From: "Thomas Weißschuh" <linux@weissschuh.net>
To: Richard Weinberger <richard@nod.at>,
Anton Ivanov <anton.ivanov@cambridgegreys.com>,
Johannes Berg <johannes@sipsolutions.net>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
Kees Cook <kees@kernel.org>
Cc: linux-um@lists.infradead.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, "Thomas Weißschuh" <linux@weissschuh.net>
Subject: [PATCH 06/10] um: Remove fixaddr_user_init()
Date: Tue, 28 Oct 2025 10:15:41 +0100 [thread overview]
Message-ID: <20251028-uml-remove-32bit-pseudo-vdso-v1-6-e930063eff5f@weissschuh.net> (raw)
In-Reply-To: <20251028-uml-remove-32bit-pseudo-vdso-v1-0-e930063eff5f@weissschuh.net>
With the removal of the vDSO passthrough from the host,
FIXADDR_USER_START is always 0 and fixaddr_user_init() is dead code.
Remove it.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
arch/um/kernel/mem.c | 107 ---------------------------------------------------
1 file changed, 107 deletions(-)
diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
index dc938715ec9d..39c4a7e21c6f 100644
--- a/arch/um/kernel/mem.c
+++ b/arch/um/kernel/mem.c
@@ -84,109 +84,6 @@ void __init mem_init(void)
kmalloc_ok = 1;
}
-#if IS_ENABLED(CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA)
-/*
- * Create a page table and place a pointer to it in a middle page
- * directory entry.
- */
-static void __init one_page_table_init(pmd_t *pmd)
-{
- if (pmd_none(*pmd)) {
- pte_t *pte = (pte_t *) memblock_alloc_low(PAGE_SIZE,
- PAGE_SIZE);
- if (!pte)
- panic("%s: Failed to allocate %lu bytes align=%lx\n",
- __func__, PAGE_SIZE, PAGE_SIZE);
-
- set_pmd(pmd, __pmd(_KERNPG_TABLE +
- (unsigned long) __pa(pte)));
- BUG_ON(pte != pte_offset_kernel(pmd, 0));
- }
-}
-
-static void __init one_md_table_init(pud_t *pud)
-{
-#if CONFIG_PGTABLE_LEVELS > 2
- pmd_t *pmd_table = (pmd_t *) memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
- if (!pmd_table)
- panic("%s: Failed to allocate %lu bytes align=%lx\n",
- __func__, PAGE_SIZE, PAGE_SIZE);
-
- set_pud(pud, __pud(_KERNPG_TABLE + (unsigned long) __pa(pmd_table)));
- BUG_ON(pmd_table != pmd_offset(pud, 0));
-#endif
-}
-
-static void __init one_ud_table_init(p4d_t *p4d)
-{
-#if CONFIG_PGTABLE_LEVELS > 3
- pud_t *pud_table = (pud_t *) memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
- if (!pud_table)
- panic("%s: Failed to allocate %lu bytes align=%lx\n",
- __func__, PAGE_SIZE, PAGE_SIZE);
-
- set_p4d(p4d, __p4d(_KERNPG_TABLE + (unsigned long) __pa(pud_table)));
- BUG_ON(pud_table != pud_offset(p4d, 0));
-#endif
-}
-
-static void __init fixrange_init(unsigned long start, unsigned long end,
- pgd_t *pgd_base)
-{
- pgd_t *pgd;
- p4d_t *p4d;
- pud_t *pud;
- pmd_t *pmd;
- int i, j;
- unsigned long vaddr;
-
- vaddr = start;
- i = pgd_index(vaddr);
- j = pmd_index(vaddr);
- pgd = pgd_base + i;
-
- for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
- p4d = p4d_offset(pgd, vaddr);
- if (p4d_none(*p4d))
- one_ud_table_init(p4d);
- pud = pud_offset(p4d, vaddr);
- if (pud_none(*pud))
- one_md_table_init(pud);
- pmd = pmd_offset(pud, vaddr);
- for (; (j < PTRS_PER_PMD) && (vaddr < end); pmd++, j++) {
- one_page_table_init(pmd);
- vaddr += PMD_SIZE;
- }
- j = 0;
- }
-}
-
-static void __init fixaddr_user_init( void)
-{
- long size = FIXADDR_USER_END - FIXADDR_USER_START;
- pte_t *pte;
- phys_t p;
- unsigned long v, vaddr = FIXADDR_USER_START;
-
- if (!size)
- return;
-
- fixrange_init( FIXADDR_USER_START, FIXADDR_USER_END, swapper_pg_dir);
- v = (unsigned long) memblock_alloc_low(size, PAGE_SIZE);
- if (!v)
- panic("%s: Failed to allocate %lu bytes align=%lx\n",
- __func__, size, PAGE_SIZE);
-
- memcpy((void *) v , (void *) FIXADDR_USER_START, size);
- p = __pa(v);
- for ( ; size > 0; size -= PAGE_SIZE, vaddr += PAGE_SIZE,
- p += PAGE_SIZE) {
- pte = virt_to_kpte(vaddr);
- pte_set_val(*pte, p, PAGE_READONLY);
- }
-}
-#endif
-
void __init paging_init(void)
{
unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 };
@@ -199,10 +96,6 @@ void __init paging_init(void)
max_zone_pfn[ZONE_NORMAL] = high_physmem >> PAGE_SHIFT;
free_area_init(max_zone_pfn);
-
-#if IS_ENABLED(CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA)
- fixaddr_user_init();
-#endif
}
/*
--
2.51.1.dirty
next prev parent reply other threads:[~2025-10-28 9:17 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-28 9:15 [PATCH 00/10] um: remove vDSO passthrough on 32bit x86 Thomas Weißschuh
2025-10-28 9:15 ` [PATCH 01/10] um: Split out default elf_aux_platform Thomas Weißschuh
2025-10-28 9:15 ` [PATCH 02/10] x86/um: Move ELF_PLATFORM fallback to x86-specific code Thomas Weißschuh
2025-10-28 9:15 ` [PATCH 03/10] um: Split out default elf_aux_hwcap Thomas Weißschuh
2025-10-28 9:15 ` [PATCH 04/10] x86/um: Do not inherit vDSO from host Thomas Weißschuh
2025-10-28 9:15 ` [PATCH 05/10] x86/um: Drop gate area handling Thomas Weißschuh
2025-10-28 9:15 ` Thomas Weißschuh [this message]
2025-10-28 9:15 ` [PATCH 07/10] um: Remove redundant range check from __access_ok_vsyscall() Thomas Weißschuh
2025-10-28 9:15 ` [PATCH 08/10] um: Remove __access_ok_vsyscall() Thomas Weißschuh
2025-10-28 9:15 ` [PATCH 09/10] x86/um: Remove FIXADDR_USER_START and FIXADDR_USE_END Thomas Weißschuh
2025-10-28 9:15 ` [PATCH 10/10] um: Always set up AT_HWCAP and AT_PLATFORM Thomas Weißschuh
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