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From: Masami Hiramatsu <mhiramat@kernel.org>
To: Borislav Petkov <bp@alien8.de>, Joerg Roedel <jroedel@suse.de>
Cc: Joerg Roedel <joro@8bytes.org>,
	x86@kernel.org, hpa@zytor.com, Andy Lutomirski <luto@kernel.org>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Thomas Hellstrom <thellstrom@vmware.com>,
	Jiri Slaby <jslaby@suse.cz>,
	Dan Williams <dan.j.williams@intel.com>,
	Tom Lendacky <thomas.lendacky@amd.com>,
	Juergen Gross <jgross@suse.com>,
	Kees Cook <keescook@chromium.org>,
	linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
	virtualization@lists.linux-foundation.org,
	Joerg Roedel <jroedel@suse.de>,
	Masami Hiramatsu <mhiramat@kernel.org>
Subject: Re: [PATCH 05/70] x86/insn: Make inat-tables.c suitable for pre-decompression code
Date: Fri, 27 Mar 2020 12:02:32 +0900
Message-ID: <20200327120232.c8e455ca100dc0d96e4ddc43@kernel.org> (raw)
In-Reply-To: <20200325153945.GD27261@zn.tnic>

Hi,

On Wed, 25 Mar 2020 16:39:45 +0100
Borislav Petkov <bp@alien8.de> wrote:

> + Masami.
> 
> On Thu, Mar 19, 2020 at 10:13:02AM +0100, Joerg Roedel wrote:
> > From: Joerg Roedel <jroedel@suse.de>
> > 
> > The inat-tables.c file has some arrays in it that contain pointers to
> > other arrays. These pointers need to be relocated when the kernel
> > image is moved to a different location.
> > 
> > The pre-decompression boot-code has no support for applying ELF
> > relocations, so initialize these arrays at runtime in the
> > pre-decompression code to make sure all pointers are correctly
> > initialized.

I need to check the whole series, but as far as I can understand from
this patch, this seems not allowing to store the address value in
static pointers. It may break more things, for example _kprobe_blacklist
records the NOKPROBE_SYMBOL() symbol addresses at the build time.

I have some comments here.
 
> > Signed-off-by: Joerg Roedel <jroedel@suse.de>
> > ---
> >  arch/x86/tools/gen-insn-attr-x86.awk       | 50 +++++++++++++++++++++-
> >  tools/arch/x86/tools/gen-insn-attr-x86.awk | 50 +++++++++++++++++++++-
> >  2 files changed, 98 insertions(+), 2 deletions(-)
> > 
> > diff --git a/arch/x86/tools/gen-insn-attr-x86.awk b/arch/x86/tools/gen-insn-attr-x86.awk
> > index a42015b305f4..af38469afd14 100644
> > --- a/arch/x86/tools/gen-insn-attr-x86.awk
> > +++ b/arch/x86/tools/gen-insn-attr-x86.awk
> > @@ -362,6 +362,9 @@ function convert_operands(count,opnd,       i,j,imm,mod)
> >  END {
> >  	if (awkchecked != "")
> >  		exit 1
> > +
> > +	print "#ifndef __BOOT_COMPRESSED\n"
> > +
> >  	# print escape opcode map's array
> >  	print "/* Escape opcode map array */"
> >  	print "const insn_attr_t * const inat_escape_tables[INAT_ESC_MAX + 1]" \
> > @@ -388,6 +391,51 @@ END {
> >  		for (j = 0; j < max_lprefix; j++)
> >  			if (atable[i,j])
> >  				print "	["i"]["j"] = "atable[i,j]","
> > -	print "};"
> > +	print "};\n"
> > +
> > +	print "#else /* !__BOOT_COMPRESSED */\n"

I think the definitions of inat_*_tables can be shared in both case.
If __BOOT_COMPRESSED is set, we can define inat_init_tables() as a
initialize function, and if not, it will be just a dummy "do {} while (0)".

BTW, where is the __BOOT_COMPRESSED defined?

> > +
> > +	print "/* Escape opcode map array */"
> > +	print "static const insn_attr_t *inat_escape_tables[INAT_ESC_MAX + 1]" \
> > +	      "[INAT_LSTPFX_MAX + 1];"
> > +	print ""
> > +
> > +	print "/* Group opcode map array */"
> > +	print "static const insn_attr_t *inat_group_tables[INAT_GRP_MAX + 1]"\
> > +	      "[INAT_LSTPFX_MAX + 1];"
> > +	print ""
> > +
> > +	print "/* AVX opcode map array */"
> > +	print "static const insn_attr_t *inat_avx_tables[X86_VEX_M_MAX + 1]"\
> > +	      "[INAT_LSTPFX_MAX + 1];"
> > +	print ""
> > +
> > +	print "static void inat_init_tables(void)"

This functions should be "inline".
And I can not see the call-site of inat_init_tables() in this patch.

