From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DB8C41F8741 for ; Thu, 27 Mar 2025 20:55:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743108902; cv=none; b=IKeIRQqBpvUIBbY5Rp977hxBKuvpWoysGDCTBCtcKbLwyZGevBSJH5RehNOAOlOogUUEARLOx7MS+/Vyx3zRdzD7QqhbrWemMYXuKsJDmCMOFfP0PA1kpolto+I8E3AJN9FwkQoOm5Hjd8ZSBbjauTSmYjN/wX/scArK5GQxjHQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743108902; c=relaxed/simple; bh=bdiwBSo9W6RD9K2588a9gOGZgIRFv+BS8HeSGoR5mdQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WyU1VFc2C0zy+BNY46zhwi34Jn9qPHGuut+9WYgz8Pd8N+6t/M7Bh4EPtN7ny1gDPJ1e5Buvb8jwiZRzucHE3FC63ZqqK+sZe3ul94mT+OGVssaFr7aP36drAFiNKha/pfibth+hA2Jna3QRjuAMLT1Rc5uiaX2zfhNBev18/bg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KbjK632f; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="KbjK632f" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CBC1DC4CEE8; Thu, 27 Mar 2025 20:55:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1743108902; bh=bdiwBSo9W6RD9K2588a9gOGZgIRFv+BS8HeSGoR5mdQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KbjK632fDcy2usClEHmIdVo7Qhwyzm0SWBV2e6aDHbitgBQBCBazaRgC6z6s/Yo2P EmCWbLp0kLZXci88+m5QznMazQt2qMEQWLvA3/xlHLQXdRrw8kXE1zkHHOlZ6bX7z/ hlEYyeHBc8w7J+X1/L/HpwLAHm9h+tFoKJGUy40MzUumD+ldm0sfur9TRs7GA3ZMDQ Go4y/LvbyZrjh1Omt/3o78qwm8LFpaqORc+QNLqfLlSTtlVQdacd2If5iVF1I8akVT hdxrz0Md+Xpe9N68JZRv0XoCgY4/BDU4V41l+VDIzS3D4naHtPcqhqP2omqfJLhE6C iF924132OWQfw== From: Ingo Molnar To: linux-kernel@vger.kernel.org Cc: Juergen Gross , "H . Peter Anvin" , Linus Torvalds , Peter Zijlstra , Borislav Petkov , Thomas Gleixner Subject: [PATCH 26/41] x86/alternatives: Introduce 'struct text_poke_int3_array' and move tp_vec and tp_vec_nr to it Date: Thu, 27 Mar 2025 21:53:39 +0100 Message-ID: <20250327205355.378659-27-mingo@kernel.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20250327205355.378659-1-mingo@kernel.org> References: <20250327205355.378659-1-mingo@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit struct text_poke_array is an equivalent structure to these global variables: static struct text_poke_int3_loc tp_vec[TP_VEC_MAX]; static int tp_vec_nr; Note that we intentionally mirror much of the naming of 'struct text_poke_int3_vec', which will further highlight the unecessary layering going on in this code, and will ease its removal. No change in functionality. Signed-off-by: Ingo Molnar --- arch/x86/kernel/alternative.c | 43 +++++++++++++++++++++++-------------------- 1 file changed, 23 insertions(+), 20 deletions(-) diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index 393d796e797d..cf3bcaa97957 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -2467,14 +2467,21 @@ struct text_poke_int3_loc { }; struct text_poke_int3_vec { - struct text_poke_int3_loc *vec; int nr_entries; + struct text_poke_int3_loc *vec; }; static DEFINE_PER_CPU(atomic_t, int3_refs); static struct text_poke_int3_vec int3_vec; +#define TP_ARRAY_NR_ENTRIES_MAX (PAGE_SIZE / sizeof(struct text_poke_int3_loc)) + +static struct text_poke_int3_array { + int nr_entries; + struct text_poke_int3_loc vec[TP_ARRAY_NR_ENTRIES_MAX]; +} tp_array; + static __always_inline struct text_poke_int3_vec *try_get_desc(void) { @@ -2510,10 +2517,6 @@ static __always_inline int patch_cmp(const void *key, const void *elt) return 0; } -#define TP_VEC_MAX (PAGE_SIZE / sizeof(struct text_poke_int3_loc)) -static struct text_poke_int3_loc tp_vec[TP_VEC_MAX]; -static int tp_vec_nr; - noinstr int text_poke_int3_handler(struct pt_regs *regs) { struct text_poke_int3_vec *desc; @@ -2538,7 +2541,7 @@ noinstr int text_poke_int3_handler(struct pt_regs *regs) if (!desc) return 0; - WARN_ON_ONCE(desc->vec != tp_vec); + WARN_ON_ONCE(desc->vec != tp_array.vec); /* * Discount the INT3. See text_poke_int3_batch(). @@ -2627,8 +2630,8 @@ static void text_poke_int3_batch(struct text_poke_int3_loc *tp, unsigned int nr_ lockdep_assert_held(&text_mutex); - WARN_ON_ONCE(tp != tp_vec); - WARN_ON_ONCE(nr_entries != tp_vec_nr); + WARN_ON_ONCE(tp != tp_array.vec); + WARN_ON_ONCE(nr_entries != tp_array.nr_entries); int3_vec.vec = tp; int3_vec.nr_entries = nr_entries; @@ -2843,7 +2846,7 @@ static void text_poke_int3_loc_init(struct text_poke_int3_loc *tp, void *addr, } /* - * We hard rely on the tp_vec being ordered; ensure this is so by flushing + * We hard rely on the tp_array.vec being ordered; ensure this is so by flushing * early if needed. */ static bool tp_addr_ordered(void *addr) @@ -2852,7 +2855,7 @@ static bool tp_addr_ordered(void *addr) WARN_ON_ONCE(!addr); - if (!tp_vec_nr) + if (!tp_array.nr_entries) return true; /* @@ -2861,7 +2864,7 @@ static bool tp_addr_ordered(void *addr) * is violated and we must first flush all pending patching * requests: */ - tp = &tp_vec[tp_vec_nr-1]; + tp = &tp_array.vec[tp_array.nr_entries-1]; if ((unsigned long)text_poke_int3_addr(tp) > (unsigned long)addr) return false; @@ -2870,9 +2873,9 @@ static bool tp_addr_ordered(void *addr) void text_poke_int3_finish(void) { - if (tp_vec_nr) { - text_poke_int3_batch(tp_vec, tp_vec_nr); - tp_vec_nr = 0; + if (tp_array.nr_entries) { + text_poke_int3_batch(tp_array.vec, tp_array.nr_entries); + tp_array.nr_entries = 0; } } @@ -2880,9 +2883,9 @@ static void text_poke_int3_flush(void *addr) { lockdep_assert_held(&text_mutex); - if (tp_vec_nr == TP_VEC_MAX || !tp_addr_ordered(addr)) { - text_poke_int3_batch(tp_vec, tp_vec_nr); - tp_vec_nr = 0; + if (tp_array.nr_entries == TP_ARRAY_NR_ENTRIES_MAX || !tp_addr_ordered(addr)) { + text_poke_int3_batch(tp_array.vec, tp_array.nr_entries); + tp_array.nr_entries = 0; } } @@ -2892,7 +2895,7 @@ void __ref text_poke_int3_queue(void *addr, const void *opcode, size_t len, cons text_poke_int3_flush(addr); - tp = &tp_vec[tp_vec_nr++]; + tp = &tp_array.vec[tp_array.nr_entries++]; text_poke_int3_loc_init(tp, addr, opcode, len, emulate); } @@ -2912,9 +2915,9 @@ void __ref text_poke_int3(void *addr, const void *opcode, size_t len, const void struct text_poke_int3_loc *tp; /* Batch-patching should not be mixed with single-patching: */ - WARN_ON_ONCE(tp_vec_nr != 0); + WARN_ON_ONCE(tp_array.nr_entries != 0); - tp = &tp_vec[tp_vec_nr++]; + tp = &tp_array.vec[tp_array.nr_entries++]; text_poke_int3_loc_init(tp, addr, opcode, len, emulate); text_poke_int3_finish(); -- 2.45.2