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Tue, 12 Sep 2023 07:17:42 -0700 (PDT) Date: Tue, 12 Sep 2023 14:16:02 +0000 In-Reply-To: <20230912141549.278777-63-ardb@google.com> Mime-Version: 1.0 References: <20230912141549.278777-63-ardb@google.com> X-Developer-Key: i=ardb@kernel.org; a=openpgp; fpr=F43D03328115A198C90016883D200E9CA6329909 X-Developer-Signature: v=1; a=openpgp-sha256; l=3211; i=ardb@kernel.org; h=from:subject; bh=mkUUOQwVOlWxqy3A+z2AA0sKLruJdOeHpAY1GKzvtWw=; b=owGbwMvMwCFmkMcZplerG8N4Wi2JIZWhaNFyY5/AXcdX8jZzakZePqbxevKO4mN8c6fZl1zra FM2+6jQUcrCIMbBICumyCIw+++7nacnStU6z5KFmcPKBDKEgYtTACZixMvIsCFbYXFq2EbZWVU/ NrjHT/nonftNT2/CkhseZ5k66kpljBn+aTz/pxRuZPHdP6/xpmJwTOW/uR2C78TqKu/Xt10W7r3 IDAA= X-Mailer: git-send-email 2.42.0.283.g2d96d420d3-goog Message-ID: <20230912141549.278777-75-ardb@google.com> Subject: [PATCH v4 12/61] arm64: kernel: Don't rely on objcopy to make code under pi/ __init From: Ard Biesheuvel To: linux-arm-kernel@lists.infradead.org Cc: Ard Biesheuvel , Catalin Marinas , Will Deacon , Marc Zyngier , Mark Rutland , Ryan Roberts , Anshuman Khandual , Kees Cook , Joey Gouly X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230912_071744_620304_360CC1E3 X-CRM114-Status: GOOD ( 13.92 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Ard Biesheuvel We will add some code under pi/ that contains global variables that should not end up in __initdata, as they will not be writable via the initial ID map. So only rely on objcopy for making the libfdt code __init, and use explicit annotations for the rest. Signed-off-by: Ard Biesheuvel --- arch/arm64/kernel/pi/Makefile | 6 ++++-- arch/arm64/kernel/pi/kaslr_early.c | 16 +++++++++------- 2 files changed, 13 insertions(+), 9 deletions(-) diff --git a/arch/arm64/kernel/pi/Makefile b/arch/arm64/kernel/pi/Makefile index bc32a431fe35..2bbe866417d4 100644 --- a/arch/arm64/kernel/pi/Makefile +++ b/arch/arm64/kernel/pi/Makefile @@ -28,11 +28,13 @@ quiet_cmd_piobjcopy = $(quiet_cmd_objcopy) cmd_piobjcopy = $(cmd_objcopy) && $(obj)/relacheck $(@) $(<) $(obj)/%.pi.o: OBJCOPYFLAGS := --prefix-symbols=__pi_ \ - --remove-section=.note.gnu.property \ - --prefix-alloc-sections=.init + --remove-section=.note.gnu.property $(obj)/%.pi.o: $(obj)/%.o $(obj)/relacheck FORCE $(call if_changed,piobjcopy) +# ensure that all the lib- code ends up as __init code and data +$(obj)/lib-%.pi.o: OBJCOPYFLAGS += --prefix-alloc-sections=.init + $(obj)/lib-%.o: $(srctree)/lib/%.c FORCE $(call if_changed_rule,cc_o_c) diff --git a/arch/arm64/kernel/pi/kaslr_early.c b/arch/arm64/kernel/pi/kaslr_early.c index b9e0bb4bc6a9..167081b30a15 100644 --- a/arch/arm64/kernel/pi/kaslr_early.c +++ b/arch/arm64/kernel/pi/kaslr_early.c @@ -17,7 +17,7 @@ #include /* taken from lib/string.c */ -static char *__strstr(const char *s1, const char *s2) +static char *__init __strstr(const char *s1, const char *s2) { size_t l1, l2; @@ -33,7 +33,7 @@ static char *__strstr(const char *s1, const char *s2) } return NULL; } -static bool cmdline_contains_nokaslr(const u8 *cmdline) +static bool __init cmdline_contains_nokaslr(const u8 *cmdline) { const u8 *str; @@ -41,7 +41,7 @@ static bool cmdline_contains_nokaslr(const u8 *cmdline) return str == cmdline || (str > cmdline && *(str - 1) == ' '); } -static bool is_kaslr_disabled_cmdline(void *fdt) +static bool __init is_kaslr_disabled_cmdline(void *fdt) { if (!IS_ENABLED(CONFIG_CMDLINE_FORCE)) { int node; @@ -67,17 +67,19 @@ static bool is_kaslr_disabled_cmdline(void *fdt) return cmdline_contains_nokaslr(CONFIG_CMDLINE); } -static u64 get_kaslr_seed(void *fdt) +static u64 __init get_kaslr_seed(void *fdt) { + static char const chosen_str[] __initconst = "chosen"; + static char const seed_str[] __initconst = "kaslr-seed"; int node, len; fdt64_t *prop; u64 ret; - node = fdt_path_offset(fdt, "/chosen"); + node = fdt_path_offset(fdt, chosen_str); if (node < 0) return 0; - prop = fdt_getprop_w(fdt, node, "kaslr-seed", &len); + prop = fdt_getprop_w(fdt, node, seed_str, &len); if (!prop || len != sizeof(u64)) return 0; @@ -86,7 +88,7 @@ static u64 get_kaslr_seed(void *fdt) return ret; } -asmlinkage u64 kaslr_early_init(void *fdt) +asmlinkage u64 __init kaslr_early_init(void *fdt) { u64 seed, range;