diff mbox series

elf: Make dl-fptr and dl-symaddr hppa specific

Message ID 20240731160104.2963895-1-adhemerval.zanella@linaro.org
State New
Headers show
Series elf: Make dl-fptr and dl-symaddr hppa specific | expand

Commit Message

Adhemerval Zanella Netto July 31, 2024, 4 p.m. UTC
With ia64 removal, the function descriptor supports is only used
by HPPA and new architectures do not seem leaning towards this
design.
---
 elf/dl-fptr.c             | 322 --------------------------------------
 elf/dl-symaddr.c          |  33 ----
 sysdeps/generic/dl-fptr.h |  45 ------
 sysdeps/hppa/dl-fptr.h    |  23 ++-
 4 files changed, 22 insertions(+), 401 deletions(-)
 delete mode 100644 elf/dl-fptr.c
 delete mode 100644 elf/dl-symaddr.c
 delete mode 100644 sysdeps/generic/dl-fptr.h

Comments

Florian Weimer Aug. 9, 2024, 3:28 p.m. UTC | #1
* Adhemerval Zanella:

> With ia64 removal, the function descriptor supports is only used
> by HPPA and new architectures do not seem leaning towards this
> design.

Looks okay.

Reviewed-by: Florian Weimer <fweimer@redhat.com>

Thanks,
Florian
diff mbox series

Patch

diff --git a/elf/dl-fptr.c b/elf/dl-fptr.c
deleted file mode 100644
index 575406ae44..0000000000
--- a/elf/dl-fptr.c
+++ /dev/null
@@ -1,322 +0,0 @@ 
-/* Manage function descriptors.  Generic version.
-   Copyright (C) 1999-2024 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <https://www.gnu.org/licenses/>.  */
-
-#include <libintl.h>
-#include <unistd.h>
-#include <string.h>
-#include <sys/param.h>
-#include <sys/mman.h>
-#include <link.h>
-#include <ldsodefs.h>
-#include <elf/dynamic-link.h>
-#include <dl-fptr.h>
-#include <dl-unmap-segments.h>
-#include <atomic.h>
-
-#ifndef ELF_MACHINE_BOOT_FPTR_TABLE_LEN
-/* ELF_MACHINE_BOOT_FPTR_TABLE_LEN should be greater than the number of
-   dynamic symbols in ld.so.  */
-# define ELF_MACHINE_BOOT_FPTR_TABLE_LEN 256
-#endif
-
-#ifndef ELF_MACHINE_LOAD_ADDRESS
-# error "ELF_MACHINE_LOAD_ADDRESS is not defined."
-#endif
-
-#ifndef COMPARE_AND_SWAP
-# define COMPARE_AND_SWAP(ptr, old, new) \
-  (catomic_compare_and_exchange_bool_acq (ptr, new, old) == 0)
-#endif
-
-ElfW(Addr) _dl_boot_fptr_table [ELF_MACHINE_BOOT_FPTR_TABLE_LEN];
-
-static struct local
-  {
-    struct fdesc_table *root;
-    struct fdesc *free_list;
-    unsigned int npages;		/* # of pages to allocate */
-    /* the next to members MUST be consecutive! */
-    struct fdesc_table boot_table;
-    struct fdesc boot_fdescs[1024];
-  }
-local =
-  {
-    .root = &local.boot_table,
-    .npages = 2,
-    .boot_table =
-      {
-	.len = sizeof (local.boot_fdescs) / sizeof (local.boot_fdescs[0]),
-	.first_unused = 0
-      }
-  };
-
-/* Create a new fdesc table and return a pointer to the first fdesc
-   entry.  The fdesc lock must have been acquired already.  */
-
-static struct fdesc_table *
-new_fdesc_table (struct local *l, size_t *size)
-{
-  size_t old_npages = l->npages;
-  size_t new_npages = old_npages + old_npages;