If possible, please include call-site with definition (especially
new init function) so that I can check the init call timing too.

> > +	print "{"
> > +
> > +	# print escape opcode map's array
> > +	print "\t/* Print Escape opcode map array */"
> > +	for (i = 0; i < geid; i++)
> > +		for (j = 0; j < max_lprefix; j++)
> > +			if (etable[i,j])
> > +				print "\tinat_escape_tables["i"]["j"] = "etable[i,j]";"
> > +	print ""
> > +
> > +	# print group opcode map's array
> > +	print "\t/* Print Group opcode map array */"
> > +	for (i = 0; i < ggid; i++)
> > +		for (j = 0; j < max_lprefix; j++)
> > +			if (gtable[i,j])
> > +				print "\tinat_group_tables["i"]["j"] = "gtable[i,j]";"
> > +	print ""
> > +	# print AVX opcode map's array
> > +	print "\t/* Print AVX opcode map array */"
> > +	for (i = 0; i < gaid; i++)
> > +		for (j = 0; j < max_lprefix; j++)
> > +			if (atable[i,j])
> > +				print "\tinat_avx_tables["i"]["j"] = "atable[i,j]";"
> > +
> > +	print "}"
> > +	print "#endif"
> >  }

The code itself looks good to me.

Thank you,

-- 
Masami Hiramatsu <mhiramat@kernel.org>

  reply index

Thread overview: 109+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-19  9:12 [RFC PATCH 00/70 v2] x86: SEV-ES Guest Support Joerg Roedel
2020-03-19  9:12 ` [PATCH 01/70] KVM: SVM: Add GHCB definitions Joerg Roedel
2020-03-23 13:23   ` [PATCH] KVM: SVM: Use __packed shorthard Borislav Petkov
2020-03-24 12:43     ` Joerg Roedel
2020-03-19  9:12 ` [PATCH 02/70] KVM: SVM: Add GHCB Accessor functions Joerg Roedel
2020-03-19  9:13 ` [PATCH 03/70] x86/cpufeatures: Add SEV-ES CPU feature Joerg Roedel
2020-03-19  9:13 ` [PATCH 04/70] x86/traps: Move some definitions to <asm/trap_defs.h> Joerg Roedel
2020-03-19  9:13 ` [PATCH 05/70] x86/insn: Make inat-tables.c suitable for pre-decompression code Joerg Roedel
2020-03-25 15:39   ` Borislav Petkov
2020-03-27  3:02     ` Masami Hiramatsu [this message]
2020-03-19  9:13 ` [PATCH 06/70] x86/umip: Factor out instruction fetch Joerg Roedel
2020-03-26 17:21   ` Borislav Petkov
2020-03-19  9:13 ` [PATCH 07/70] x86/umip: Factor out instruction decoding Joerg Roedel
2020-03-26 17:24   ` Borislav Petkov
2020-03-19  9:13 ` [PATCH 08/70] x86/insn: Add insn_get_modrm_reg_off() Joerg Roedel
2020-03-27  3:57   ` Masami Hiramatsu
2020-03-19  9:13 ` [PATCH 09/70] x86/insn: Add insn_rep_prefix() helper Joerg Roedel
2020-03-27  3:56   ` Masami Hiramatsu
2020-03-19  9:13 ` [PATCH 10/70] x86/boot/compressed: Fix debug_puthex() parameter type Joerg Roedel
2020-03-19  9:13 ` [PATCH 11/70] x86/boot/compressed/64: Disable red-zone usage Joerg Roedel
2020-03-31 13:16   ` Borislav Petkov
2020-03-19  9:13 ` [PATCH 12/70] x86/boot/compressed/64: Add IDT Infrastructure Joerg Roedel
2020-03-19  9:13 ` [PATCH 13/70] x86/boot/compressed/64: Rename kaslr_64.c to ident_map_64.c Joerg Roedel
2020-03-19  9:13 ` [PATCH 14/70] x86/boot/compressed/64: Add page-fault handler Joerg Roedel
2020-03-19  9:13 ` [PATCH 15/70] x86/boot/compressed/64: Always switch to own page-table Joerg Roedel
2020-03-19  9:13 ` [PATCH 16/70] x86/boot/compressed/64: Don't pre-map memory in KASLR code Joerg Roedel
