From: Nick Desaulniers <ndesaulniers@google.com> To: akpm@linux-foundation.org, hpa@zytor.com, mingo@redhat.com, tglx@linutronix.de Cc: linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org, virtualization@lists.linux-foundation.org, astrachan@google.com, manojgupta@google.com, ghackmann@google.com, sedat.dilek@gmail.com, tstellar@redhat.com, keescook@google.com, yamada.masahiro@socionext.com, michal.lkml@markovi.net, linux-kbuild@vger.kernel.org, geert@linux-m68k.org, will.deacon@arm.com, mawilcox@microsoft.com, arnd@arndb.de, rientjes@google.com, acme@redhat.com, pombredanne@nexb.com, aryabinin@virtuozzo.com, kstewart@linuxfoundation.org, boris.ostrovsky@oracle.com, jan.kiszka@siemens.com, rostedt@goodmis.org, kirill.shutemov@linux.intel.com, ard.biesheuvel@linaro.org, akataria@vmware.com, brijesh.singh@amd.com, caoj.fnst@cn.fujitsu.com, gregkh@linuxfoundation.org, jarkko.sakkinen@linux.intel.com, jgross@suse.com, jpoimboe@redhat.com, mka@chromium.org, ndesaulniers@google.com, thomas.lendacky@amd.com, tweek@google.com, mjg59@google.com, joe@perches.com Subject: [PATCH v3 0/3] extern inline native_save_fl for paravirt Date: Thu, 7 Jun 2018 11:32:16 -0700 [thread overview] Message-ID: <20180607183219.192973-1-ndesaulniers@google.com> (raw) paravirt depends on a custom calling convention (callee saved), but expects this from a static inline function that it then forces to be outlined. This is problematic because different compilers or flags can then add a stack guard that violates the calling conventions. Uses extern inline with the out-of-line definition in assembly to prevent compilers from adding stack guards to the outlined version. Other parts of the codebase overwrite KBUILD_CFLAGS, which is *extremely problematic* for extern inline, as the sematics are completely the opposite depending on what C standard is used. http://blahg.josefsipek.net/?p=529 Changes since v2: Take hpa's _ASM_ARG patch into the set in order to simplify cross 32b/64b x86 assembly. Apply Sedat's typo fix to commit message and sign off on it. Take Joe's sugguestion to simplify __inline__ and __inline. Add Arnd to list of folks who made helpful suggestions. Changes since v1: Prefer gnu_inline function attribute instead of explicitly setting C standard compiler flag in problematic Makefiles. We should instead carefully evaluate if those Makefiles should be overwriting KBUILD_CFLAGS at all. Dropped the previous first two patches and added a new first patch. H. Peter Anvin (1): x86/asm: add _ASM_ARG* constants for argument registers to <asm/asm.h> Nick Desaulniers (2): compiler-gcc.h: add gnu_inline to all inline declarations x86: paravirt: make native_save_fl extern inline arch/x86/include/asm/asm.h | 59 +++++++++++++++++++++++++++++++++ arch/x86/include/asm/irqflags.h | 2 +- arch/x86/kernel/Makefile | 1 + arch/x86/kernel/irqflags.S | 26 +++++++++++++++ include/linux/compiler-gcc.h | 17 ++++++---- 5 files changed, 98 insertions(+), 7 deletions(-) create mode 100644 arch/x86/kernel/irqflags.S -- 2.17.1.1185.g55be947832-goog
WARNING: multiple messages have this Message-ID (diff)
From: Nick Desaulniers <ndesaulniers@google.com> To: akpm@linux-foundation.org, hpa@zytor.com, mingo@redhat.com, tglx@linutronix.de Cc: linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org, virtualization@lists.linux-foundation.org, astrachan@google.com, manojgupta@google.com, ghackmann@google.com, sedat.dilek@gmail.com, tstellar@redhat.com, keescook@google.com, yamada.masahiro@socionext.com, michal.lkml@markovi.net, linux-kbuild@vger.kernel.org, geert@linux-m68k.org, will.deacon@arm.com, mawilcox@microsoft.com, arnd@arndb.de, rientjes@google.com, acme@redhat.com, pombredanne@nexb.com, aryabinin@virtuozzo.com, kstewart@linuxfoundation.org, boris.ostrovsky@oracle.com, jan.kiszka@siemens.com, rostedt@goodmis.org, kirill.shutemov@linux.intel.com, ard.biesheuvel@linaro.org, akataria@vmware.com, brijesh.singh@amd.com, caoj.fnst@cn.fujitsu.com, gregkh@linuxfoundation.org, jarkko.sakkinen@linux.intel.co Subject: [PATCH v3 0/3] extern inline native_save_fl for paravirt Date: Thu, 7 Jun 2018 11:32:16 -0700 [thread overview] Message-ID: <20180607183219.192973-1-ndesaulniers@google.com> (raw) paravirt depends on a