Merge branch 'work.set_fs-exec' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull uaccess/coredump updates from Al Viro:
 "set_fs() removal in coredump-related area - mostly Christoph's
  stuff..."

* 'work.set_fs-exec' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  binfmt_elf_fdpic: remove the set_fs(KERNEL_DS) in elf_fdpic_core_dump
  binfmt_elf: remove the set_fs(KERNEL_DS) in elf_core_dump
  binfmt_elf: remove the set_fs in fill_siginfo_note
  signal: refactor copy_siginfo_to_user32
  powerpc/spufs: simplify spufs core dumping
  powerpc/spufs: stop using access_ok
  powerpc/spufs: fix copy_to_user while atomic

arch/powerpc/platforms/cell/spufs/coredump.c

@@ -21,22 +21,6 @@
 
 #include "spufs.h"
 
-static ssize_t do_coredump_read(int num, struct spu_context *ctx, void *buffer,
-				size_t size, loff_t *off)
-{
-	u64 data;
-	int ret;
-
-	if (spufs_coredump_read[num].read)
-		return spufs_coredump_read[num].read(ctx, buffer, size, off);
-
-	data = spufs_coredump_read[num].get(ctx);
-	ret = snprintf(buffer, size, "0x%.16llx", data);
-	if (ret >= size)
-		return size;
-	return ++ret; /* count trailing NULL */
-}
-
 static int spufs_ctx_note_size(struct spu_context *ctx, int dfd)
 {
 	int i, sz, total = 0;
@@ -118,58 +102,43 @@ int spufs_coredump_extra_notes_size(void)
 static int spufs_arch_write_note(struct spu_context *ctx, int i,
 				  struct coredump_params *cprm, int dfd)
 {
-	loff_t pos = 0;
-	int sz, rc, total = 0;
-	const int bufsz = PAGE_SIZE;
-	char *name;
-	char fullname[80], *buf;
+	size_t sz = spufs_coredump_read[i].size;
+	char fullname[80];
 	struct elf_note en;
-	size_t skip;
-
-	buf = (void *)get_zeroed_page(GFP_KERNEL);
-	if (!buf)
-		return -ENOMEM;
-
-	name = spufs_coredump_read[i].name;
-	sz = spufs_coredump_read[i].size;
+	size_t ret;
 
-	sprintf(fullname, "SPU/%d/%s", dfd, name);
+	sprintf(fullname, "SPU/%d/%s", dfd, spufs_coredump_read[i].name);
 	en.n_namesz = strlen(fullname) + 1;
 	en.n_descsz = sz;
 	en.n_type = NT_SPU;
 
 	if (!dump_emit(cprm, &en, sizeof(en)))
-		goto Eio;
-
+		return -EIO;
 	if (!dump_emit(cprm, fullname, en.n_namesz))
-		goto Eio;
-
+		return -EIO;
 	if (!dump_align(cprm, 4))
-		goto Eio;
-
-	do {
-		rc = do_coredump_read(i, ctx, buf, bufsz, &pos);
-		if (rc > 0) {
-			if (!dump_emit(cprm, buf, rc))
-				goto Eio;
-			total += rc;
-		}
-	} while (rc == bufsz && total < sz);
+		return -EIO;
 
-	if (rc < 0)
-		goto out;
+	if (spufs_coredump_read[i].dump) {
+		ret = spufs_coredump_read[i].dump(ctx, cprm);
+		if (ret < 0)
+			return ret;
+	} else {
+		char buf[32];
 
-	skip = roundup(cprm->pos - total + sz, 4) - cprm->pos;
-	if (!dump_skip(cprm, skip))
-		goto Eio;
+		ret = snprintf(buf, sizeof(buf), "0x%.16llx",
+			       spufs_coredump_read[i].get(ctx));
+		if (ret >= sizeof(buf))
+			return sizeof(buf);
 
