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 74651218593 for ; Mon, 9 Jun 2025 19:35:32 +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=1749497733; cv=none; b=oLWA+OXenbG4MS1hZ4SyIYjXpG8ebfIRbVmfK3Ndx9AGmNurW2nmojTA6nEQdn61AelaJugIxrJq4ciH/FcdAmtGSIPlD2BJEm4phzwgNceTvrgmF6J9NKcKzLJmxdWAhuFMc+M81i575OMNP27YXUPzxavPT5tVP+pWbFofJMw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749497733; c=relaxed/simple; bh=R3gU90omsftkVdeSkjUJZA4IL0k+9038HjR1FpKShN8=; h=Date:To:From:Subject:Message-Id; b=AUhhioHNjGXEcGddALJc+ybDSIV+iCstA42KS89lDAOPHkXe/+5d85/z9thjgOoEec17tTNblvrvBx0BL3LxqjB88ASRRmK3Ord+ofWCoGu0NXwm47UgBIcYxea8fa9GA6MN6J4Kj7Rud9ik04oY3HSBzrvwFbd9DSbFpSgNYP4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=LeHPBNbR; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="LeHPBNbR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B653BC4CEEB; Mon, 9 Jun 2025 19:35:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1749497732; bh=R3gU90omsftkVdeSkjUJZA4IL0k+9038HjR1FpKShN8=; h=Date:To:From:Subject:From; b=LeHPBNbRH2jimkjqkwF64w3uha0dturcG6WR9+XBYLGdpwmPUOKHQmfc3m/6OsjsF mmEAEIBqEsXngbiUUzcSltPfQ0AdU6vHeak0SYxeSzW1z5ePwIBEZvdYGbNYejpGi2 nWdMCToKLQrlXU8u3QRUOC9LEz2p32G6TG2krbUo= Date: Mon, 09 Jun 2025 12:35:32 -0700 To: mm-commits@vger.kernel.org,rppt@kernel.org,mjguzik@gmail.com,linus.walleij@linaro.org,pasha.tatashin@soleen.com,akpm@linux-foundation.org From: Andrew Morton Subject: + fork-clean-up-naming-of-vm_stack-vm_struct-variables-in-vmap-stacks-code.patch added to mm-nonmm-unstable branch Message-Id: <20250609193532.B653BC4CEEB@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: fork: clean-up naming of vm_stack/vm_struct variables in vmap stacks code has been added to the -mm mm-nonmm-unstable branch. Its filename is fork-clean-up-naming-of-vm_stack-vm_struct-variables-in-vmap-stacks-code.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/fork-clean-up-naming-of-vm_stack-vm_struct-variables-in-vmap-stacks-code.patch This patch will later appear in the mm-nonmm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Pasha Tatashin Subject: fork: clean-up naming of vm_stack/vm_struct variables in vmap stacks code Date: Fri, 09 May 2025 08:29:27 +0200 There are two data types: "struct vm_struct" and "struct vm_stack" that have the same local variable names: vm_stack, or vm, or s, which makes the code confusing to read. Change the code so the naming is consistent: struct vm_struct is always called vm_area struct vm_stack is always called vm_stack One change altering vfree(vm_stack) to vfree(vm_area->addr) may look like a semantic change but it is not: vm_area->addr points to the vm_stack. This was done to improve readability. [linus.walleij@linaro.org: rebased and added new users of the variable names, address review comments] Link: https://lore.kernel.org/20240311164638.2015063-4-pasha.tatashin@soleen.com Link: https://lkml.kernel.org/r/20250509-fork-fixes-v3-2-e6c69dd356f2@linaro.org Signed-off-by: Pasha Tatashin Signed-off-by: Linus Walleij Acked-by: Mike Rapoport (Microsoft) Cc: Mateusz Guzik Signed-off-by: Andrew Morton --- kernel/fork.c | 60 +++++++++++++++++++++++------------------------- 1 file changed, 29 insertions(+), 31 deletions(-) --- a/kernel/fork.c~fork-clean-up-naming-of-vm_stack-vm_struct-variables-in-vmap-stacks-code +++ a/kernel/fork.c @@ -207,14 +207,14 @@ struct vm_stack { struct vm_struct *stack_vm_area; }; -static bool try_release_thread_stack_to_cache(struct vm_struct *vm) +static bool try_release_thread_stack_to_cache(struct vm_struct *vm_area) { unsigned int i; for (i = 0; i < NR_CACHED_STACKS; i++) { struct vm_struct *tmp = NULL; - if (this_cpu_try_cmpxchg(cached_stacks[i], &tmp, vm)) + if (this_cpu_try_cmpxchg(cached_stacks[i], &tmp, vm_area)) return true; } return false; @@ -223,11 +223,12 @@ static bool try_release_thread_stack_to_ static void thread_stack_free_rcu(struct rcu_head *rh) { struct vm_stack *vm_stack = container_of(rh, struct vm_stack, rcu); + struct vm_struct *vm_area = vm_stack->stack_vm_area; if (try_release_thread_stack_to_cache(vm_stack->stack_vm_area)) return; - vfree(vm_stack); + vfree(vm_area->addr); } static void thread_stack_delayed_free(struct task_struct *tsk) @@ -240,32 +241,32 @@ static void thread_stack_delayed_free(st static int free_vm_stack_cache(unsigned int cpu) { - struct vm_struct **cached_vm_stacks = per_cpu_ptr(cached_stacks, cpu); + struct vm_struct **cached_vm_stack_areas = per_cpu_ptr(cached_stacks, cpu); int i; for (i = 0; i < NR_CACHED_STACKS; i++) { - struct vm_struct *vm_stack = cached_vm_stacks[i]; + struct vm_struct *vm_area = cached_vm_stack_areas[i]; - if (!vm_stack) + if (!vm_area) continue; - vfree(vm_stack->addr); - cached_vm_stacks[i] = NULL; + vfree(vm_area->addr); + cached_vm_stack_areas[i] = NULL; } return 0; } -static int memcg_charge_kernel_stack(struct vm_struct *vm) +static int memcg_charge_kernel_stack(struct vm_struct *vm_area) { int i; int ret; int nr_charged = 0; - BUG_ON(vm->nr_pages != THREAD_SIZE / PAGE_SIZE); + BUG_ON(vm_area->nr_pages != THREAD_SIZE / PAGE_SIZE); for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++) { - ret = memcg_kmem_charge_page(vm->pages[i], GFP_KERNEL, 0); + ret = memcg_kmem_charge_page(vm_area->pages[i], GFP_KERNEL, 0); if (ret) goto err; nr_charged++; @@ -273,38 +274,35 @@ static int memcg_charge_kernel_stack(str return 0; err: for (i = 0; i < nr_charged; i++) - memcg_kmem_uncharge_page(vm->pages[i], 0); + memcg_kmem_uncharge_page(vm_area->pages[i], 0); return ret; } static int alloc_thread_stack_node(struct task_struct *tsk, int node) { - struct vm_struct *vm; + struct vm_struct *vm_area; void *stack; int i; for (i = 0; i < NR_CACHED_STACKS; i++) { - struct vm_struct *s; - - s = this_cpu_xchg(cached_stacks[i], NULL); - - if (!s) + vm_area = this_cpu_xchg(cached_stacks[i], NULL); + if (!vm_area) continue; /* Reset stack metadata. */ - kasan_unpoison_range(s->addr, THREAD_SIZE); + kasan_unpoison_range(vm_area->addr, THREAD_SIZE); - stack = kasan_reset_tag(s->addr); + stack = kasan_reset_tag(vm_area->addr); /* Clear stale pointers from reused stack. */ memset(stack, 0, THREAD_SIZE); - if (memcg_charge_kernel_stack(s)) { - vfree(s->addr); + if (memcg_charge_kernel_stack(vm_area)) { + vfree(vm_area->addr); return -ENOMEM; } - tsk->stack_vm_area = s; + tsk->stack_vm_area = vm_area; tsk->stack = stack; return 0; } @@ -320,8 +318,8 @@ static int alloc_thread_stack_node(struc if (!stack) return -ENOMEM; - vm = find_vm_area(stack); - if (memcg_charge_kernel_stack(vm)) { + vm_area = find_vm_area(stack); + if (memcg_charge_kernel_stack(vm_area)) { vfree(stack); return -ENOMEM; } @@ -330,7 +328,7 @@ static int alloc_thread_stack_node(struc * free_thread_stack() can be called in interrupt context, * so cache the vm_struct. */ - tsk->stack_vm_area = vm; + tsk->stack_vm_area = vm_area; stack = kasan_reset_tag(stack); tsk->stack = stack; return 0; @@ -437,11 +435,11 @@ static struct kmem_cache *mm_cachep; static void account_kernel_stack(struct task_struct *tsk, int account) { if (IS_ENABLED(CONFIG_VMAP_STACK)) { - struct vm_struct *vm = task_stack_vm_area(tsk); + struct vm_struct *vm_area = task_stack_vm_area(tsk); int i; for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++) - mod_lruvec_page_state(vm->pages[i], NR_KERNEL_STACK_KB, + mod_lruvec_page_state(vm_area->pages[i], NR_KERNEL_STACK_KB, account * (PAGE_SIZE / 1024)); } else { void *stack = task_stack_page(tsk); @@ -457,12 +455,12 @@ void exit_task_stack_account(struct task account_kernel_stack(tsk, -1); if (IS_ENABLED(CONFIG_VMAP_STACK)) { - struct vm_struct *vm; + struct vm_struct *vm_area; int i; - vm = task_stack_vm_area(tsk); + vm_area = task_stack_vm_area(tsk); for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++) - memcg_kmem_uncharge_page(vm->pages[i], 0); + memcg_kmem_uncharge_page(vm_area->pages[i], 0); } } _ Patches currently in -mm which might be from pasha.tatashin@soleen.com are fork-clean-up-naming-of-vm_stack-vm_struct-variables-in-vmap-stacks-code.patch