2020-03-19  9:13 ` [PATCH 17/70] x86/boot/compressed/64: Change add_identity_map() to take start and end Joerg Roedel
2020-03-19  9:13 ` [PATCH 18/70] x86/boot/compressed/64: Add stage1 #VC handler Joerg Roedel
2020-03-20 21:16   ` David Rientjes
2020-03-20 22:19     ` Joerg Roedel
2020-03-19  9:13 ` [PATCH 19/70] x86/boot/compressed/64: Call set_sev_encryption_mask earlier Joerg Roedel
2020-03-19  9:13 ` [PATCH 20/70] x86/boot/compressed/64: Check return value of kernel_ident_mapping_init() Joerg Roedel
2020-03-19  9:13 ` [PATCH 21/70] x86/boot/compressed/64: Add function to map a page unencrypted Joerg Roedel
2020-03-20 20:53   ` David Rientjes
2020-03-20 21:02     ` Dave Hansen
2020-03-20 22:12       ` Joerg Roedel
2020-03-20 22:26         ` Dave Hansen
2020-03-21 15:40           ` Joerg Roedel
2020-03-19  9:13 ` [PATCH 22/70] x86/boot/compressed/64: Setup GHCB Based VC Exception handler Joerg Roedel
2020-03-19  9:13 ` [PATCH 23/70] x86/sev-es: Add support for handling IOIO exceptions Joerg Roedel
2020-03-20 21:03   ` David Rientjes
2020-03-20 22:24     ` Joerg Roedel
2020-03-19  9:13 ` [PATCH 24/70] x86/fpu: Move xgetbv()/xsetbv() into separate header Joerg Roedel
2020-03-19  9:13 ` [PATCH 25/70] x86/sev-es: Add CPUID handling to #VC handler Joerg Roedel
2020-03-19  9:13 ` [PATCH 26/70] x86/idt: Move IDT to data segment Joerg Roedel
2020-03-19  9:13 ` [PATCH 27/70] x86/idt: Split idt_data setup out of set_intr_gate() Joerg Roedel
2020-03-19  9:13 ` [PATCH 28/70] x86/idt: Move two function from k/idt.c to i/a/desc.h Joerg Roedel
2020-03-19  9:13 ` [PATCH 29/70] x86/head/64: Install boot GDT Joerg Roedel
2020-03-19  9:13 ` [PATCH 30/70] x86/head/64: Reload GDT after switch to virtual addresses Joerg Roedel
2020-03-19  9:13 ` [PATCH 31/70] x86/head/64: Load segment registers earlier Joerg Roedel
2020-03-19  9:13 ` [PATCH 32/70] x86/head/64: Switch to initial stack earlier Joerg Roedel
2020-03-19  9:13 ` [PATCH 33/70] x86/head/64: Build k/head64.c with -fno-stack-protector Joerg Roedel
2020-03-19  9:13 ` [PATCH 34/70] x86/head/64: Load IDT earlier Joerg Roedel
2020-03-19  9:13 ` [PATCH 35/70] x86/head/64: Move early exception dispatch to C code Joerg Roedel
2020-03-19  9:13 ` [PATCH 36/70] x86/sev-es: Add SEV-ES Feature Detection Joerg Roedel
2020-03-19  9:13 ` [PATCH 37/70] x86/sev-es: Compile early handler code into kernel image Joerg Roedel
2020-03-19  9:13 ` [PATCH 38/70] x86/sev-es: Setup early #VC handler Joerg Roedel
2020-03-19  9:13 ` [PATCH 39/70] x86/sev-es: Setup GHCB based boot " Joerg Roedel
2020-03-19  9:13 ` [PATCH 40/70] x86/sev-es: Setup per-cpu GHCBs for the runtime handler Joerg Roedel
2020-03-19  9:13 ` [PATCH 41/70] x86/sev-es: Add Runtime #VC Exception Handler Joerg Roedel
2020-03-19 15:44   ` Andy Lutomirski
2020-03-19 16:24     ` Joerg Roedel
2020-03-19 18:43       ` Andy Lutomirski
2020-03-19 19:38         ` Joerg Roedel
2020-03-19  9:13 ` [PATCH 42/70] x86/sev-es: Support nested #VC exceptions Joerg Roedel
2020-03-19 15:46   ` Andy Lutomirski
2020-03-19 16:12     ` Joerg Roedel
