Messages in this thread Patch in this message | | | From | Pingfan Liu <> | Date | Fri, 22 Mar 2019 15:43:35 +0800 | Subject | Re: [PATCHv2] x86/boot/KASLR: skip the specified crashkernel reserved region |
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On Wed, Mar 20, 2019 at 8:25 AM Baoquan He <bhe@redhat.com> wrote: > > Please change subject as: > > "x86/boot/KASLR: skip the specified crashkernel region" > OK.
> Don't see why reserved is needed here. > > On 03/13/19 at 12:19pm, Pingfan Liu wrote: > > crashkernel=x@y option may fail to reserve the required memory region if > > KASLR puts kernel into the region. To avoid this uncertainty, making KASLR > > skip the required region. > > > > Signed-off-by: Pingfan Liu <kernelfans@gmail.com> > > Cc: Thomas Gleixner <tglx@linutronix.de> > > Cc: Ingo Molnar <mingo@redhat.com> > > Cc: Borislav Petkov <bp@alien8.de> > > Cc: "H. Peter Anvin" <hpa@zytor.com> > > Cc: Baoquan He <bhe@redhat.com> > > Cc: Will Deacon <will.deacon@arm.com> > > Cc: Nicolas Pitre <nico@linaro.org> > > Cc: Pingfan Liu <kernelfans@gmail.com> > > Cc: Chao Fan <fanc.fnst@cn.fujitsu.com> > > Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> > > Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> > > Cc: linux-kernel@vger.kernel.org > > --- > > v1 -> v2: fix some trival format > > > > arch/x86/boot/compressed/kaslr.c | 26 ++++++++++++++++++++++++-- > > 1 file changed, 24 insertions(+), 2 deletions(-) > > > > diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c > > index 9ed9709..e185318 100644 > > --- a/arch/x86/boot/compressed/kaslr.c > > +++ b/arch/x86/boot/compressed/kaslr.c > > @@ -109,6 +109,7 @@ enum mem_avoid_index { > > MEM_AVOID_BOOTPARAMS, > > MEM_AVOID_MEMMAP_BEGIN, > > MEM_AVOID_MEMMAP_END = MEM_AVOID_MEMMAP_BEGIN + MAX_MEMMAP_REGIONS - 1, > > + MEM_AVOID_CRASHKERNEL, > > MEM_AVOID_MAX, > > }; > > > > @@ -240,6 +241,25 @@ static void parse_gb_huge_pages(char *param, char *val) > > } > > } > > > > +/* parse crashkernel=x@y option */ > > +static void mem_avoid_crashkernel_simple(char *option) > > Chao ever mentioned this, I want to ask again, why does it has to be > xxx_simple()? > Seems that I had replied Chao's question in another email. The naming follows the function parse_crashkernel_simple(), as the notes above the definition /* * That function parses "simple" (old) crashkernel command lines like * * crashkernel=size[@offset] * * It returns 0 on success and -EINVAL on failure. */ static int __init parse_crashkernel_simple(char *cmdline,
Do you have alternative suggestion?
> Except of these, patch looks good to me. It's a nice catch, and only > need a simple fix based on the current code. > Thank you for the kindly review.
Regards, Pingfan
> Thanks > Baoquan > > > +{ > > + unsigned long long crash_size, crash_base; > > + char *cur = option; > > + > > + crash_size = memparse(option, &cur); > > + if (option == cur) > > + return; > > + > > + if (*cur == '@') { > > + option = cur + 1; > > + crash_base = memparse(option, &cur); > > + if (option == cur) > > + return; > > + mem_avoid[MEM_AVOID_CRASHKERNEL].start = crash_base; > > + mem_avoid[MEM_AVOID_CRASHKERNEL].size = crash_size; > > + } > > +} > > > > static void handle_mem_options(void) > > { > > @@ -250,7 +270,7 @@ static void handle_mem_options(void) > > u64 mem_size; > > > > if (!strstr(args, "memmap=") && !strstr(args, "mem=") && > > - !strstr(args, "hugepages")) > > + !strstr(args, "hugepages") && !strstr(args, "crashkernel=")) > > return; > > > > tmp_cmdline = malloc(len + 1); > > @@ -286,6 +306,8 @@ static void handle_mem_options(void) > > goto out; > > > > mem_limit = mem_size; > > + } else if (strstr(param, "crashkernel")) { > > + mem_avoid_crashkernel_simple(val); > > } > > } > > > > @@ -414,7 +436,7 @@ static void mem_avoid_init(unsigned long input, unsigned long input_size, > > > > /* We don't need to set a mapping for setup_data. */ > > > > - /* Mark the memmap regions we need to avoid */ > > + /* Mark the regions we need to avoid */ > > handle_mem_options(); > > > > #ifdef CONFIG_X86_VERBOSE_BOOTUP > > -- > > 2.7.4 > >
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