[Linux-stable-mirror] [PATCHv3 1/5] x86/boot/compressed/64: Detect and handle 5-level paging at boot-time
This patch prepare decompression code to boot-time switching between 4- and 5-level paging.
Signed-off-by: Kirill A. Shutemov kirill.shutemov@linux.intel.com Cc: stable@vger.kernel.org [4.14+] --- arch/x86/boot/compressed/Makefile | 1 + arch/x86/boot/compressed/head_64.S | 16 ++++++++++++---- arch/x86/boot/compressed/pgtable_64.c | 18 ++++++++++++++++++ 3 files changed, 31 insertions(+), 4 deletions(-) create mode 100644 arch/x86/boot/compressed/pgtable_64.c
diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index 1e9c322e973a..f25e1530e064 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -80,6 +80,7 @@ vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/kaslr.o ifdef CONFIG_X86_64 vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/pagetable.o vmlinux-objs-y += $(obj)/mem_encrypt.o + vmlinux-objs-y += $(obj)/pgtable_64.o endif
$(obj)/eboot.o: KBUILD_CFLAGS += -fshort-wchar -mno-red-zone diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index 20919b4f3133..fc313e29fe2c 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -305,10 +305,18 @@ ENTRY(startup_64) leaq boot_stack_end(%rbx), %rsp
#ifdef CONFIG_X86_5LEVEL - /* Check if 5-level paging has already enabled */ - movq %cr4, %rax - testl $X86_CR4_LA57, %eax - jnz lvl5 + /* + * Check if we need to enable 5-level paging. + * RSI holds real mode data and need to be preserved across + * a function call. + */ + pushq %rsi + call l5_paging_required + popq %rsi + + /* If l5_paging_required() returned zero, we're done here. */ + cmpq $0, %rax + je lvl5
/* * At this point we are in long mode with 4-level paging enabled, diff --git a/arch/x86/boot/compressed/pgtable_64.c b/arch/x86/boot/compressed/pgtable_64.c new file mode 100644 index 000000000000..eed3a2c3b577 --- /dev/null +++ b/arch/x86/boot/compressed/pgtable_64.c @@ -0,0 +1,18 @@ +#include <asm/processor.h> + +int l5_paging_required(void) +{ + /* Check i leaf 7 is supported. */ + if (native_cpuid_eax(0) < 7) + return 0; + + /* Check if la57 is supported. */ + if (!(native_cpuid_ecx(7) & (1 << (X86_FEATURE_LA57 & 31)))) + return 0; + + /* Check if 5-level paging has already been enabled. */ + if (native_read_cr4() & X86_CR4_LA57) + return 0; + + return 1; +}
On Mon, 4 Dec 2017, Kirill A. Shutemov wrote:
This patch prepare decompression code to boot-time switching between 4- and 5-level paging.
This is the very wrong reason for tagging this commit stable.
Signed-off-by: Kirill A. Shutemov kirill.shutemov@linux.intel.com Cc: stable@vger.kernel.org [4.14+]
Adding cc stable requires a Fixes tag as well.
+int l5_paging_required(void) +{
- /* Check i leaf 7 is supported. */
So you introduce the typo here and then you fix it in the next patch which is the actual bug fix as an completely unrelated hunk.
-- a/arch/x86/boot/compressed/pgtable_64.c +++ b/arch/x86/boot/compressed/pgtable_64.c @@ -2,7 +2,7 @@
int l5_paging_required(void) { - /* Check i leaf 7 is supported. */ + /* Check if leaf 7 is supported. */
That's just careless and sloppy.
I fixed it up once more along with the lousy changelogs because this crap, which you not even thought about addressing it when shoving your 5-level support into 4.14 needs to be fixed.
I'm really tired of your sloppiness. You waste everyones time just by ignoring feedback and continuing to do what you think is enough. Works for me is _NOT_ enough for kernel development.
I'm not even looking at the rest of the series unless someone else has the stomach to do so and sends a Reviewed-by.
Alternatively you can sit down and look at the changelogs and the code and figure out whether it matches what I told you over and over. Once you think it does, then please feel free to resend it, but be sure that I'm going to apply the most restrictive crap filter on anything which comes from you from now on.
Thanks,
tglx
On Mon, Dec 04, 2017 at 09:29:45PM +0100, Thomas Gleixner wrote:
On Mon, 4 Dec 2017, Kirill A. Shutemov wrote:
This patch prepare decompression code to boot-time switching between 4- and 5-level paging.
This is the very wrong reason for tagging this commit stable.
Signed-off-by: Kirill A. Shutemov kirill.shutemov@linux.intel.com Cc: stable@vger.kernel.org [4.14+]
Adding cc stable requires a Fixes tag as well.
+int l5_paging_required(void) +{
- /* Check i leaf 7 is supported. */
So you introduce the typo here and then you fix it in the next patch which is the actual bug fix as an completely unrelated hunk.
-- a/arch/x86/boot/compressed/pgtable_64.c +++ b/arch/x86/boot/compressed/pgtable_64.c @@ -2,7 +2,7 @@ int l5_paging_required(void) {
/* Check i leaf 7 is supported. */
/* Check if leaf 7 is supported. */That's just careless and sloppy.
I fixed it up once more along with the lousy changelogs because this crap, which you not even thought about addressing it when shoving your 5-level support into 4.14 needs to be fixed.
I'm really tired of your sloppiness. You waste everyones time just by ignoring feedback and continuing to do what you think is enough. Works for me is _NOT_ enough for kernel development.
Sorry. I screwed it up.
I'll do my best to not waste your time again.
I'm not even looking at the rest of the series unless someone else has the stomach to do so and sends a Reviewed-by.
Alternatively you can sit down and look at the changelogs and the code and figure out whether it matches what I told you over and over. Once you think it does, then please feel free to resend it, but be sure that I'm going to apply the most restrictive crap filter on anything which comes from you from now on.
Fair enough. I'll recheck everything in the morning and send them again.
Thanks, and sorry again for wasting your time.
linux-stable-mirror@lists.linaro.org
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Kirill A. Shutemov -
Kirill A. Shutemov -
Thomas Gleixner