2020-03-19  9:13 ` [PATCH 43/70] x86/sev-es: Wire up existing #VC exit-code handlers Joerg Roedel
2020-03-19  9:13 ` [PATCH 44/70] x86/sev-es: Handle instruction fetches from user-space Joerg Roedel
2020-03-19  9:13 ` [PATCH 45/70] x86/sev-es: Harden runtime #VC handler for exceptions " Joerg Roedel
2020-03-19  9:13 ` [PATCH 46/70] x86/sev-es: Filter exceptions not supported " Joerg Roedel
2020-03-19  9:13 ` [PATCH 47/70] x86/sev-es: Handle MMIO events Joerg Roedel
2020-03-19  9:13 ` [PATCH 48/70] x86/sev-es: Handle MMIO String Instructions Joerg Roedel
2020-03-19  9:13 ` [PATCH 49/70] x86/sev-es: Handle MSR events Joerg Roedel
2020-03-19  9:13 ` [PATCH 50/70] x86/sev-es: Handle DR7 read/write events Joerg Roedel
2020-03-19  9:13 ` [PATCH 51/70] x86/sev-es: Handle WBINVD Events Joerg Roedel
2020-03-19  9:13 ` [PATCH 52/70] x86/sev-es: Handle RDTSC Events Joerg Roedel
2020-03-19  9:13 ` [PATCH 53/70] x86/sev-es: Handle RDPMC Events Joerg Roedel
2020-03-19  9:13 ` [PATCH 54/70] x86/sev-es: Handle INVD Events Joerg Roedel
2020-03-19  9:13 ` [PATCH 55/70] x86/sev-es: Handle RDTSCP Events Joerg Roedel
2020-03-19  9:13 ` [PATCH 56/70] x86/sev-es: Handle MONITOR/MONITORX Events Joerg Roedel
2020-03-19  9:13 ` [PATCH 57/70] x86/sev-es: Handle MWAIT/MWAITX Events Joerg Roedel
2020-03-19  9:13 ` [PATCH 58/70] x86/sev-es: Handle VMMCALL Events Joerg Roedel
2020-03-19  9:13 ` [PATCH 59/70] x86/sev-es: Handle #AC Events Joerg Roedel
2020-03-19  9:13 ` [PATCH 60/70] x86/sev-es: Handle #DB Events Joerg Roedel
2020-03-19  9:13 ` [PATCH 61/70] x86/paravirt: Allow hypervisor specific VMMCALL handling under SEV-ES Joerg Roedel
2020-03-19  9:13 ` [PATCH 62/70] x86/kvm: Add KVM " Joerg Roedel
2020-03-20 21:23   ` David Rientjes
2020-03-20 22:21     ` Joerg Roedel
2020-03-19  9:14 ` [PATCH 63/70] x86/vmware: Add VMware specific handling for VMMCALL " Joerg Roedel
2020-03-19 10:18   ` Thomas Hellstrom
2020-03-19  9:14 ` [PATCH 64/70] x86/realmode: Add SEV-ES specific trampoline entry point Joerg Roedel
2020-03-19  9:14 ` [PATCH 65/70] x86/realmode: Setup AP jump table Joerg Roedel
2020-03-19  9:14 ` [PATCH 66/70] x86/head/64: Don't call verify_cpu() on starting APs Joerg Roedel
2020-03-19  9:14 ` [PATCH 67/70] x86/head/64: Rename start_cpu0 Joerg Roedel
2020-03-19  9:14 ` [PATCH 68/70] x86/sev-es: Support CPU offline/online Joerg Roedel
2020-03-19  9:14 ` [PATCH 69/70] x86/cpufeature: Add SEV_ES_GUEST CPU Feature Joerg Roedel
2020-03-19  9:14 ` [PATCH 70/70] x86/sev-es: Add NMI state tracking Joerg Roedel
2020-03-19 15:35   ` Andy Lutomirski
2020-03-19 16:07     ` Joerg Roedel
2020-03-19 18:40       ` Andy Lutomirski
2020-03-19 19:26         ` Joerg Roedel
2020-03-19 21:27           ` Andy Lutomirski
2020-03-20 19:48             ` Joerg Roedel
2020-03-20 13:17     ` [RFC PATCH v2.1] x86/sev-es: Handle NMI State Joerg Roedel
2020-03-20 14:42       ` Dave Hansen
2020-03-20 19:42         ` Joerg Roedel
2020-03-19 16:53   ` [PATCH 70/70] x86/sev-es: Add NMI state tracking Mika Penttilä
2020-03-19 19:41     ` Joerg Roedel

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