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x86/boot: Hide local labels in verify_cpu()

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... from the final ELF image's symbol table as they're not
really needed there.

Before:

$ readelf -a vmlinux | grep verify_cpu
    43: ffffffff810001a9     0 NOTYPE  LOCAL  DEFAULT    1 verify_cpu
    45: ffffffff8100028f     0 NOTYPE  LOCAL  DEFAULT    1 verify_cpu_no_longmode
    46: ffffffff810001de     0 NOTYPE  LOCAL  DEFAULT    1 verify_cpu_noamd
    47: ffffffff8100022b     0 NOTYPE  LOCAL  DEFAULT    1 verify_cpu_check
    48: ffffffff8100021c     0 NOTYPE  LOCAL  DEFAULT    1 verify_cpu_clear_xd
    49: ffffffff81000263     0 NOTYPE  LOCAL  DEFAULT    1 verify_cpu_sse_test
    50: ffffffff81000296     0 NOTYPE  LOCAL  DEFAULT    1 verify_cpu_sse_ok

After:

$ readelf -a vmlinux | grep verify_cpu
    43: ffffffff810001a9     0 NOTYPE  LOCAL  DEFAULT    1 verify_cpu

No functionality change.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1451860733-21163-1-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Borislav Petkov 2016-01-03 23:38:53 +01:00 committed by Ingo Molnar
parent 394db20ca2
commit aa0421410f
1 changed files with 25 additions and 25 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

50
arch/x86/kernel/verify_cpu.S
View File

@ -48,31 +48,31 @@ verify_cpu:
pushfl
popl %eax
cmpl %eax,%ebx
jz verify_cpu_no_longmode # cpu has no cpuid
jz .Lverify_cpu_no_longmode # cpu has no cpuid
#endif
movl $0x0,%eax # See if cpuid 1 is implemented
cpuid
cmpl $0x1,%eax
jb verify_cpu_no_longmode # no cpuid 1
jb .Lverify_cpu_no_longmode # no cpuid 1
xor %di,%di
cmpl $0x68747541,%ebx # AuthenticAMD
jnz verify_cpu_noamd
jnz .Lverify_cpu_noamd
cmpl $0x69746e65,%edx
jnz verify_cpu_noamd
jnz .Lverify_cpu_noamd
cmpl $0x444d4163,%ecx
jnz verify_cpu_noamd
jnz .Lverify_cpu_noamd
mov $1,%di # cpu is from AMD
jmp verify_cpu_check
jmp .Lverify_cpu_check
verify_cpu_noamd:
.Lverify_cpu_noamd:
cmpl $0x756e6547,%ebx # GenuineIntel?
jnz verify_cpu_check
jnz .Lverify_cpu_check
cmpl $0x49656e69,%edx
jnz verify_cpu_check
jnz .Lverify_cpu_check
cmpl $0x6c65746e,%ecx
jnz verify_cpu_check
jnz .Lverify_cpu_check
# only call IA32_MISC_ENABLE when:
# family > 6 || (family == 6 && model >= 0xd)
@ -83,59 +83,59 @@ verify_cpu_noamd:
andl $0x0ff00f00, %eax # mask family and extended family
shrl $8, %eax
cmpl $6, %eax
ja verify_cpu_clear_xd # family > 6, ok
jb verify_cpu_check # family < 6, skip
ja .Lverify_cpu_clear_xd # family > 6, ok
jb .Lverify_cpu_check # family < 6, skip
andl $0x000f00f0, %ecx # mask model and extended model
shrl $4, %ecx
cmpl $0xd, %ecx
jb verify_cpu_check # family == 6, model < 0xd, skip
jb .Lverify_cpu_check # family == 6, model < 0xd, skip
verify_cpu_clear_xd:
.Lverify_cpu_clear_xd:
movl $MSR_IA32_MISC_ENABLE, %ecx
rdmsr
btrl $2, %edx # clear MSR_IA32_MISC_ENABLE_XD_DISABLE
jnc verify_cpu_check # only write MSR if bit was changed
jnc .Lverify_cpu_check # only write MSR if bit was changed
wrmsr
verify_cpu_check:
.Lverify_cpu_check:
movl $0x1,%eax # Does the cpu have what it takes
cpuid
andl $REQUIRED_MASK0,%edx
xorl $REQUIRED_MASK0,%edx
jnz verify_cpu_no_longmode
jnz .Lverify_cpu_no_longmode
movl $0x80000000,%eax # See if extended cpuid is implemented
cpuid
cmpl $0x80000001,%eax
jb verify_cpu_no_longmode # no extended cpuid
jb .Lverify_cpu_no_longmode # no extended cpuid
movl $0x80000001,%eax # Does the cpu have what it takes
cpuid
andl $REQUIRED_MASK1,%edx
xorl $REQUIRED_MASK1,%edx
jnz verify_cpu_no_longmode
jnz .Lverify_cpu_no_longmode
verify_cpu_sse_test:
.Lverify_cpu_sse_test:
movl $1,%eax
cpuid
andl $SSE_MASK,%edx
cmpl $SSE_MASK,%edx
je verify_cpu_sse_ok
je .Lverify_cpu_sse_ok
test %di,%di
jz verify_cpu_no_longmode # only try to force SSE on AMD
jz .Lverify_cpu_no_longmode # only try to force SSE on AMD
movl $MSR_K7_HWCR,%ecx
rdmsr
btr $15,%eax # enable SSE
wrmsr
xor %di,%di # don't loop
jmp verify_cpu_sse_test # try again
jmp .Lverify_cpu_sse_test # try again
verify_cpu_no_longmode:
.Lverify_cpu_no_longmode:
popf # Restore caller passed flags
movl $1,%eax
ret
verify_cpu_sse_ok:
.Lverify_cpu_sse_ok:
popf # Restore caller passed flags
xorl %eax, %eax
ret