[PATCHv3 3/8] powerpc/vdso: separate common code in vdso_common
Dmitry Safonov
dsafonov at virtuozzo.com
Fri Oct 28 04:09:43 AEDT 2016
Impact: cleanup
There are common functions for handeling 32-bit and 64-bit vDSO ELF
files: find_section{32,64}, find_symbol{32,64}, find_function{32,64},
vdso_do_func_patch{32,64}, vdso_do_find_sections{32,64},
vdso_fixup_datapag{32,64}, vdso_fixup_features{32,64}, vdso_setup{32,64}
which all do the same work with the only difference is using structures
for 32 or 64 bit ELF. Let's combine them into common code, reducing
copy'n'paste code.
Small changes:
I also switched usage of printk(KERNEL_<LEVEL>,...) on pr_<level>(...)
and used pr_fmt() macro for "vDSO{32,64}: " prefix.
Cc: Benjamin Herrenschmidt <benh at kernel.crashing.org>
Cc: Paul Mackerras <paulus at samba.org>
Cc: Michael Ellerman <mpe at ellerman.id.au>
Cc: Andy Lutomirski <luto at amacapital.net>
Cc: Oleg Nesterov <oleg at redhat.com>
Cc: linuxppc-dev at lists.ozlabs.org
Cc: linux-mm at kvack.org
Signed-off-by: Dmitry Safonov <dsafonov at virtuozzo.com>
---
arch/powerpc/kernel/vdso.c | 352 ++------------------------------------
arch/powerpc/kernel/vdso_common.c | 221 ++++++++++++++++++++++++
2 files changed, 234 insertions(+), 339 deletions(-)
create mode 100644 arch/powerpc/kernel/vdso_common.c
diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
index 278b9aa25a1c..8010a0d82049 100644
--- a/arch/powerpc/kernel/vdso.c
+++ b/arch/powerpc/kernel/vdso.c
@@ -51,13 +51,13 @@
#define VDSO_ALIGNMENT (1 << 16)
static unsigned int vdso32_pages;
-static void *vdso32_kbase;
static struct page **vdso32_pagelist;
unsigned long vdso32_sigtramp;
unsigned long vdso32_rt_sigtramp;
#ifdef CONFIG_VDSO32
extern char vdso32_start, vdso32_end;
+static void *vdso32_kbase;
#endif
#ifdef CONFIG_PPC64
@@ -246,250 +246,16 @@ const char *arch_vma_name(struct vm_area_struct *vma)
return NULL;
}
-
-
#ifdef CONFIG_VDSO32
-static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
- unsigned long *size)
-{
- Elf32_Shdr *sechdrs;
- unsigned int i;
- char *secnames;
-
- /* Grab section headers and strings so we can tell who is who */
- sechdrs = (void *)ehdr + ehdr->e_shoff;
- secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
-
- /* Find the section they want */
- for (i = 1; i < ehdr->e_shnum; i++) {
- if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
- if (size)
- *size = sechdrs[i].sh_size;
- return (void *)ehdr + sechdrs[i].sh_offset;
- }
- }
- *size = 0;
- return NULL;
-}
-
-static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib,
- const char *symname)
-{
- unsigned int i;
- char name[MAX_SYMNAME], *c;
-
- for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) {
- if (lib->dynsym[i].st_name == 0)
- continue;
- strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
- MAX_SYMNAME);
- c = strchr(name, '@');
- if (c)
- *c = 0;
- if (strcmp(symname, name) == 0)
- return &lib->dynsym[i];
- }
- return NULL;
-}
-
-/* Note that we assume the section is .text and the symbol is relative to
- * the library base
- */
-static unsigned long __init find_function32(struct lib32_elfinfo *lib,
- const char *symname)
-{
- Elf32_Sym *sym = find_symbol32(lib, symname);
-
- if (sym == NULL) {
- printk(KERN_WARNING "vDSO32: function %s not found !\n",
- symname);
- return 0;
- }
- return sym->st_value - VDSO32_LBASE;
-}
-
-static int __init vdso_do_func_patch32(struct lib32_elfinfo *v32,
- const char *orig, const char *fix)
-{
- Elf32_Sym *sym32_gen, *sym32_fix;
-
- sym32_gen = find_symbol32(v32, orig);
- if (sym32_gen == NULL) {
- printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", orig);
- return -1;
- }
- if (fix == NULL) {