custom calling convention (callee saved), but expects this from a static inline function that it then forces to be outlined. This is problematic because different compilers or flags can then add a stack guard that violates the calling conventions. Uses extern inline with the out-of-line definition in assembly to prevent compilers from adding stack guards to the outlined version. Other parts of the codebase overwrite KBUILD_CFLAGS, which is *extremely problematic* for extern inline, as the sematics are completely the opposite depending on what C standard is used. http://blahg.josefsipek.net/?p=529 Changes since v2: Take hpa's _ASM_ARG patch into the set in order to simplify cross 32b/64b x86 assembly. Apply Sedat's typo fix to commit message and sign off on it. Take Joe's sugguestion to simplify __inline__ and __inline. Add Arnd to list of folks who made helpful suggestions. Changes since v1: Prefer gnu_inline function attribute instead of explicitly setting C standard compiler flag in problematic Makefiles. We should instead carefully evaluate if those Makefiles should be overwriting KBUILD_CFLAGS at all. Dropped the previous first two patches and added a new first patch. H. Peter Anvin (1): x86/asm: add _ASM_ARG* constants for argument registers to <asm/asm.h> Nick Desaulniers (2): compiler-gcc.h: add gnu_inline to all inline declarations x86: paravirt: make native_save_fl extern inline arch/x86/include/asm/asm.h | 59 +++++++++++++++++++++++++++++++++ arch/x86/include/asm/irqflags.h | 2 +- arch/x86/kernel/Makefile | 1 + arch/x86/kernel/irqflags.S | 26 +++++++++++++++ include/linux/compiler-gcc.h | 17 ++++++---- 5 files changed, 98 insertions(+), 7 deletions(-) create mode 100644 arch/x86/kernel/irqflags.S -- 2.17.1.1185.g55be947832-goog
next reply other threads:[~2018-06-07 18:32 UTC|newest] Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-06-07 18:32 Nick Desaulniers [this message] 2018-06-07 18:32 ` [PATCH v3 0/3] extern inline native_save_fl for paravirt Nick Desaulniers 2018-06-07 18:32 ` [PATCH v3 1/3] compiler-gcc.h: add gnu_inline to all inline declarations Nick Desaulniers 2018-06-07 18:32 ` Nick Desaulniers 2018-06-07 18:43 ` Joe Perches 2018-06-07 18:43 ` Joe Perches 2018-06-07 18:43 ` Joe Perches 2018-06-07 18:32 ` [PATCH v3 2/3] x86/asm: add _ASM_ARG* constants for argument registers to <asm/asm.h> Nick Desaulniers 2018-06-07 18:32 ` Nick Desaulniers 2018-06-07 20:13 ` H. Peter Anvin 2018-06-07 20:13 ` H. Peter Anvin 2018-06-07 20:13 ` H. Peter Anvin 2018-06-07 20:15 ` Nick Desaulniers 2018-06-07 20:15 ` Nick Desaulniers 2018-06-07 18:32 ` [PATCH v3 3/3] x86: paravirt: make native_save_fl extern inline Nick Desaulniers 2018-06-07 18:32 ` Nick Desaulniers 2018-06-07 18:39 ` Nick Desaulniers 2018-06-07 18:39 ` Nick Desaulniers
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20180607183219.192973-1-ndesaulniers@google.com \ --to=ndesaulniers@google.com \ --cc=acme@redhat.com \ --cc=akataria@vmware.com \ --cc=akpm@linux-foundation.org \ --cc=ard.biesheuvel@linaro.org \ --cc=arnd@arndb.de \ --cc=aryabinin@virtuozzo.com \ --cc=astrachan@google.com \ --cc=boris.ostrovsky@oracle.com \ --cc=brijesh.singh@amd.com \ --cc=caoj.fnst@cn.fujitsu.com \ --cc=geert@linux-m68k.org \ --cc=ghackmann@google.com \ --cc=gregkh@linuxfoundation.org \ --cc=hpa@zytor.com \ --cc=jan.kiszka@siemens.com \ --cc=jarkko.sakkinen@linux.intel.com \ --cc=jgross@suse.com \ --cc=joe@perches.com \ --cc=jpoimboe@redhat.com \ --cc=keescook@google.com \ --cc=kirill.shutemov@linux.intel.com \ --cc=kstewart@linuxfoundation.org \ --cc=linux-efi@vger.kernel.org \ --cc=linux-kbuild@vger.kernel.org \ --cc=linux-kernel@vger.kernel.org \ --cc=manojgupta@google.com \ --cc=mawilcox@microsoft.com \ --cc=michal.lkml@markovi.net \ --cc=mingo@redhat.com \ --cc=mjg59@google.com \ --cc=mka@chromium.org \ --cc=pombredanne@nexb.com \ --cc=rientjes@google.com \ --cc=rostedt@goodmis.org \ --cc=sedat.dilek@gmail.com \ --cc=tglx@linutronix.de \ --cc=thomas.lendacky@amd.com \ --cc=tstellar@redhat.com \ --cc=tweek@google.com \ --cc=virtualization@lists.linux-foundation.org \ --cc=will.deacon@arm.com \ --cc=x86@kernel.org \ --cc=yamada.masahiro@socionext.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.