-  struct fdesc_table *new_table;
-
-  /* If someone has just created a new table, we return NULL to tell
-     the caller to use the new table.  */
-  if (! COMPARE_AND_SWAP (&l->npages, old_npages, new_npages))
-    return (struct fdesc_table *) NULL;
-
-  *size = old_npages * GLRO(dl_pagesize);
-  new_table = __mmap (NULL, *size,
-		      PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0);
-  if (new_table == MAP_FAILED)
-    _dl_signal_error (errno, NULL, NULL,
-		      N_("cannot map pages for fdesc table"));
-
-  new_table->len
-    = (*size - sizeof (*new_table)) / sizeof (struct fdesc);
-  new_table->first_unused = 1;
-  return new_table;
-}
-
-
-static ElfW(Addr)
-make_fdesc (ElfW(Addr) ip, ElfW(Addr) gp)
-{
-  struct fdesc *fdesc = NULL;
-  struct fdesc_table *root;
-  unsigned int old;
-  struct local *l;
-
-  ELF_MACHINE_LOAD_ADDRESS (l, local);
-
- retry:
-  root = l->root;
-  while (1)
-    {
-      old = root->first_unused;
-      if (old >= root->len)
-	break;
-      else if (COMPARE_AND_SWAP (&root->first_unused, old, old + 1))
-	{
-	  fdesc = &root->fdesc[old];
-	  goto install;
-	}
-    }
-
-  if (l->free_list)
-    {
-      /* Get it from free-list.  */
-      do
-	{
-	  fdesc = l->free_list;
-	  if (fdesc == NULL)
-	    goto retry;
-	}
-      while (! COMPARE_AND_SWAP ((ElfW(Addr) *) &l->free_list,
-				 (ElfW(Addr)) fdesc, fdesc->ip));
-    }
-  else
-    {
-      /* Create a new fdesc table.  */
-      size_t size;
-      struct fdesc_table *new_table = new_fdesc_table (l, &size);
-
-      if (new_table == NULL)
-	goto retry;
-
-      new_table->next = root;
-      if (! COMPARE_AND_SWAP ((ElfW(Addr) *) &l->root,
-			      (ElfW(Addr)) root,
-			      (ElfW(Addr)) new_table))
-	{
-	  /* Someone has just installed a new table. Return NULL to
-	     tell the caller to use the new table.  */
-	  __munmap (new_table, size);
-	  goto retry;
-	}
-
-      /* Note that the first entry was reserved while allocating the
-	 memory for the new page.  */
-      fdesc = &new_table->fdesc[0];
-    }
-
- install:
-  fdesc->ip = ip;
-  fdesc->gp = gp;
-
-  return (ElfW(Addr)) fdesc;
-}
-
-
-static inline ElfW(Addr) * __attribute__ ((always_inline))
-make_fptr_table (struct link_map *map)
-{
-  const ElfW(Sym) *symtab
-    = (const void *) D_PTR (map, l_info[DT_SYMTAB]);
-  const char *strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
-  ElfW(Addr) *fptr_table;
-  size_t size;
-  size_t len;
-
-  /* XXX Apparently the only way to find out the size of the dynamic
-     symbol section is to assume that the string table follows right
-     afterwards...  */
-  len = ((strtab - (char *) symtab)
-	 / map->l_info[DT_SYMENT]->d_un.d_val);
-  size = ((len * sizeof (fptr_table[0]) + GLRO(dl_pagesize) - 1)
-	  & -GLRO(dl_pagesize));
-  /* XXX We don't support here in the moment systems without MAP_ANON.
-     There probably are none for IA-64.  In case this is proven wrong
-     we will have to open /dev/null here and use the file descriptor
