From: Juergen Gross jgross@suse.com
stable inclusion from stable-v5.10.133 commit 341e6178c1cf6225e085de9eaba6216d624d641e 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 e208b3c4a9748b2c17aa09ba663b5096ccf82dce upstream.
Add ALTERNATIVE_TERNARY support for replacing an initial instruction with either of two instructions depending on a feature:
ALTERNATIVE_TERNARY "default_instr", FEATURE_NR, "feature_on_instr", "feature_off_instr"
which will start with "default_instr" and at patch time will, depending on FEATURE_NR being set or not, patch that with either "feature_on_instr" or "feature_off_instr".
[ bp: Add comment ontop. ]
Signed-off-by: Juergen Gross jgross@suse.com Signed-off-by: Borislav Petkov bp@suse.de Acked-by: Peter Zijlstra (Intel) peterz@infradead.org Link: https://lkml.kernel.org/r/20210311142319.4723-7-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/alternative.h | 13 +++++++++++++ 1 file changed, 13 insertions(+)
diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h index c6690d1e1de6..be29b927ff1e 100644 --- a/arch/x86/include/asm/alternative.h +++ b/arch/x86/include/asm/alternative.h @@ -179,6 +179,11 @@ static inline int alternatives_text_reserved(void *start, void *end) ALTINSTR_REPLACEMENT(newinstr2, feature2, 2) \ ".popsection\n"
+/* If @feature is set, patch in @newinstr_yes, otherwise @newinstr_no. */ +#define ALTERNATIVE_TERNARY(oldinstr, feature, newinstr_yes, newinstr_no) \ + ALTERNATIVE_2(oldinstr, newinstr_no, X86_FEATURE_ALWAYS, \ + newinstr_yes, feature) + #define ALTERNATIVE_3(oldinsn, newinsn1, feat1, newinsn2, feat2, newinsn3, feat3) \ OLDINSTR_3(oldinsn, 1, 2, 3) \ ".pushsection .altinstructions,"a"\n" \ @@ -210,6 +215,9 @@ static inline int alternatives_text_reserved(void *start, void *end) #define alternative_2(oldinstr, newinstr1, feature1, newinstr2, feature2) \ asm_inline volatile(ALTERNATIVE_2(oldinstr, newinstr1, feature1, newinstr2, feature2) ::: "memory")
+#define alternative_ternary(oldinstr, feature, newinstr_yes, newinstr_no) \ + asm_inline volatile(ALTERNATIVE_TERNARY(oldinstr, feature, newinstr_yes, newinstr_no) ::: "memory") + /* * Alternative inline assembly with input. * @@ -380,6 +388,11 @@ static inline int alternatives_text_reserved(void *start, void *end) .popsection .endm
+/* If @feature is set, patch in @newinstr_yes, otherwise @newinstr_no. */ +#define ALTERNATIVE_TERNARY(oldinstr, feature, newinstr_yes, newinstr_no) \ + ALTERNATIVE_2 oldinstr, newinstr_no, X86_FEATURE_ALWAYS, \ + newinstr_yes, feature + #endif /* __ASSEMBLY__ */
#endif /* _ASM_X86_ALTERNATIVE_H */