-	rc = 0;
-out:
-	free_page((unsigned long)buf);
-	return rc;
-Eio:
-	free_page((unsigned long)buf);
+		/* count trailing the NULL: */
+		if (!dump_emit(cprm, buf, ret + 1))
+			return -EIO;
+	}
+
+	if (!dump_skip(cprm, roundup(cprm->pos - ret + sz, 4) - cprm->pos))
 		return -EIO;
+	return 0;
 }
 
 int spufs_coredump_extra_notes_write(struct coredump_params *cprm)

arch/powerpc/platforms/cell/spufs/spufs.h

@@ -337,8 +337,7 @@ void spufs_dma_callback(struct spu *spu, int type);
 extern struct spu_coredump_calls spufs_coredump_calls;
 struct spufs_coredump_reader {
 	char *name;
-	ssize_t (*read)(struct spu_context *ctx,
-			char __user *buffer, size_t size, loff_t *pos);
+	ssize_t (*dump)(struct spu_context *ctx, struct coredump_params *cprm);
 	u64 (*get)(struct spu_context *ctx);
 	size_t size;
 };

arch/x86/ia32/ia32_signal.c

@@ -350,7 +350,7 @@ int ia32_setup_rt_frame(int sig, struct ksignal *ksig,
 	unsafe_put_user(*(__u64 *)set, (__u64 *)&frame->uc.uc_sigmask, Efault);
 	user_access_end();
 
-	if (__copy_siginfo_to_user32(&frame->info, &ksig->info, false))
+	if (__copy_siginfo_to_user32(&frame->info, &ksig->info))
 		return -EFAULT;
 
 	/* Set up registers for signal handler */

arch/x86/include/asm/compat.h

@@ -214,7 +214,11 @@ static inline bool in_compat_syscall(void)
 #endif
 
 struct compat_siginfo;
-int __copy_siginfo_to_user32(struct compat_siginfo __user *to,
-		const kernel_siginfo_t *from, bool x32_ABI);
+
+#ifdef CONFIG_X86_X32_ABI
+int copy_siginfo_to_user32(struct compat_siginfo __user *to,
+		const kernel_siginfo_t *from);
+#define copy_siginfo_to_user32 copy_siginfo_to_user32
+#endif /* CONFIG_X86_X32_ABI */
 
 #endif /* _ASM_X86_COMPAT_H */

arch/x86/kernel/signal.c

@@ -37,6 +37,7 @@
 #include <asm/vm86.h>
 
 #ifdef CONFIG_X86_64
+#include <linux/compat.h>
 #include <asm/proto.h>
 #include <asm/ia32_unistd.h>
 #endif /* CONFIG_X86_64 */
@@ -511,6 +512,31 @@ static int __setup_rt_frame(int sig, struct ksignal *ksig,
 }
 #endif /* CONFIG_X86_32 */
 
+#ifdef CONFIG_X86_X32_ABI
+static int x32_copy_siginfo_to_user(struct compat_siginfo __user *to,
+		const struct kernel_siginfo *from)
+{
+	struct compat_siginfo new;
+
+	copy_siginfo_to_external32(&new, from);
+	if (from->si_signo == SIGCHLD) {
+		new._sifields._sigchld_x32._utime = from->si_utime;
+		new._sifields._sigchld_x32._stime = from->si_stime;
+	}
+	if (copy_to_user(to, &new, sizeof(struct compat_siginfo)))
+		return -EFAULT;
+	return 0;
+}
+
+int copy_siginfo_to_user32(struct compat_siginfo __user *to,
+			   const struct kernel_siginfo *from)
+{
+	if (in_x32_syscall())
+		return x32_copy_siginfo_to_user(to, from);
+	return __copy_siginfo_to_user32(to, from);
+}
+#endif /* CONFIG_X86_X32_ABI */
+
 static int x32_setup_rt_frame(struct ksignal *ksig,
 			      compat_sigset_t *set,
 			      struct pt_regs *regs)
@@ -543,7 +569,7 @@ static int x32_setup_rt_frame(struct ksignal *ksig,
 	user_access_end();
 
 	if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
-		if (__copy_siginfo_to_user32(&frame->info, &ksig->info, true))
+		if (x32_copy_siginfo_to_user(&frame->info, &ksig->info))
 			return -EFAULT;
 	}
 