- sym32_gen->st_name = 0;
- return 0;
- }
- sym32_fix = find_symbol32(v32, fix);
- if (sym32_fix == NULL) {
- printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", fix);
- return -1;
- }
- sym32_gen->st_value = sym32_fix->st_value;
- sym32_gen->st_size = sym32_fix->st_size;
- sym32_gen->st_info = sym32_fix->st_info;
- sym32_gen->st_other = sym32_fix->st_other;
- sym32_gen->st_shndx = sym32_fix->st_shndx;
-
- return 0;
-}
-#else /* !CONFIG_VDSO32 */
-static unsigned long __init find_function32(struct lib32_elfinfo *lib,
- const char *symname)
-{
- return 0;
-}
-
-static int __init vdso_do_func_patch32(struct lib32_elfinfo *v32,
- const char *orig, const char *fix)
-{
- return 0;
-}
+#include "vdso_common.c"
#endif /* CONFIG_VDSO32 */
-
#ifdef CONFIG_PPC64
-
-static void * __init find_section64(Elf64_Ehdr *ehdr, const char *secname,
- unsigned long *size)
-{
- Elf64_Shdr *sechdrs;
- unsigned int i;
- char *secnames;
-
- /* Grab section headers and strings so we can tell who is who */
- sechdrs = (void *)ehdr + ehdr->e_shoff;
- secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
-
- /* Find the section they want */
- for (i = 1; i < ehdr->e_shnum; i++) {
- if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
- if (size)
- *size = sechdrs[i].sh_size;
- return (void *)ehdr + sechdrs[i].sh_offset;
- }
- }
- if (size)
- *size = 0;
- return NULL;
-}
-
-static Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib,
- const char *symname)
-{
- unsigned int i;
- char name[MAX_SYMNAME], *c;
-
- for (i = 0; i < (lib->dynsymsize / sizeof(Elf64_Sym)); i++) {
- if (lib->dynsym[i].st_name == 0)
- continue;
- strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
- MAX_SYMNAME);
- c = strchr(name, '@');
- if (c)
- *c = 0;
- if (strcmp(symname, name) == 0)
- return &lib->dynsym[i];
- }
- return NULL;
-}
-
-/* Note that we assume the section is .text and the symbol is relative to
- * the library base
- */
-static unsigned long __init find_function64(struct lib64_elfinfo *lib,
- const char *symname)
-{
- Elf64_Sym *sym = find_symbol64(lib, symname);
-
- if (sym == NULL) {
- printk(KERN_WARNING "vDSO64: function %s not found !\n",
- symname);
- return 0;
- }
-#ifdef VDS64_HAS_DESCRIPTORS
- return *((u64 *)(vdso64_kbase + sym->st_value - VDSO64_LBASE)) -
- VDSO64_LBASE;
-#else
- return sym->st_value - VDSO64_LBASE;
-#endif
-}
-
-static int __init vdso_do_func_patch64(struct lib64_elfinfo *v64,
- const char *orig, const char *fix)
-{
- Elf64_Sym *sym64_gen, *sym64_fix;
-
- sym64_gen = find_symbol64(v64, orig);
- if (sym64_gen == NULL) {
- printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", orig);
- return -1;
- }
- if (fix == NULL) {
- sym64_gen->st_name = 0;
- return 0;
- }
- sym64_fix = find_symbol64(v64, fix);
- if (sym64_fix == NULL) {
- printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", fix);
- return -1;
- }
- sym64_gen->st_value = sym64_fix->st_value;
- sym64_gen->st_size = sym64_fix->st_size;
- sym64_gen->st_info = sym64_fix->st_info;
- sym64_gen->st_other = sym64_fix->st_other;
- sym64_gen->st_shndx = sym64_fix->st_shndx;
-
- return 0;
-}
-
+#define BITS 64
+#include "vdso_common.c"
#endif /* CONFIG_PPC64 */
-static __init int vdso_do_find_sections(struct lib32_elfinfo *v32,
- struct lib64_elfinfo *v64)
-{
- void *sect;
-
- /*
- * Locate symbol tables & text section
- */
-
-#ifdef CONFIG_VDSO32
- v32->dynsym = find_section32(v32->hdr, ".dynsym", &v32->dynsymsize);
- v32->dynstr = find_section32(v32->hdr, ".dynstr", NULL);
- if (v32->dynsym == NULL || v32->dynstr == NULL) {
- printk(KERN_ERR "vDSO32: required symbol section not found\n");
- return -1;
- }
