From: "Mike Rapoport (IBM)" <rppt@xxxxxxxxxx>
Extend jitalloc parameters to accommodate more complex overrides of
module_alloc() by architectures.
This includes specification of a fallback range required by arm, arm64
and powerpc and support for allocation of KASAN shadow required by
arm64, s390 and x86.
The core implementation of jit_alloc() takes care of suppressing warnings
when the initial allocation fails but there is a fallback range defined.
Signed-off-by: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>
---
arch/arm/kernel/module.c | 32 ++++++++++----------
arch/arm64/kernel/module.c | 57 ++++++++++++++++--------------------
arch/powerpc/kernel/module.c | 46 +++++++++++++----------------
arch/s390/kernel/module.c | 31 ++++++++------------
arch/x86/kernel/module.c | 29 +++++++-----------
include/linux/jitalloc.h | 14 +++++++++
mm/jitalloc.c | 44 ++++++++++++++++++++++++----
7 files changed, 138 insertions(+), 115 deletions(-)
diff --git a/arch/arm/kernel/module.c b/arch/arm/kernel/module.c
index d59c36dc0494..83ccbf98164f 100644
--- a/arch/arm/kernel/module.c
+++ b/arch/arm/kernel/module.c
@@ -16,6 +16,7 @@
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/gfp.h>
+#include <linux/jitalloc.h>
#include <asm/sections.h>
#include <asm/smp_plat.h>
@@ -34,23 +35,22 @@
#endif
#ifdef CONFIG_MMU
-void *module_alloc(unsigned long size)
+static struct jit_alloc_params jit_alloc_params = {
+ .alignment = 1,
+ .text.start = MODULES_VADDR,
+ .text.end = MODULES_END,
+};
+
+struct jit_alloc_params *jit_alloc_arch_params(void)
{
- gfp_t gfp_mask = GFP_KERNEL;
- void *p;
-
- /* Silence the initial allocation */
- if (IS_ENABLED(CONFIG_ARM_MODULE_PLTS))
- gfp_mask |= __GFP_NOWARN;
-
- p = __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
- gfp_mask, PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
- __builtin_return_address(0));
- if (!IS_ENABLED(CONFIG_ARM_MODULE_PLTS) || p)
- return p;
- return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
- GFP_KERNEL, PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
- __builtin_return_address(0));
+ jit_alloc_params.text.pgprot = PAGE_KERNEL_EXEC;
+
+ if (IS_ENABLED(CONFIG_ARM_MODULE_PLTS)) {
+ jit_alloc_params.text.fallback_start = VMALLOC_START;
+ jit_alloc_params.text.fallback_end = VMALLOC_END;
+ }
+
+ return &jit_alloc_params;
}
#endif
diff --git a/arch/arm64/kernel/module.c b/arch/arm64/kernel/module.c
index 5af4975caeb5..ecf1f4030317 100644
--- a/arch/arm64/kernel/module.c
+++ b/arch/arm64/kernel/module.c
@@ -17,56 +17,49 @@
#include <linux/moduleloader.h>
#include <linux/scs.h>
#include <linux/vmalloc.h>
+#include <linux/jitalloc.h>
#include <asm/alternative.h>
#include <asm/insn.h>
#include <asm/scs.h>
#include <asm/sections.h>
-void *module_alloc(unsigned long size)
+static struct jit_alloc_params jit_alloc_params = {
+ .alignment = MODULE_ALIGN,
+ .flags = JIT_ALLOC_KASAN_SHADOW,
+};
+
+struct jit_alloc_params *jit_alloc_arch_params(void)
{
u64 module_alloc_end = module_alloc_base + MODULES_VSIZE;
- gfp_t gfp_mask = GFP_KERNEL;
- void *p;
-
- /* Silence the initial allocation */
- if (IS_ENABLED(CONFIG_ARM64_MODULE_PLTS))
- gfp_mask |= __GFP_NOWARN;
if (IS_ENABLED(CONFIG_KASAN_GENERIC) ||
IS_ENABLED(CONFIG_KASAN_SW_TAGS))
/* don't exceed the static module region - see below */
module_alloc_end = MODULES_END;
- p = __vmalloc_node_range(size, MODULE_ALIGN, module_alloc_base,
- module_alloc_end, gfp_mask, PAGE_KERNEL, VM_DEFER_KMEMLEAK,
- NUMA_NO_NODE, __builtin_return_address(0));
+ jit_alloc_params.text.pgprot = PAGE_KERNEL;
+ jit_alloc_params.text.start = module_alloc_base;
+ jit_alloc_params.text.end = module_alloc_end;
- if (!p && IS_ENABLED(CONFIG_ARM64_MODULE_PLTS) &&
+ /*
+ * KASAN without KASAN_VMALLOC can only deal with module
+ * allocations being served from the reserved module region,
+ * since the remainder of the vmalloc region is already
+ * backed by zero shadow pages, and punching holes into it
+ * is non-trivial. Since the module region is not randomized
+ * when KASAN is enabled without KASAN_VMALLOC, it is even
+ * less likely that the module region gets exhausted, so we
+ * can simply omit this fallback in that case.
