all the required information to prepare elf headers for ram regions */ 172 static struct crash_mem *fill_up_crash_elf_data(void) 173 { 174 unsigned int nr_ranges = 0; 175 struct crash_mem *cmem; 176 177 walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback); 178 if (!nr_ranges) 179 return NULL; 180 181 walk_pmem_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback); At last, nr_ranges = #ram_res + #pmem_res. Thanks Zhijian > > Regards, > -jane
Greg, Sorry for these *BAD* changelog, This patch is most like a *HACKing* to resource.c currently. Please allow me to rewrite it once. Only the region described by PT_LOADs of /proc/vmcore are dumpable/readble by dumping applications. Previously, on x86/x86_64 only system ram resources will be injected into PT_LOADs. So in order to make the entire pmem resource is dumpable/readable, we need to add pmem region into the PT_LOADs of /proc/vmcore. Here we introduce a new API walk_pmem_res() to walk the pmem region first. Further, we will also mark pmem region with extra p_flags PF_DEV when it's adding into PT_LOADs. Then the dumping applications are able to know if the region is pmem or not according this flag and take special actions correspondingly. Thanks Zhijian On 27/04/2023 19:39, Greg Kroah-Hartman wrote: > On Thu, Apr 27, 2023 at 06:18:34PM +0800, Li Zhijian wrote: >> It does: >> 1. Add pmem region into PT_LOADs of vmcore >> 2. Mark pmem region's p_flags as PF_DEV > > I'm sorry, but I can not parse this changelog. > > Please take a look at the kernel documentation for how to write a good > changelog message so that we can properly review the change you wish to > have accepted. > > thanks, > > greg k-h
diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c index cdd92ab43cda..dc9d03083565 100644 --- a/arch/x86/kernel/crash.c +++ b/arch/x86/kernel/crash.c @@ -178,6 +178,7 @@ static struct crash_mem *fill_up_crash_elf_data(void) if (!nr_ranges) return NULL; + walk_pmem_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback); /* * Exclusion of crash region and/or crashk_low_res may cause * another range split. So add extra two slots here. @@ -243,6 +244,7 @@ static int prepare_elf_headers(struct kimage *image, void **addr, ret = walk_system_ram_res(0, -1, cmem, prepare_elf64_ram_headers_callback); if (ret) goto out; + walk_pmem_res(0, -1, cmem, prepare_elf64_ram_headers_callback); /* Exclude unwanted mem ranges */ ret = elf_header_exclude_ranges(cmem); diff --git a/include/linux/ioport.h b/include/linux/ioport.h index 25d768d48970..bde88a47cc1a 100644 --- a/include/linux/ioport.h +++ b/include/linux/ioport.h @@ -331,6 +331,9 @@ extern int walk_system_ram_res(u64 start, u64 end, void *arg, int (*func)(struct resource *, void *)); extern int +walk_pmem_res(u64 start, u64 end, void *arg, + int (*func)(struct resource *, void *)); +extern int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start, u64 end, void *arg, int (*func)(struct resource *, void *)); diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index f1a0e4e3fb5c..e79ceaee2926 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -29,6 +29,8 @@ #include <linux/vmalloc.h> #include "kexec_internal.h" +#define PF_DEV (1 << 4) + #ifdef CONFIG_KEXEC_SIG static bool sig_enforce = IS_ENABLED(CONFIG_KEXEC_SIG_FORCE); @@ -1221,6 +1223,12 @@ int crash_exclude_mem_range(struct crash_mem *mem, return 0; } +static bool is_pmem_range(u64 start, u64 size) +{ + return REGION_INTERSECTS == region_intersects(start, size, + IORESOURCE_MEM, IORES_DESC_PERSISTENT_MEMORY); +} + int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map, void **addr, unsigned long *sz) { @@ -1302,6 +1310,8 @@ int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map, phdr->p_type = PT_LOAD; phdr->p_flags = PF_R|PF_W|PF_X; + if (is_pmem_range(mstart, mend - mstart)) + phdr->p_flags |= PF_DEV; phdr->p_offset = mstart; phdr->p_paddr = mstart; diff --git a/kernel/resource.c b/kernel/resource.c index b1763b2fd7ef..f3f1ce6fc384 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -431,6 +431,17 @@ int walk_system_ram_res(u64 start, u64 end, void *arg, func); } +/* + * This function calls the @func callback against all memory ranges, which + * are ranges marked as IORESOURCE_MEM and IORES_DESC_PERSISTENT_MEMORY. + */ +int walk_pmem_res(u64 start, u64 end, void *arg, + int (*func)(struct resource *, void *)) +{ + return __walk_iomem_res_desc(start, end, IORESOURCE_MEM, + IORES_DESC_PERSISTENT_MEMORY, arg, func); +} + /* * This function calls the @func callback against all memory ranges, which * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY.
It does: 1. Add pmem region into PT_LOADs of vmcore 2. Mark pmem region's p_flags as PF_DEV CC: Thomas Gleixner <tglx@linutronix.de> CC: Ingo Molnar <mingo@redhat.com> CC: Borislav Petkov <bp@alien8.de> CC: Dave Hansen <dave.hansen@linux.intel.com> CC: "H. Peter Anvin" <hpa@zytor.com> CC: Eric Biederman <ebiederm@xmission.com> CC: Takashi Iwai <tiwai@suse.de> CC: Baoquan He <bhe@redhat.com> CC: Vlastimil Babka <vbabka@suse.cz> CC: Sean Christopherson <seanjc@google.com> CC: Jonathan Cameron <Jonathan.Cameron@huawei.com> CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> CC: Andy Shevchenko <andriy.shevchenko@linux.intel.com> CC: Dan Williams <dan.j.williams@intel.com> CC: "Rafael J. Wysocki" <rafael@kernel.org> CC: Ira Weiny <ira.weiny@intel.com> CC: Raul E Rangel <rrangel@chromium.org> CC: Colin Foster <colin.foster@in-advantage.com> CC: Vishal Verma <vishal.l.verma@intel.com> CC: x86@kernel.org Signed-off-by: Li Zhijian <lizhijian@fujitsu.com> --- arch/x86/kernel/crash.c | 2 ++ include/linux/ioport.h | 3 +++ kernel/kexec_file.c | 10 ++++++++++ kernel/resource.c | 11 +++++++++++ 4 files changed, 26 insertions(+)