-     instead of the hard-coded -1.  */
-  fptr_table = __mmap (NULL, size,
-		       PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE,
-		       -1, 0);
-  if (fptr_table == MAP_FAILED)
-    _dl_signal_error (errno, NULL, NULL,
-		      N_("cannot map pages for fptr table"));
-
-  if (COMPARE_AND_SWAP ((ElfW(Addr) *) &map->l_mach.fptr_table,
-			(ElfW(Addr)) NULL, (ElfW(Addr)) fptr_table))
-    map->l_mach.fptr_table_len = len;
-  else
-    __munmap (fptr_table, len * sizeof (fptr_table[0]));
-
-  return map->l_mach.fptr_table;
-}
-
-
-ElfW(Addr)
-_dl_make_fptr (struct link_map *map, const ElfW(Sym) *sym,
-	       ElfW(Addr) ip)
-{
-  ElfW(Addr) *ftab = map->l_mach.fptr_table;
-  const ElfW(Sym) *symtab;
-  Elf_Symndx symidx;
-  struct local *l;
-
-  if (__glibc_unlikely (ftab == NULL))
-    ftab = make_fptr_table (map);
-
-  symtab = (const void *) D_PTR (map, l_info[DT_SYMTAB]);
-  symidx = sym - symtab;
-
-  if (symidx >= map->l_mach.fptr_table_len)
-    _dl_signal_error (0, NULL, NULL,
-		      N_("internal error: symidx out of range of fptr table"));
-
-  while (ftab[symidx] == 0)
-    {
-      /* GOT has already been relocated in elf_get_dynamic_info -
-	 don't try to relocate it again.  */
-      ElfW(Addr) fdesc
-	= make_fdesc (ip, map->l_info[DT_PLTGOT]->d_un.d_ptr);
-
-      if (__builtin_expect (COMPARE_AND_SWAP (&ftab[symidx], (ElfW(Addr)) NULL,
-					      fdesc), 1))
-	{
-	  /* No one has updated the entry and the new function
-	     descriptor has been installed.  */
-#if 0
-	  const char *strtab
-	    = (const void *) D_PTR (map, l_info[DT_STRTAB]);
-
-	  ELF_MACHINE_LOAD_ADDRESS (l, local);
-	  if (l->root != &l->boot_table
-	      || l->boot_table.first_unused > 20)
-	    _dl_debug_printf ("created fdesc symbol `%s' at %lx\n",
-			      strtab + sym->st_name, ftab[symidx]);
-#endif
-	  break;
-	}
-      else
-	{
-	  /* We created a duplicated function descriptor. We put it on
-	     free-list.  */
-	  struct fdesc *f = (struct fdesc *) fdesc;
-
-	  ELF_MACHINE_LOAD_ADDRESS (l, local);
-
-	  do
-	    f->ip = (ElfW(Addr)) l->free_list;
-	  while (! COMPARE_AND_SWAP ((ElfW(Addr) *) &l->free_list,
-				     f->ip, fdesc));
-	}
-    }
-
-  return ftab[symidx];
-}
-
-
-void
-_dl_unmap (struct link_map *map)
-{
-  ElfW(Addr) *ftab = map->l_mach.fptr_table;
-  struct fdesc *head = NULL, *tail = NULL;
-  size_t i;
-
-  _dl_unmap_segments (map);
-
-  if (ftab == NULL)
-    return;
-
-  /* String together the fdesc structures that are being freed.  */
-  for (i = 0; i < map->l_mach.fptr_table_len; ++i)
-    {
-      if (ftab[i])
-	{
-	  *(struct fdesc **) ftab[i] = head;
-	  head = (struct fdesc *) ftab[i];
-	  if (tail == NULL)
-	    tail = head;
-	}
-    }
-
-  /* Prepend the new list to the free_list: */
-  if (tail)
-    do
-      tail->ip = (ElfW(Addr)) local.free_list;
-    while (! COMPARE_AND_SWAP ((ElfW(Addr) *) &local.free_list,
-			       tail->ip, (ElfW(Addr)) head));
-