fs/binfmt_elf.c

@@ -1488,7 +1488,6 @@ static unsigned long vma_dump_size(struct vm_area_struct *vma,
 	    vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
 		u32 __user *header = (u32 __user *) vma->vm_start;
 		u32 word;
-		mm_segment_t fs = get_fs();
 		/*
 		 * Doing it this way gets the constant folded by GCC.
 		 */
@@ -1501,14 +1500,8 @@ static unsigned long vma_dump_size(struct vm_area_struct *vma,
 		magic.elfmag[EI_MAG1] = ELFMAG1;
 		magic.elfmag[EI_MAG2] = ELFMAG2;
 		magic.elfmag[EI_MAG3] = ELFMAG3;
-		/*
-		 * Switch to the user "segment" for get_user(),
-		 * then put back what elf_core_dump() had in place.
-		 */
-		set_fs(USER_DS);
 		if (unlikely(get_user(word, header)))
 			word = 0;
-		set_fs(fs);
 		if (word == magic.cmp)
 			return PAGE_SIZE;
 	}
@@ -1689,10 +1682,7 @@ static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
 static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata,
 		const kernel_siginfo_t *siginfo)
 {
-	mm_segment_t old_fs = get_fs();
-	set_fs(KERNEL_DS);
-	copy_siginfo_to_user((user_siginfo_t __user *) csigdata, siginfo);
-	set_fs(old_fs);
+	copy_siginfo_to_external(csigdata, siginfo);
 	fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata);
 }
 
@@ -2319,7 +2309,6 @@ static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
 static int elf_core_dump(struct coredump_params *cprm)
 {
 	int has_dumped = 0;
-	mm_segment_t fs;
 	int segs, i;
 	size_t vma_data_size = 0;
 	struct vm_area_struct *vma, *gate_vma;
@@ -2368,13 +2357,10 @@ static int elf_core_dump(struct coredump_params *cprm)
 	 * notes.  This also sets up the file header.
 	 */
 	if (!fill_note_info(&elf, e_phnum, &info, cprm->siginfo, cprm->regs))
-		goto cleanup;
+		goto end_coredump;
 
 	has_dumped = 1;
 
-	fs = get_fs();
-	set_fs(KERNEL_DS);
-
 	offset += sizeof(elf);				/* Elf header */
 	offset += segs * sizeof(struct elf_phdr);	/* Program headers */
 
@@ -2502,9 +2488,6 @@ static int elf_core_dump(struct coredump_params *cprm)
 	}
 
 end_coredump:
-	set_fs(fs);
-
-cleanup:
 	free_note_info(&info);
 	kfree(shdr4extnum);
 	kvfree(vma_filesz);

fs/binfmt_elf_fdpic.c

@@ -1549,7 +1549,6 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm)
 {
 #define	NUM_NOTES	6
 	int has_dumped = 0;
-	mm_segment_t fs;
 	int segs;
 	int i;
 	struct vm_area_struct *vma;
@@ -1589,31 +1588,31 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm)
 	/* alloc memory for large data structures: too large to be on stack */
 	elf = kmalloc(sizeof(*elf), GFP_KERNEL);
 	if (!elf)
-		goto cleanup;
+		goto end_coredump;
 	prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
 	if (!prstatus)
-		goto cleanup;
+		goto end_coredump;
 	psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
 	if (!psinfo)
-		goto cleanup;
+		goto end_coredump;
 	notes = kmalloc_array(NUM_NOTES, sizeof(struct memelfnote),
 			      GFP_KERNEL);
 	if (!notes)
-		goto cleanup;
+		goto end_coredump;
 	fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
 	if (!fpu)
-		goto cleanup;
+		goto end_coredump;
 #ifdef ELF_CORE_COPY_XFPREGS
 	xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
 	if (!xfpu)
-		goto cleanup;
+		goto end_coredump;
 #endif
 
 	for (ct = current->mm->core_state->dumper.next;
 					ct; ct = ct->next) {
 		tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
 		if (!tmp)
-			goto cleanup;
+			goto end_coredump;
 
 		tmp->thread = ct->task;
 		list_add(&tmp->list, &thread_list);
@@ -1678,9 +1677,6 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm)
 			  "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
 #endif
 
-	fs = get_fs();
-	set_fs(KERNEL_DS);
-
 	offset += sizeof(*elf);				/* Elf header */
 	offset += segs * sizeof(struct elf_phdr);	/* Program headers */
 