- sect = find_section32(v32->hdr, ".text", NULL);
- if (sect == NULL) {
- printk(KERN_ERR "vDSO32: the .text section was not found\n");
- return -1;
- }
- v32->text = sect - vdso32_kbase;
-#endif
-
-#ifdef CONFIG_PPC64
- v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize);
- v64->dynstr = find_section64(v64->hdr, ".dynstr", NULL);
- if (v64->dynsym == NULL || v64->dynstr == NULL) {
- printk(KERN_ERR "vDSO64: required symbol section not found\n");
- return -1;
- }
- sect = find_section64(v64->hdr, ".text", NULL);
- if (sect == NULL) {
- printk(KERN_ERR "vDSO64: the .text section was not found\n");
- return -1;
- }
- v64->text = sect - vdso64_kbase;
-#endif /* CONFIG_PPC64 */
-
- return 0;
-}
-
static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
struct lib64_elfinfo *v64)
{
@@ -500,99 +266,10 @@ static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
#ifdef CONFIG_PPC64
vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
#endif
+#ifdef CONFIG_VDSO32
vdso32_sigtramp = find_function32(v32, "__kernel_sigtramp32");
vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32");
-}
-
-static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32,
- struct lib64_elfinfo *v64)
-{
-#ifdef CONFIG_VDSO32
- Elf32_Sym *sym32;
-#endif
-#ifdef CONFIG_PPC64
- Elf64_Sym *sym64;
-
- sym64 = find_symbol64(v64, "__kernel_datapage_offset");
- if (sym64 == NULL) {
- printk(KERN_ERR "vDSO64: Can't find symbol "
- "__kernel_datapage_offset !\n");
- return -1;
- }
- *((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) =
- (vdso64_pages << PAGE_SHIFT) -
- (sym64->st_value - VDSO64_LBASE);
-#endif /* CONFIG_PPC64 */
-
-#ifdef CONFIG_VDSO32
- sym32 = find_symbol32(v32, "__kernel_datapage_offset");
- if (sym32 == NULL) {
- printk(KERN_ERR "vDSO32: Can't find symbol "
- "__kernel_datapage_offset !\n");
- return -1;
- }
- *((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) =
- (vdso32_pages << PAGE_SHIFT) -
- (sym32->st_value - VDSO32_LBASE);
#endif
-
- return 0;
-}
-
-
-static __init int vdso_fixup_features(struct lib32_elfinfo *v32,
- struct lib64_elfinfo *v64)
-{
- unsigned long size;
- void *start;
-
-#ifdef CONFIG_PPC64
- start = find_section64(v64->hdr, "__ftr_fixup", &size);
- if (start)
- do_feature_fixups(cur_cpu_spec->cpu_features,
- start, start + size);
-
- start = find_section64(v64->hdr, "__mmu_ftr_fixup", &size);
- if (start)
- do_feature_fixups(cur_cpu_spec->mmu_features,
- start, start + size);
-
- start = find_section64(v64->hdr, "__fw_ftr_fixup", &size);
- if (start)
- do_feature_fixups(powerpc_firmware_features,
- start, start + size);
-
- start = find_section64(v64->hdr, "__lwsync_fixup", &size);
- if (start)
- do_lwsync_fixups(cur_cpu_spec->cpu_features,
- start, start + size);
-#endif /* CONFIG_PPC64 */
-
-#ifdef CONFIG_VDSO32
- start = find_section32(v32->hdr, "__ftr_fixup", &size);
- if (start)
- do_feature_fixups(cur_cpu_spec->cpu_features,
- start, start + size);
-
- start = find_section32(v32->hdr, "__mmu_ftr_fixup", &size);
- if (start)
- do_feature_fixups(cur_cpu_spec->mmu_features,
- start, start + size);
-
-#ifdef CONFIG_PPC64
- start = find_section32(v32->hdr, "__fw_ftr_fixup", &size);
- if (start)
- do_feature_fixups(powerpc_firmware_features,
- start, start + size);
-#endif /* CONFIG_PPC64 */
-
- start = find_section32(v32->hdr, "__lwsync_fixup", &size);
- if (start)
- do_lwsync_fixups(cur_cpu_spec->cpu_features,
- start, start + size);
-#endif
-
- return 0;
}
static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
@@ -616,7 +293,9 @@ static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
* It would be easy to do, but doesn't seem to be necessary,
* patching the OPD symbol is enough.
