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[37.24.206.209]) by smtp.gmail.com with ESMTPSA id j27-20020adfb31b000000b00336e32338f3sm12166221wrd.70.2024.01.15.06.40.19 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 15 Jan 2024 06:40:20 -0800 (PST) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 0244fda4-b3b4-11ee-98f1-6d05b1d4d9a1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1705329620; x=1705934420; darn=lists.xenproject.org; h=content-transfer-encoding:in-reply-to:autocrypt:references:cc:to :from:content-language:subject:user-agent:mime-version:date :message-id:from:to:cc:subject:date:message-id:reply-to; bh=PGc0X6Yaf/cUmP7O9RP4fKCBRUMgrpx1/OYaXtfQg1k=; b=c8rwg4O9FQDUsc73rQ9+joRT4ZCz3fCZtRYWADVeG7JsmgG3/DMUmjwcWvZSAM0WSb MvPEnJTg9pPy9iX6vEgkha8lB0obPYCWaURVQmnS0V+4VGTA1DdY/GgB7WP8s0zaoCeX NO1UT7f9mOVLLqHw+/Zwj9cM0Ot2SAON/0EIvJ1Q8rYehbd+xhEDlwWGCnZyVOFfUaDF 5WhDdkJ/ncKLqZZSFFXL99UiPwVOcO0C/SJ9+3nXQRfJF9tyjAsRv7pKxbFdtpuuk+O4 pFoY9HdHG6Xb75Z5s8TxYiR1oFIBrUkVsiLu7DR81GwUwRFqDrKJV40AGuA8qZMrhX4u swAQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1705329620; x=1705934420; h=content-transfer-encoding:in-reply-to:autocrypt:references:cc:to :from:content-language:subject:user-agent:mime-version:date :message-id:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=PGc0X6Yaf/cUmP7O9RP4fKCBRUMgrpx1/OYaXtfQg1k=; b=BS6C0IAbcIwfE7z8LGUL7QJF27TxQvB+a1B67kS/1+Ryw4H1fCRfK2PmxhQflYBPpX TB8AuzWaBfY/eDZOQHMlWE7FZ61/yyMEWP2WLMlCtPv1nkee996wIBGfjYURZBFxNRUh HnwFqPBGC6aYQfl7rnU93bKY9wiXMNHDjVFGmAwAnpfEvDuY42r4tvU6E6vPoMyzKMB8 TTe7Z5Jf2TJc+ZyWGxtuEemvs0Sm2Pv5aQHNLn5HfjWqnvv0a5QF8zmAkKeexNTY5ix1 HE9VtdR6cGYAXFN8jbu7hAatcTUcJuaypcLVheDwZOVUj0cg+fYrt+3U9RPhMtzCOvKR yftQ== X-Gm-Message-State: AOJu0YwOY36IH+ZJmPyHDsmTAB4ASabeynI1NxL+3eIOHh3wLlfER/ls QXhJNFzNcSPJ1iS+lz8sXKD2Dp7Ohik6Tv9Fhy8OCZkYpA== X-Google-Smtp-Source: AGHT+IEoPhR57xV8FSVKgZ6TMjy/XaNhigGL4lCN5GQks/jeVjwsFpysbxkv5z0/PeovruV90mmC5g== X-Received: by 2002:a5d:67cc:0:b0:337:4ce2:a601 with SMTP id n12-20020a5d67cc000000b003374ce2a601mr3282252wrw.76.1705329620403; Mon, 15 Jan 2024 06:40:20 -0800 (PST) Message-ID: <5df1d87d-8e54-4e15-b1fb-46b274cb66ef@suse.com> Date: Mon, 15 Jan 2024 15:40:19 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: [PATCH v5 8/8] common: honor CONFIG_CC_SPLIT_SECTIONS also for assembly functions Content-Language: en-US From: Jan Beulich To: "xen-devel@lists.xenproject.org" Cc: Andrew Cooper , Wei Liu , =?utf-8?q?Roger_Pau_Monn=C3=A9?= , Julien Grall , Stefano Stabellini , Volodymyr Babchuk , Bertrand Marquis , Bobby Eshleman , Alistair Francis , Connor Davis , George Dunlap , Shawn Anastasio , Michal Orzel References: <7a133ed9-9d13-4e2c-893a-00c083c8a35d@suse.com> Autocrypt: addr=jbeulich@suse.com; keydata= xsDiBFk3nEQRBADAEaSw6zC/EJkiwGPXbWtPxl2xCdSoeepS07jW8UgcHNurfHvUzogEq5xk hu507c3BarVjyWCJOylMNR98Yd8VqD9UfmX0Hb8/BrA+Hl6/DB/eqGptrf4BSRwcZQM32aZK 7Pj2XbGWIUrZrd70x1eAP9QE3P79Y2oLrsCgbZJfEwCgvz9JjGmQqQkRiTVzlZVCJYcyGGsD /0tbFCzD2h20ahe8rC1gbb3K3qk+LpBtvjBu1RY9drYk0NymiGbJWZgab6t1jM7sk2vuf0Py O9Hf9XBmK0uE9IgMaiCpc32XV9oASz6UJebwkX+zF2jG5I1BfnO9g7KlotcA/v5ClMjgo6Gl MDY4HxoSRu3i1cqqSDtVlt+AOVBJBACrZcnHAUSuCXBPy0jOlBhxPqRWv6ND4c9PH1xjQ3NP nxJuMBS8rnNg22uyfAgmBKNLpLgAGVRMZGaGoJObGf72s6TeIqKJo/LtggAS9qAUiuKVnygo 3wjfkS9A3DRO+SpU7JqWdsveeIQyeyEJ/8PTowmSQLakF+3fote9ybzd880fSmFuIEJldWxp Y2ggPGpiZXVsaWNoQHN1c2UuY29tPsJgBBMRAgAgBQJZN5xEAhsDBgsJCAcDAgQVAggDBBYC AwECHgECF4AACgkQoDSui/t3IH4J+wCfQ5jHdEjCRHj23O/5ttg9r9OIruwAn3103WUITZee e7Sbg12UgcQ5lv7SzsFNBFk3nEQQCACCuTjCjFOUdi5Nm244F+78kLghRcin/awv+IrTcIWF hUpSs1Y91iQQ7KItirz5uwCPlwejSJDQJLIS+QtJHaXDXeV6NI0Uef1hP20+y8qydDiVkv6l IreXjTb7DvksRgJNvCkWtYnlS3mYvQ9NzS9PhyALWbXnH6sIJd2O9lKS1Mrfq+y0IXCP10eS FFGg+Av3IQeFatkJAyju0PPthyTqxSI4lZYuJVPknzgaeuJv/2NccrPvmeDg6Coe7ZIeQ8Yj t0ARxu2xytAkkLCel1Lz1WLmwLstV30g80nkgZf/wr+/BXJW/oIvRlonUkxv+IbBM3dX2OV8 AmRv1ySWPTP7AAMFB/9PQK/VtlNUJvg8GXj9ootzrteGfVZVVT4XBJkfwBcpC/XcPzldjv+3 HYudvpdNK3lLujXeA5fLOH+Z/G9WBc5pFVSMocI71I8bT8lIAzreg0WvkWg5V2WZsUMlnDL9 mpwIGFhlbM3gfDMs7MPMu8YQRFVdUvtSpaAs8OFfGQ0ia3LGZcjA6Ik2+xcqscEJzNH+qh8V m5jjp28yZgaqTaRbg3M/+MTbMpicpZuqF4rnB0AQD12/3BNWDR6bmh+EkYSMcEIpQmBM51qM EKYTQGybRCjpnKHGOxG0rfFY1085mBDZCH5Kx0cl0HVJuQKC+dV2ZY5AqjcKwAxpE75MLFkr wkkEGBECAAkFAlk3nEQCGwwACgkQoDSui/t3IH7nnwCfcJWUDUFKdCsBH/E5d+0ZnMQi+G0A nAuWpQkjM1ASeQwSHEeAWPgskBQL In-Reply-To: <7a133ed9-9d13-4e2c-893a-00c083c8a35d@suse.com> Leverage the new infrastructure in xen/linkage.h to also switch to per- function sections (when configured), deriving the specific name from the "base" section in use at the time FUNC() is invoked. Signed-off-by: Jan Beulich --- TBD: Since we use .subsection in UNLIKELY_START(), a perhaps not really wanted side effect of this change is that respective out-of-line code now moves much closer to its original (invoking) code. TBD: Of course something with the same overall effect, but less impactful might do in Config.mk. E.g. $(filter-out -D%,$(3)) instead of $(firstword (3)). TBD: On top of Roger's respective patch (for livepatch), also respect CONFIG_FUNCTION_ALIGNMENT. Note that we'd need to split DATA() in order to separate r/w and r/o contributions. Further splitting might be needed to also support more advanced attributes (e.g. merge), hence why this isn't done right here. Sadly while a new section's name can be derived from the presently in use, its attributes cannot be. Perhaps the only thing we can do is give DATA() a 2nd mandatory parameter. Then again I guess most data definitions could be moved to C anyway. --- v5: Re-base over changes earlier in the series. v4: Re-base. v2: Make detection properly fail on old gas (by adjusting cc-option-add-closure). --- a/Config.mk +++ b/Config.mk @@ -102,7 +102,7 @@ cc-option = $(shell if $(1) $(2:-Wno-%=- # Usage: $(call cc-option-add CFLAGS,CC,-march=winchip-c6) cc-option-add = $(eval $(call cc-option-add-closure,$(1),$(2),$(3))) define cc-option-add-closure - ifneq ($$(call cc-option,$$($(2)),$(3),n),n) + ifneq ($$(call cc-option,$$($(2)),$(firstword $(3)),n),n) $(1) += $(3) endif endef --- a/xen/Makefile +++ b/xen/Makefile @@ -409,6 +409,9 @@ AFLAGS += -D__ASSEMBLY__ $(call cc-option-add,AFLAGS,CC,-Wa$$(comma)--noexecstack) +# Check to see whether the assmbler supports the --sectname-subst option. +$(call cc-option-add,AFLAGS,CC,-Wa$$(comma)--sectname-subst -DHAVE_AS_SECTNAME_SUBST) + LDFLAGS-$(call ld-option,--warn-rwx-segments) += --no-warn-rwx-segments CFLAGS += $(CFLAGS-y) --- a/xen/arch/arm/xen.lds.S +++ b/xen/arch/arm/xen.lds.S @@ -156,6 +156,9 @@ SECTIONS .init.text : { _sinittext = .; *(.init.text) +#ifdef CONFIG_CC_SPLIT_SECTIONS + *(.init.text.*) +#endif _einittext = .; . = ALIGN(PAGE_SIZE); /* Avoid mapping alt insns executable */ *(.altinstr_replacement) --- a/xen/arch/ppc/xen.lds.S +++ b/xen/arch/ppc/xen.lds.S @@ -104,6 +104,9 @@ SECTIONS .init.text : { _sinittext = .; *(.init.text) +#ifdef CONFIG_CC_SPLIT_SECTIONS + *(.init.text.*) +#endif _einittext = .; . = ALIGN(PAGE_SIZE); /* Avoid mapping alt insns executable */ } :text --- a/xen/arch/riscv/xen.lds.S +++ b/xen/arch/riscv/xen.lds.S @@ -104,6 +104,9 @@ SECTIONS .init.text : { _sinittext = .; *(.init.text) +#ifdef CONFIG_CC_SPLIT_SECTIONS + *(.init.text.*) +#endif _einittext = .; . = ALIGN(PAGE_SIZE); /* Avoid mapping alt insns executable */ } :text --- a/xen/arch/x86/xen.lds.S +++ b/xen/arch/x86/xen.lds.S @@ -86,6 +86,9 @@ SECTIONS . = ALIGN(PAGE_SIZE); _stextentry = .; *(.text.entry) +#ifdef CONFIG_CC_SPLIT_SECTIONS + *(.text.entry.*) +#endif . = ALIGN(PAGE_SIZE); _etextentry = .; @@ -214,6 +217,9 @@ SECTIONS #endif _sinittext = .; *(.init.text) +#ifdef CONFIG_CC_SPLIT_SECTIONS + *(.init.text.*) +#endif *(.text.startup) _einittext = .; /* --- a/xen/include/xen/linkage.h +++ b/xen/include/xen/linkage.h @@ -19,6 +19,14 @@ #define SYM_ALIGN(align...) .balign align +#if defined(HAVE_AS_SECTNAME_SUBST) && defined(CONFIG_CC_SPLIT_SECTIONS) +# define SYM_PUSH_SECTION(name, attr) \ + .pushsection %S.name, attr, %progbits; \ + .equ .Lsplit_section, 1 +#else +# define SYM_PUSH_SECTION(name, attr) +#endif + #define SYM_L_GLOBAL(name) .globl name; .hidden name #define SYM_L_WEAK(name) .weak name #define SYM_L_LOCAL(name) /* nothing */ @@ -33,7 +41,14 @@ SYM_ALIGN(align); \ name: -#define END(name) .size name, . - name +#define END(name) \ + .size name, . - name; \ + .ifdef .Lsplit_section; \ + .if .Lsplit_section; \ + .popsection; \ + .equ .Lsplit_section, 0; \ + .endif; \ + .endif /* * CODE_FILL in particular may need to expand to nothing (e.g. for RISC-V), in @@ -47,6 +62,7 @@ #endif #define FUNC(name, align...) \ + SYM_PUSH_SECTION(name, "ax"); \ SYM(name, FUNC, GLOBAL, DO_CODE_ALIGN(align)) #define LABEL(name, align...) \ SYM(name, NONE, GLOBAL, DO_CODE_ALIGN(align)) @@ -54,6 +70,7 @@ SYM(name, DATA, GLOBAL, LASTARG(DATA_ALIGN, ## align), DATA_FILL) #define FUNC_LOCAL(name, align...) \ + SYM_PUSH_SECTION(name, "ax"); \ SYM(name, FUNC, LOCAL, DO_CODE_ALIGN(align)) #define LABEL_LOCAL(name, align...) \ SYM(name, NONE, LOCAL, DO_CODE_ALIGN(align))