arm64: entry: Allow the trampoline text to occupy multiple pages

commit a9c406e6462ff14956d690de7bbe5131a5677dc9 upstream.

Adding a second set of vectors to .entry.tramp.text will make it
larger than a single 4K page.

Allow the trampoline text to occupy up to three pages by adding two
more fixmap slots. Previous changes to tramp_valias allowed it to reach
beyond a single page.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/arm64/include/asm/fixmap.h b/arch/arm64/include/asm/fixmap.h
index feee38303afe4f15c21aa8f97d82b761552730a7..4ffe0d698fa726c35da8ad7e71cdb98837dccc84 100644 (file)
--- a/arch/arm64/include/asm/fixmap.h
+++ b/arch/arm64/include/asm/fixmap.h
@@ -53,9 +53,11 @@ enum fixed_addresses {
        FIX_TEXT_POKE0,
 
 #ifdef CONFIG_UNMAP_KERNEL_AT_EL0
-       FIX_ENTRY_TRAMP_TEXT,
+       FIX_ENTRY_TRAMP_TEXT3,
+       FIX_ENTRY_TRAMP_TEXT2,
+       FIX_ENTRY_TRAMP_TEXT1,
        FIX_ENTRY_TRAMP_DATA,
-#define TRAMP_VALIAS           (__fix_to_virt(FIX_ENTRY_TRAMP_TEXT))
+#define TRAMP_VALIAS           (__fix_to_virt(FIX_ENTRY_TRAMP_TEXT1))
 #endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */
        __end_of_permanent_fixed_addresses,
 

diff --git a/arch/arm64/include/asm/sections.h b/arch/arm64/include/asm/sections.h
index 4e7e7067afdb048d464d9287f42f16ebc26aeb7b..09ebd37d5aa3c183e358cc1bf1f89eb16f767d5c 100644 (file)
--- a/arch/arm64/include/asm/sections.h
+++ b/arch/arm64/include/asm/sections.h
@@ -26,5 +26,11 @@ extern char __hyp_text_start[], __hyp_text_end[];
 extern char __idmap_text_start[], __idmap_text_end[];
 extern char __irqentry_text_start[], __irqentry_text_end[];
 extern char __mmuoff_data_start[], __mmuoff_data_end[];
+extern char __entry_tramp_text_start[], __entry_tramp_text_end[];
+
+static inline size_t entry_tramp_text_size(void)
+{
+       return __entry_tramp_text_end - __entry_tramp_text_start;
+}
 
 #endif /* __ASM_SECTIONS_H */

diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 6e1d02d87d4593ec085a7e3f6830dc8e07bf396c..b9a757216a806b469787ef169ec207ba8dd7deea 100644 (file)
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -917,7 +917,7 @@ __ni_sys_trace:
        .endm
 
        .macro tramp_data_page  dst
-       adr     \dst, .entry.tramp.text
+       adr_l   \dst, .entry.tramp.text
        sub     \dst, \dst, PAGE_SIZE
        .endm
 

diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S
index fa3ffad50a61cbf5ebb6c7d396446741ce5f0aa4..17fc1671b99004f73b4487db589e44a2c318f73e 100644 (file)
--- a/arch/arm64/kernel/vmlinux.lds.S
+++ b/arch/arm64/kernel/vmlinux.lds.S
@@ -261,7 +261,7 @@ ASSERT(__hibernate_exit_text_end - (__hibernate_exit_text_start & ~(SZ_4K - 1))
        <= SZ_4K, "Hibernate exit text too big or misaligned")
 #endif
 #ifdef CONFIG_UNMAP_KERNEL_AT_EL0
-ASSERT((__entry_tramp_text_end - __entry_tramp_text_start) == PAGE_SIZE,
+ASSERT((__entry_tramp_text_end - __entry_tramp_text_start) <= 3*PAGE_SIZE,
        "Entry trampoline text too big")
 #endif
 /*

diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 60be5bc0984ad3a41993c439bb105e7840cd16aa..36bd50091c4bbc7fb2bd08bb28fb1008300a59e8 100644 (file)
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -438,6 +438,7 @@ static void __init map_kernel_segment(pgd_t *pgd, void *va_start, void *va_end,
 #ifdef CONFIG_UNMAP_KERNEL_AT_EL0
 static int __init map_entry_trampoline(void)
 {
+       int i;
        extern char __entry_tramp_text_start[];
 
        pgprot_t prot = rodata_enabled ? PAGE_KERNEL_ROX : PAGE_KERNEL_EXEC;
@@ -448,11 +449,15 @@ static int __init map_entry_trampoline(void)
 
        /* Map only the text into the trampoline page table */
        memset(tramp_pg_dir, 0, PGD_SIZE);
-       __create_pgd_mapping(tramp_pg_dir, pa_start, TRAMP_VALIAS, PAGE_SIZE,
-                            prot, pgd_pgtable_alloc, 0);
+       __create_pgd_mapping(tramp_pg_dir, pa_start, TRAMP_VALIAS,
+                            entry_tramp_text_size(), prot, pgd_pgtable_alloc,
+                            0);
 
        /* Map both the text and data into the kernel page table */
-       __set_fixmap(FIX_ENTRY_TRAMP_TEXT, pa_start, prot);
+       for (i = 0; i < DIV_ROUND_UP(entry_tramp_text_size(), PAGE_SIZE); i++)
+               __set_fixmap(FIX_ENTRY_TRAMP_TEXT1 - i,
+                            pa_start + i * PAGE_SIZE, prot);
+
        if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
                extern char __entry_tramp_data_start[];