Messages in this thread | | | Date | Wed, 20 Mar 2019 08:25:24 +0800 | From | Baoquan He <> | Subject | Re: [PATCHv2] x86/boot/KASLR: skip the specified crashkernel reserved region |
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Please change subject as:
"x86/boot/KASLR: skip the specified crashkernel region"
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()?
Except of these, patch looks good to me. It's a nice catch, and only need a simple fix based on the current code.
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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