+ */
+ if (IS_ENABLED(CONFIG_ARM64_MODULE_PLTS) &&
(IS_ENABLED(CONFIG_KASAN_VMALLOC) ||
(!IS_ENABLED(CONFIG_KASAN_GENERIC) &&
- !IS_ENABLED(CONFIG_KASAN_SW_TAGS))))
- /*
- * KASAN without KASAN_VMALLOC can only deal with module
- * allocations being served from the reserved module region,
- * since the remainder of the vmalloc region is already
- * backed by zero shadow pages, and punching holes into it
- * is non-trivial. Since the module region is not randomized
- * when KASAN is enabled without KASAN_VMALLOC, it is even
- * less likely that the module region gets exhausted, so we
- * can simply omit this fallback in that case.
- */
- p = __vmalloc_node_range(size, MODULE_ALIGN, module_alloc_base,
- module_alloc_base + SZ_2G, GFP_KERNEL,
- PAGE_KERNEL, 0, NUMA_NO_NODE,
- __builtin_return_address(0));
-
- if (p && (kasan_alloc_module_shadow(p, size, gfp_mask) < 0)) {
- vfree(p);
- return NULL;
+ !IS_ENABLED(CONFIG_KASAN_SW_TAGS)))) {
+ jit_alloc_params.text.fallback_start = module_alloc_base;
+ jit_alloc_params.text.fallback_end = module_alloc_base + SZ_2G;
}
- /* Memory is intended to be executable, reset the pointer tag. */
- return kasan_reset_tag(p);
+ return &jit_alloc_params;
}
enum aarch64_reloc_op {
diff --git a/arch/powerpc/kernel/module.c b/arch/powerpc/kernel/module.c
index f6d6ae0a1692..83bdedc7eba0 100644
--- a/arch/powerpc/kernel/module.c
+++ b/arch/powerpc/kernel/module.c
@@ -12,6 +12,7 @@
#include <linux/bug.h>
#include <asm/module.h>
#include <linux/uaccess.h>
+#include <linux/jitalloc.h>
#include <asm/firmware.h>
#include <linux/sort.h>
#include <asm/setup.h>
@@ -89,39 +90,32 @@ int module_finalize(const Elf_Ehdr *hdr,
return 0;
}
-static __always_inline void *
-__module_alloc(unsigned long size, unsigned long start, unsigned long end, bool nowarn)
-{
- pgprot_t prot = strict_module_rwx_enabled() ? PAGE_KERNEL : PAGE_KERNEL_EXEC;
- gfp_t gfp = GFP_KERNEL | (nowarn ? __GFP_NOWARN : 0);
-
- /*
- * Don't do huge page allocations for modules yet until more testing
- * is done. STRICT_MODULE_RWX may require extra work to support this
- * too.
