From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Garnier via Virtualization Subject: [PATCH v4 12/27] x86/paravirt: Adapt assembly for PIE support Date: Tue, 29 May 2018 15:15:13 -0700 Message-ID: <20180529221625.33541-13-thgarnie@google.com> References: <20180529221625.33541-1-thgarnie@google.com> Reply-To: Thomas Garnier Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180529221625.33541-1-thgarnie@google.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: kernel-hardening@lists.openwall.com Cc: Juergen Gross , x86@kernel.org, linux-kernel@vger.kernel.org, Thomas Garnier , Ingo Molnar , "H. Peter Anvin" , Alok Kataria , virtualization@lists.linux-foundation.org, Thomas Gleixner List-Id: virtualization@lists.linuxfoundation.org if PIE is enabled, switch the paravirt assembly constraints to be compatible. The %c/i constrains generate smaller code so is kept by default. Position Independent Executable (PIE) support will allow to extend the KASLR randomization range 0xffffffff80000000. Signed-off-by: Thomas Garnier --- arch/x86/include/asm/paravirt_types.h | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h index 180bc0bff0fb..140747a98d94 100644 --- a/arch/x86/include/asm/paravirt_types.h +++ b/arch/x86/include/asm/paravirt_types.h @@ -337,9 +337,17 @@ extern struct pv_lock_ops pv_lock_ops; #define PARAVIRT_PATCH(x) \ (offsetof(struct paravirt_patch_template, x) / sizeof(void *)) +#ifdef CONFIG_X86_PIE +#define paravirt_opptr_call "a" +#define paravirt_opptr_type "p" +#else +#define paravirt_opptr_call "c" +#define paravirt_opptr_type "i" +#endif + #define paravirt_type(op) \ [paravirt_typenum] "i" (PARAVIRT_PATCH(op)), \ - [paravirt_opptr] "i" (&(op)) + [paravirt_opptr] paravirt_opptr_type (&(op)) #define paravirt_clobber(clobber) \ [paravirt_clobber] "i" (clobber) @@ -395,7 +403,7 @@ int paravirt_disable_iospace(void); */ #define PARAVIRT_CALL \ ANNOTATE_RETPOLINE_SAFE \ - "call *%c[paravirt_opptr];" + "call *%" paravirt_opptr_call "[paravirt_opptr];" /* * These macros are intended to wrap calls through one of the paravirt -- 2.17.0.921.gf22659ad46-goog