*/
+#ifdef CONFIG_VDSO32
vdso_do_func_patch32(v32, patch->gen_name, patch->fix_name);
+#endif
#ifdef CONFIG_PPC64
vdso_do_func_patch64(v64, patch->gen_name, patch->fix_name);
#endif /* CONFIG_PPC64 */
@@ -625,24 +304,19 @@ static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
return 0;
}
-
static __init int vdso_setup(void)
{
struct lib32_elfinfo v32;
struct lib64_elfinfo v64;
- v32.hdr = vdso32_kbase;
-#ifdef CONFIG_PPC64
- v64.hdr = vdso64_kbase;
-#endif
- if (vdso_do_find_sections(&v32, &v64))
- return -1;
-
- if (vdso_fixup_datapage(&v32, &v64))
+#ifdef CONFIG_VDSO32
+ if (vdso_setup32(&v32))
return -1;
-
- if (vdso_fixup_features(&v32, &v64))
+#endif
+#ifdef CONFIG_PPC64
+ if (vdso_setup64(&v64))
return -1;
+#endif
if (vdso_fixup_alt_funcs(&v32, &v64))
return -1;
diff --git a/arch/powerpc/kernel/vdso_common.c b/arch/powerpc/kernel/vdso_common.c
new file mode 100644
index 000000000000..ac25d66134fb
--- /dev/null
+++ b/arch/powerpc/kernel/vdso_common.c
@@ -0,0 +1,221 @@
+#ifndef BITS
+#define BITS 32
+#endif
+
+#undef Elf_Ehdr
+#undef Elf_Sym
+#undef Elf_Shdr
+
+#define _CONCAT3(a, b, c) a ## b ## c
+#define CONCAT3(a, b, c) _CONCAT3(a, b, c)
+#define Elf_Ehdr CONCAT3(Elf, BITS, _Ehdr)
+#define Elf_Sym CONCAT3(Elf, BITS, _Sym)
+#define Elf_Shdr CONCAT3(Elf, BITS, _Shdr)
+#define VDSO_LBASE CONCAT3(VDSO, BITS, _LBASE)
+#define vdso_kbase CONCAT3(vdso, BITS, _kbase)
+#define vdso_pages CONCAT3(vdso, BITS, _pages)
+
+#undef pr_fmt
+#define pr_fmt(fmt) "vDSO" __stringify(BITS) ": " fmt
+
+#define lib_elfinfo CONCAT3(lib, BITS, _elfinfo)
+
+#define find_section CONCAT3(find_section, BITS,)
+static void * __init find_section(Elf_Ehdr *ehdr, const char *secname,
+ unsigned long *size)
+{
+ Elf_Shdr *sechdrs;
+ unsigned int i;
+ char *secnames;
+
+ /* Grab section headers and strings so we can tell who is who */
+ sechdrs = (void *)ehdr + ehdr->e_shoff;
+ secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
+
+ /* Find the section they want */
+ for (i = 1; i < ehdr->e_shnum; i++) {
+ if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
+ if (size)
+ *size = sechdrs[i].sh_size;
+ return (void *)ehdr + sechdrs[i].sh_offset;
+ }
+ }
+ if (size)
+ *size = 0;
+ return NULL;
+}
+
+#define find_symbol CONCAT3(find_symbol, BITS,)
+static Elf_Sym * __init find_symbol(struct lib_elfinfo *lib,
+ const char *symname)
+{
+ unsigned int i;
+ char name[MAX_SYMNAME], *c;
+
+ for (i = 0; i < (lib->dynsymsize / sizeof(Elf_Sym)); i++) {
+ if (lib->dynsym[i].st_name == 0)
+ continue;
+ strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
+ MAX_SYMNAME);
+ c = strchr(name, '@');
+ if (c)
+ *c = 0;
+ if (strcmp(symname, name) == 0)
+ return &lib->dynsym[i];
+ }
+ return NULL;
+}
+
+/*
+ * Note that we assume the section is .text and the symbol is relative to
+ * the library base.