- */
- return __vmalloc_node_range(size, 1, start, end, gfp, prot,
- VM_FLUSH_RESET_PERMS,
- NUMA_NO_NODE, __builtin_return_address(0));
-}
+static struct jit_alloc_params jit_alloc_params = {
+ .alignment = 1,
+};
-void *module_alloc(unsigned long size)
+struct jit_alloc_params *jit_alloc_arch_params(void)
{
#ifdef MODULES_VADDR
+ pgprot_t prot = strict_module_rwx_enabled() ? PAGE_KERNEL : PAGE_KERNEL_EXEC;
unsigned long limit = (unsigned long)_etext - SZ_32M;
- void *ptr = NULL;
- BUILD_BUG_ON(TASK_SIZE > MODULES_VADDR);
+ jit_alloc_params.text.pgprot = prot;
/* First try within 32M limit from _etext to avoid branch trampolines */
- if (MODULES_VADDR < PAGE_OFFSET && MODULES_END > limit)
- ptr = __module_alloc(size, limit, MODULES_END, true);
-
- if (!ptr)
- ptr = __module_alloc(size, MODULES_VADDR, MODULES_END, false);
-
- return ptr;
+ if (MODULES_VADDR < PAGE_OFFSET && MODULES_END > limit) {
+ jit_alloc_params.text.start = limit;
+ jit_alloc_params.text.end = MODULES_END;
+ jit_alloc_params.text.fallback_start = MODULES_VADDR;
+ jit_alloc_params.text.fallback_end = MODULES_END;
+ } else {
+ jit_alloc_params.text.start = MODULES_VADDR;
+ jit_alloc_params.text.end = MODULES_END;
+ }
#else
- return __module_alloc(size, VMALLOC_START, VMALLOC_END, false);
+ jit_alloc_params.text.start = VMALLOC_START;
+ jit_alloc_params.text.end = VMALLOC_END;
#endif
+
+ return &jit_alloc_params;
}
diff --git a/arch/s390/kernel/module.c b/arch/s390/kernel/module.c
index d4844cfe3d7e..0986a1a1b261 100644
--- a/arch/s390/kernel/module.c
+++ b/arch/s390/kernel/module.c
@@ -55,23 +55,18 @@ static unsigned long get_module_load_offset(void)
return module_load_offset;
}
-void *module_alloc(unsigned long size)
+static struct jit_alloc_params jit_alloc_params = {
+ .alignment = MODULE_ALIGN,
+ .flags = JIT_ALLOC_KASAN_SHADOW,
+ .text.pgprot = PAGE_KERNEL,
+};
+
+struct jit_alloc_params *jit_alloc_arch_params(void)
{
- gfp_t gfp_mask = GFP_KERNEL;
- void *p;
-
- if (PAGE_ALIGN(size) > MODULES_LEN)
- return NULL;
- p = __vmalloc_node_range(size, MODULE_ALIGN,
- MODULES_VADDR + get_module_load_offset(),
- MODULES_END, gfp_mask, PAGE_KERNEL,
- VM_FLUSH_RESET_PERMS | VM_DEFER_KMEMLEAK,
- NUMA_NO_NODE, __builtin_return_address(0));
- if (p && (kasan_alloc_module_shadow(p, size, gfp_mask) < 0)) {
- vfree(p);
- return NULL;
- }
- return p;
+ jit_alloc_params.text.start = MODULES_VADDR + get_module_load_offset();
+ jit_alloc_params.text.end = MODULES_END;
+
+ return &jit_alloc_params;
}
#ifdef CONFIG_FUNCTION_TRACER
@@ -130,7 +125,7 @@ static void check_rela(Elf_Rela *rela, struct module *me)
case R_390_GLOB_DAT:
case R_390_JMP_SLOT:
case R_390_RELATIVE:
- /* Only needed if we want to support loading of
+ /* Only needed if we want to support loading of
modules linked with -shared. */
break;
}
@@ -442,7 +437,7 @@ static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab,
case R_390_GLOB_DAT: /* Create GOT entry. */
case R_390_JMP_SLOT: /* Create PLT entry. */
case R_390_RELATIVE: /* Adjust by program base. */
- /* Only needed if we want to support loading of
+ /* Only needed if we want to support loading of
modules linked with -shared. */
return -ENOEXEC;
default:
diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
index b05f62ee2344..cce84b61a036 100644
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -19,6 +19,7 @@
#include <linux/jump_label.h>
#include <linux/random.h>
#include <linux/memory.h>
+#include <linux/jitalloc.h>
#include <asm/text-patching.h>
#include <asm/page.h>
@@ -65,26 +66,18 @@ static unsigned long int get_module_load_offset(void)
}
#endif
-void *module_alloc(unsigned long size)
-{
- gfp_t gfp_mask = GFP_KERNEL;
- void *p;
-
- if (PAGE_ALIGN(size) > MODULES_LEN)
- return NULL;
-
- p = __vmalloc_node_range(size, MODULE_ALIGN,
- MODULES_VADDR + get_module_load_offset(),