@@ -1788,9 +1784,6 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm)
 	}
 
 end_coredump:
-	set_fs(fs);
-
-cleanup:
 	while (!list_empty(&thread_list)) {
 		struct list_head *tmp = thread_list.next;
 		list_del(tmp);

fs/compat_binfmt_elf.c

@@ -43,7 +43,7 @@
  */
 #define user_long_t		compat_long_t
 #define user_siginfo_t		compat_siginfo_t
-#define copy_siginfo_to_user	copy_siginfo_to_user32
+#define copy_siginfo_to_external	copy_siginfo_to_external32
 
 /*
  * The machine-dependent core note format types are defined in elfcore-compat.h,

include/linux/compat.h

@@ -402,8 +402,15 @@ long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask,
 		       unsigned long bitmap_size);
 long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
 		       unsigned long bitmap_size);
-int copy_siginfo_from_user32(kernel_siginfo_t *to, const struct compat_siginfo __user *from);
-int copy_siginfo_to_user32(struct compat_siginfo __user *to, const kernel_siginfo_t *from);
+void copy_siginfo_to_external32(struct compat_siginfo *to,
+		const struct kernel_siginfo *from);
+int copy_siginfo_from_user32(kernel_siginfo_t *to,
+		const struct compat_siginfo __user *from);
+int __copy_siginfo_to_user32(struct compat_siginfo __user *to,
+		const kernel_siginfo_t *from);
+#ifndef copy_siginfo_to_user32
+#define copy_siginfo_to_user32 __copy_siginfo_to_user32
+#endif
 int get_compat_sigevent(struct sigevent *event,
 		const struct compat_sigevent __user *u_event);
 

include/linux/signal.h

@@ -24,6 +24,14 @@ static inline void clear_siginfo(kernel_siginfo_t *info)
 
 #define SI_EXPANSION_SIZE (sizeof(struct siginfo) - sizeof(struct kernel_siginfo))
 
+static inline void copy_siginfo_to_external(siginfo_t *to,
+					    const kernel_siginfo_t *from)
+{
+	memcpy(to, from, sizeof(*from));
+	memset(((char *)to) + sizeof(struct kernel_siginfo), 0,
+		SI_EXPANSION_SIZE);
+}
+
 int copy_siginfo_to_user(siginfo_t __user *to, const kernel_siginfo_t *from);
 int copy_siginfo_from_user(kernel_siginfo_t *to, const siginfo_t __user *from);
 

kernel/signal.c

@@ -3235,94 +3235,94 @@ int copy_siginfo_from_user(kernel_siginfo_t *to, const siginfo_t __user *from)
 }
 
 #ifdef CONFIG_COMPAT
-int copy_siginfo_to_user32(struct compat_siginfo __user *to,
+/**
+ * copy_siginfo_to_external32 - copy a kernel siginfo into a compat user siginfo
+ * @to: compat siginfo destination
+ * @from: kernel siginfo source
+ *
+ * Note: This function does not work properly for the SIGCHLD on x32, but
+ * fortunately it doesn't have to.  The only valid callers for this function are
+ * copy_siginfo_to_user32, which is overriden for x32 and the coredump code.
+ * The latter does not care because SIGCHLD will never cause a coredump.
+ */
+void copy_siginfo_to_external32(struct compat_siginfo *to,
 		const struct kernel_siginfo *from)
-#if defined(CONFIG_X86_X32_ABI) || defined(CONFIG_IA32_EMULATION)
-{
-	return __copy_siginfo_to_user32(to, from, in_x32_syscall());
-}
-int __copy_siginfo_to_user32(struct compat_siginfo __user *to,
-			     const struct kernel_siginfo *from, bool x32_ABI)
-#endif
 {
-	struct compat_siginfo new;
-	memset(&new, 0, sizeof(new));
+	memset(to, 0, sizeof(*to));
 