+ */
+#define find_function CONCAT3(find_function, BITS,)
+static unsigned long __init find_function(struct lib_elfinfo *lib,
+ const char *symname)
+{
+ Elf_Sym *sym = find_symbol(lib, symname);
+
+ if (sym == NULL) {
+ pr_warn("function %s not found !\n", symname);
+ return 0;
+ }
+#if defined(VDS64_HAS_DESCRIPTORS) && (BITS == 64)
+ return *((u64 *)(vdso64_kbase + sym->st_value - VDSO64_LBASE)) -
+ VDSO64_LBASE;
+#else
+ return sym->st_value - VDSO_LBASE;
+#endif
+}
+
+#define vdso_do_func_patch CONCAT3(vdso_do_func_patch, BITS,)
+static int __init vdso_do_func_patch(struct lib_elfinfo *v,
+ const char *orig, const char *fix)
+{
+ Elf_Sym *sym_gen, *sym_fix;
+
+ sym_gen = find_symbol(v, orig);
+ if (sym_gen == NULL) {
+ pr_err("Can't find symbol %s !\n", orig);
+ return -1;
+ }
+ if (fix == NULL) {
+ sym_gen->st_name = 0;
+ return 0;
+ }
+ sym_fix = find_symbol(v, fix);
+ if (sym_fix == NULL) {
+ pr_err("Can't find symbol %s !\n", fix);
+ return -1;
+ }
+ sym_gen->st_value = sym_fix->st_value;
+ sym_gen->st_size = sym_fix->st_size;
+ sym_gen->st_info = sym_fix->st_info;
+ sym_gen->st_other = sym_fix->st_other;
+ sym_gen->st_shndx = sym_fix->st_shndx;
+
+ return 0;
+}
+
+#define vdso_do_find_sections CONCAT3(vdso_do_find_sections, BITS,)
+static __init int vdso_do_find_sections(struct lib_elfinfo *v)
+{
+ void *sect;
+
+ /*
+ * Locate symbol tables & text section
+ */
+ v->dynsym = find_section(v->hdr, ".dynsym", &v->dynsymsize);
+ v->dynstr = find_section(v->hdr, ".dynstr", NULL);
+ if (v->dynsym == NULL || v->dynstr == NULL) {
+ pr_err("required symbol section not found\n");
+ return -1;
+ }
+
+ sect = find_section(v->hdr, ".text", NULL);
+ if (sect == NULL) {
+ pr_err("the .text section was not found\n");
+ return -1;
+ }
+ v->text = sect - vdso_kbase;
+
+ return 0;
+}
+
+#define vdso_fixup_datapage CONCAT3(vdso_fixup_datapage, BITS,)
+static __init int vdso_fixup_datapage(struct lib_elfinfo *v)
+{
+ Elf_Sym *sym = find_symbol(v, "__kernel_datapage_offset");
+
+ if (sym == NULL) {
+ pr_err("Can't find symbol __kernel_datapage_offset !\n");
+ return -1;
+ }
+ *((int *)(vdso_kbase + sym->st_value - VDSO_LBASE)) =
+ (vdso_pages << PAGE_SHIFT) - (sym->st_value - VDSO_LBASE);
+
+ return 0;
+}
+
+#define vdso_fixup_features CONCAT3(vdso_fixup_features, BITS,)
+static __init int vdso_fixup_features(struct lib_elfinfo *v)
+{
+ unsigned long size;
+ void *start;
+
+ start = find_section(v->hdr, "__ftr_fixup", &size);
+ if (start)
+ do_feature_fixups(cur_cpu_spec->cpu_features,
+ start, start + size);
+
+ start = find_section(v->hdr, "__mmu_ftr_fixup", &size);
+ if (start)
+ do_feature_fixups(cur_cpu_spec->mmu_features,
+ start, start + size);
+
+#ifdef CONFIG_PPC64
+ start = find_section(v->hdr, "__fw_ftr_fixup", &size);
+ if (start)
+ do_feature_fixups(powerpc_firmware_features,
+ start, start + size);
+#endif /* CONFIG_PPC64 */
+
+ start = find_section(v->hdr, "__lwsync_fixup", &size);
+ if (start)
+ do_lwsync_fixups(cur_cpu_spec->cpu_features,
+ start, start + size);
+
+ return 0;
+}
+
+#define vdso_setup CONCAT3(vdso_setup, BITS,)
+static __init int vdso_setup(struct lib_elfinfo *v)
+{
+ v->hdr = vdso_kbase;
+
+ if (vdso_do_find_sections(v))
+ return -1;
+ if (vdso_fixup_datapage(v))
+ return -1;
+ if (vdso_fixup_features(v))
+ return -1;
+ return 0;
+}
+
+
+#undef find_section
+#undef find_symbol
+#undef find_function
+#undef vdso_do_func_patch
+#undef vdso_do_find_sections
+#undef vdso_fixup_datapage
+#undef vdso_fixup_features
+#undef vdso_setup
+
+#undef VDSO_LBASE
+#undef vdso_kbase
+#undef vdso_pages
+#undef lib_elfinfo
+#undef BITS
+#undef _CONCAT3
+#undef CONCAT3
--
2.10.1
More information about the Linuxppc-dev
mailing list