- MODULES_END, gfp_mask, PAGE_KERNEL,
- VM_FLUSH_RESET_PERMS | VM_DEFER_KMEMLEAK,
- NUMA_NO_NODE, __builtin_return_address(0));
+static struct jit_alloc_params jit_alloc_params = {
+ .alignment = MODULE_ALIGN,
+ .flags = JIT_ALLOC_KASAN_SHADOW,
+};
- if (p && (kasan_alloc_module_shadow(p, size, gfp_mask) < 0)) {
- vfree(p);
- return NULL;
- }
+struct jit_alloc_params *jit_alloc_arch_params(void)
+{
+ jit_alloc_params.text.pgprot = PAGE_KERNEL;
+ jit_alloc_params.text.start = MODULES_VADDR + get_module_load_offset();
+ jit_alloc_params.text.end = MODULES_END;
- return p;
+ return &jit_alloc_params;
}
#ifdef CONFIG_X86_32
diff --git a/include/linux/jitalloc.h b/include/linux/jitalloc.h
index 34fddef23dea..34ee57795a18 100644
--- a/include/linux/jitalloc.h
+++ b/include/linux/jitalloc.h
@@ -4,26 +4,40 @@
#include <linux/types.h>
+/**
+ * enum jit_alloc_flags - options for executable memory allocations
+ * @JIT_ALLOC_KASAN_SHADOW: allocate kasan shadow
+ */
+enum jit_alloc_flags {
+ JIT_ALLOC_KASAN_SHADOW = (1 << 0),
+};
+
/**
* struct jit_address_space - address space definition for code and
* related data allocations
* @pgprot: permisssions for memory in this address space
* @start: address space start
* @end: address space end (inclusive)
+ * @fallback_start: start of the range for fallback allocations
+ * @fallback_end: end of the range for fallback allocations (inclusive)
*/
struct jit_address_space {
pgprot_t pgprot;
unsigned long start;
unsigned long end;
+ unsigned long fallback_start;
+ unsigned long fallback_end;
};
/**
* struct jit_alloc_params - architecure parameters for code allocations
* @text: address space range for text allocations
+ * @flags: options for executable memory allocations
* @alignment: alignment required for text allocations
*/
struct jit_alloc_params {
struct jit_address_space text;
+ enum jit_alloc_flags flags;
unsigned int alignment;
};
diff --git a/mm/jitalloc.c b/mm/jitalloc.c
index 3e63eeb8bf4b..4e10af7803f7 100644
--- a/mm/jitalloc.c
+++ b/mm/jitalloc.c
@@ -8,14 +8,44 @@
static struct jit_alloc_params jit_alloc_params;
static void *jit_alloc(size_t len, unsigned int alignment, pgprot_t pgprot,
- unsigned long start, unsigned long end)
+ unsigned long start, unsigned long end,
+ unsigned long fallback_start, unsigned long fallback_end,
+ bool kasan)
{
+ unsigned long vm_flags = VM_FLUSH_RESET_PERMS;
+ bool fallback = !!fallback_start;
+ gfp_t gfp_flags = GFP_KERNEL;
+ void *p;
+
if (PAGE_ALIGN(len) > (end - start))
return NULL;
- return __vmalloc_node_range(len, alignment, start, end, GFP_KERNEL,
- pgprot, VM_FLUSH_RESET_PERMS,
- NUMA_NO_NODE, __builtin_return_address(0));
+ if (kasan)
+ vm_flags |= VM_DEFER_KMEMLEAK;
+
+ if (fallback)
+ gfp_flags |= __GFP_NOWARN;
+
+ p = __vmalloc_node_range(len, alignment, start, end, gfp_flags,
+ pgprot, vm_flags, NUMA_NO_NODE,
+ __builtin_return_address(0));
+
+ if (!p && fallback) {
+ start = fallback_start;
+ end = fallback_end;
+ gfp_flags = GFP_KERNEL;
+
+ p = __vmalloc_node_range(len, alignment, start, end, gfp_flags,
+ pgprot, vm_flags, NUMA_NO_NODE,
+ __builtin_return_address(0));
+ }
+
+ if (p && kasan && (kasan_alloc_module_shadow(p, len, GFP_KERNEL) < 0)) {
+ vfree(p);
+ return NULL;
+ }
+
+ return kasan_reset_tag(p);
}
void jit_free(void *buf)
@@ -35,8 +65,12 @@ void *jit_text_alloc(size_t len)
pgprot_t pgprot = jit_alloc_params.text.pgprot;
unsigned long start = jit_alloc_params.text.start;
unsigned long end = jit_alloc_params.text.end;
+ unsigned long fallback_start = jit_alloc_params.text.fallback_start;
+ unsigned long fallback_end = jit_alloc_params.text.fallback_end;
+ bool kasan = jit_alloc_params.flags & JIT_ALLOC_KASAN_SHADOW;
- return jit_alloc(len, align, pgprot, start, end);
+ return jit_alloc(len, align, pgprot, start, end,
+ fallback_start, fallback_end, kasan);
}
return module_alloc(len);
--
2.35.1