-	new.si_signo = from->si_signo;
-	new.si_errno = from->si_errno;
-	new.si_code  = from->si_code;
+	to->si_signo = from->si_signo;
+	to->si_errno = from->si_errno;
+	to->si_code  = from->si_code;
 	switch(siginfo_layout(from->si_signo, from->si_code)) {
 	case SIL_KILL:
-		new.si_pid = from->si_pid;
-		new.si_uid = from->si_uid;
+		to->si_pid = from->si_pid;
+		to->si_uid = from->si_uid;
 		break;
 	case SIL_TIMER:
-		new.si_tid     = from->si_tid;
-		new.si_overrun = from->si_overrun;
-		new.si_int     = from->si_int;
+		to->si_tid     = from->si_tid;
+		to->si_overrun = from->si_overrun;
+		to->si_int     = from->si_int;
 		break;
 	case SIL_POLL:
-		new.si_band = from->si_band;
-		new.si_fd   = from->si_fd;
+		to->si_band = from->si_band;
+		to->si_fd   = from->si_fd;
 		break;
 	case SIL_FAULT:
-		new.si_addr = ptr_to_compat(from->si_addr);
+		to->si_addr = ptr_to_compat(from->si_addr);
 #ifdef __ARCH_SI_TRAPNO
-		new.si_trapno = from->si_trapno;
+		to->si_trapno = from->si_trapno;
 #endif
 		break;
 	case SIL_FAULT_MCEERR:
-		new.si_addr = ptr_to_compat(from->si_addr);
+		to->si_addr = ptr_to_compat(from->si_addr);
 #ifdef __ARCH_SI_TRAPNO
-		new.si_trapno = from->si_trapno;
+		to->si_trapno = from->si_trapno;
 #endif
-		new.si_addr_lsb = from->si_addr_lsb;
+		to->si_addr_lsb = from->si_addr_lsb;
 		break;
 	case SIL_FAULT_BNDERR:
-		new.si_addr = ptr_to_compat(from->si_addr);
+		to->si_addr = ptr_to_compat(from->si_addr);
 #ifdef __ARCH_SI_TRAPNO
-		new.si_trapno = from->si_trapno;
+		to->si_trapno = from->si_trapno;
 #endif
-		new.si_lower = ptr_to_compat(from->si_lower);
-		new.si_upper = ptr_to_compat(from->si_upper);
+		to->si_lower = ptr_to_compat(from->si_lower);
+		to->si_upper = ptr_to_compat(from->si_upper);
 		break;
 	case SIL_FAULT_PKUERR:
-		new.si_addr = ptr_to_compat(from->si_addr);
+		to->si_addr = ptr_to_compat(from->si_addr);
 #ifdef __ARCH_SI_TRAPNO
-		new.si_trapno = from->si_trapno;
+		to->si_trapno = from->si_trapno;
 #endif
-		new.si_pkey = from->si_pkey;
+		to->si_pkey = from->si_pkey;
 		break;
 	case SIL_CHLD:
-		new.si_pid    = from->si_pid;
-		new.si_uid    = from->si_uid;
-		new.si_status = from->si_status;
-#ifdef CONFIG_X86_X32_ABI
-		if (x32_ABI) {
-			new._sifields._sigchld_x32._utime = from->si_utime;
-			new._sifields._sigchld_x32._stime = from->si_stime;
-		} else
-#endif
-		{
-			new.si_utime = from->si_utime;
-			new.si_stime = from->si_stime;
-		}
+		to->si_pid = from->si_pid;
+		to->si_uid = from->si_uid;
+		to->si_status = from->si_status;
+		to->si_utime = from->si_utime;
+		to->si_stime = from->si_stime;
 		break;
 	case SIL_RT:
-		new.si_pid = from->si_pid;
-		new.si_uid = from->si_uid;
-		new.si_int = from->si_int;
+		to->si_pid = from->si_pid;
+		to->si_uid = from->si_uid;
+		to->si_int = from->si_int;
 		break;
 	case SIL_SYS:
-		new.si_call_addr = ptr_to_compat(from->si_call_addr);
-		new.si_syscall   = from->si_syscall;
-		new.si_arch      = from->si_arch;
+		to->si_call_addr = ptr_to_compat(from->si_call_addr);
+		to->si_syscall   = from->si_syscall;
+		to->si_arch      = from->si_arch;
 		break;
 	}
+}
 
+int __copy_siginfo_to_user32(struct compat_siginfo __user *to,
+			   const struct kernel_siginfo *from)
+{
+	struct compat_siginfo new;
+
+	copy_siginfo_to_external32(&new, from);
 	if (copy_to_user(to, &new, sizeof(struct compat_siginfo)))
 		return -EFAULT;
-
 	return 0;
 }