From: Juergen Gross jgross@suse.com
stable inclusion from stable-v5.10.133 commit fd80da64cffe952cfd71c1c60085ad2bad7ecb63 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5PTAS CVE: CVE-2022-29900,CVE-2022-23816,CVE-2022-29901
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit 2fe2a2c7a97c9bc32acc79154b75e754280f7867 upstream.
_static_cpu_has() contains a completely open coded version of ALTERNATIVE_TERNARY(). Replace that with the macro instead.
Signed-off-by: Juergen Gross jgross@suse.com Signed-off-by: Borislav Petkov bp@suse.de Link: https://lkml.kernel.org/r/20210311142319.4723-8-jgross@suse.com Signed-off-by: Ben Hutchings ben@decadent.org.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Lin Yujun linyujun809@huawei.com Reviewed-by: Zhang Jianhua chris.zjh@huawei.com --- arch/x86/include/asm/cpufeature.h | 41 +++++++------------------------ 1 file changed, 9 insertions(+), 32 deletions(-)
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h index 59bf91c57aa8..b9490f462d01 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -8,6 +8,7 @@
#include <asm/asm.h> #include <linux/bitops.h> +#include <asm/alternative.h>
enum cpuid_leafs { @@ -172,39 +173,15 @@ extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit); */ static __always_inline bool _static_cpu_has(u16 bit) { - asm_volatile_goto("1: jmp 6f\n" - "2:\n" - ".skip -(((5f-4f) - (2b-1b)) > 0) * " - "((5f-4f) - (2b-1b)),0x90\n" - "3:\n" - ".section .altinstructions,"a"\n" - " .long 1b - .\n" /* src offset */ - " .long 4f - .\n" /* repl offset */ - " .word %P[always]\n" /* always replace */ - " .byte 3b - 1b\n" /* src len */ - " .byte 5f - 4f\n" /* repl len */ - " .byte 3b - 2b\n" /* pad len */ - ".previous\n" - ".section .altinstr_replacement,"ax"\n" - "4: jmp %l[t_no]\n" - "5:\n" - ".previous\n" - ".section .altinstructions,"a"\n" - " .long 1b - .\n" /* src offset */ - " .long 0\n" /* no replacement */ - " .word %P[feature]\n" /* feature bit */ - " .byte 3b - 1b\n" /* src len */ - " .byte 0\n" /* repl len */ - " .byte 0\n" /* pad len */ - ".previous\n" - ".section .altinstr_aux,"ax"\n" - "6:\n" - " testb %[bitnum],%[cap_byte]\n" - " jnz %l[t_yes]\n" - " jmp %l[t_no]\n" - ".previous\n" + asm_volatile_goto( + ALTERNATIVE_TERNARY("jmp 6f", %P[feature], "", "jmp %l[t_no]") + ".section .altinstr_aux,"ax"\n" + "6:\n" + " testb %[bitnum],%[cap_byte]\n" + " jnz %l[t_yes]\n" + " jmp %l[t_no]\n" + ".previous\n" : : [feature] "i" (bit), - [always] "i" (X86_FEATURE_ALWAYS), [bitnum] "i" (1 << (bit & 7)), [cap_byte] "m" (((const char *)boot_cpu_data.x86_capability)[bit >> 3]) : : t_yes, t_no);