-  __munmap (ftab, (map->l_mach.fptr_table_len
-		   * sizeof (map->l_mach.fptr_table[0])));
-
-  map->l_mach.fptr_table = NULL;
-}
-
-
-ElfW(Addr)
-_dl_lookup_address (const void *address)
-{
-  ElfW(Addr) addr = (ElfW(Addr)) address;
-  struct fdesc_table *t;
-  unsigned long int i;
-
-  for (t = local.root; t != NULL; t = t->next)
-    {
-      i = (struct fdesc *) addr - &t->fdesc[0];
-      if (i < t->first_unused && addr == (ElfW(Addr)) &t->fdesc[i])
-	{
-	  addr = t->fdesc[i].ip;
-	  break;
-	}
-    }
-
-  return addr;
-}
diff --git a/elf/dl-symaddr.c b/elf/dl-symaddr.c
deleted file mode 100644
index b0299fdb35..0000000000
--- a/elf/dl-symaddr.c
+++ /dev/null
@@ -1,33 +0,0 @@ 
-/* Get the symbol address.  Generic version.
-   Copyright (C) 1999-2024 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <https://www.gnu.org/licenses/>.  */
-
-#include <ldsodefs.h>
-#include <dl-fptr.h>
-
-void *
-_dl_symbol_address (struct link_map *map, const ElfW(Sym) *ref)
-{
-  ElfW(Addr) value = SYMBOL_ADDRESS (map, ref, false);
-
-  /* Return the pointer to function descriptor. */
-  if (ELFW(ST_TYPE) (ref->st_info) == STT_FUNC)
-    return (void *) _dl_make_fptr (map, ref, value);
-  else
-    return (void *) value;
-}
-rtld_hidden_def (_dl_symbol_address)
diff --git a/sysdeps/generic/dl-fptr.h b/sysdeps/generic/dl-fptr.h
deleted file mode 100644
index 71cfb62411..0000000000
--- a/sysdeps/generic/dl-fptr.h
+++ /dev/null
@@ -1,45 +0,0 @@ 
-/* Function descriptors. Generic version.
-   Copyright (C) 1995-2024 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <https://www.gnu.org/licenses/>.  */
-
-#ifndef dl_fptr_h
-#define dl_fptr_h 1
-
-/* An FDESC is a function descriptor.  */
-
-struct fdesc
-  {
-    ElfW(Addr) ip;	/* code entry point */
-    ElfW(Addr) gp;	/* global pointer */
-  };
-
-struct fdesc_table
-  {
-    struct fdesc_table *next;
-    unsigned int len;			/* # of entries in fdesc table */
-    volatile unsigned int first_unused;	/* index of first available entry */
-    struct fdesc fdesc[0];
-  };
-
-struct link_map;
-
-extern ElfW(Addr) _dl_boot_fptr_table [];
-
-extern ElfW(Addr) _dl_make_fptr (struct link_map *, const ElfW(Sym) *,
-				 ElfW(Addr));
-
-#endif /* !dl_fptr_h */
diff --git a/sysdeps/hppa/dl-fptr.h b/sysdeps/hppa/dl-fptr.h
index 7c5eb0bd30..b7fd9cf71a 100644
--- a/sysdeps/hppa/dl-fptr.h
+++ b/sysdeps/hppa/dl-fptr.h
@@ -19,7 +19,28 @@ 
 #ifndef dl_hppa_fptr_h
 #define dl_hppa_fptr_h 1
 
-#include <sysdeps/generic/dl-fptr.h>
+/* An FDESC is a function descriptor.  */
+
+struct fdesc
+  {
+    ElfW(Addr) ip;	/* code entry point */
+    ElfW(Addr) gp;	/* global pointer */
+  };
+
+struct fdesc_table
+  {
+    struct fdesc_table *next;
+    unsigned int len;			/* # of entries in fdesc table */
+    volatile unsigned int first_unused;	/* index of first available entry */
+    struct fdesc fdesc[0];
+  };
+
+struct link_map;
+
+extern ElfW(Addr) _dl_boot_fptr_table [];
+
+extern ElfW(Addr) _dl_make_fptr (struct link_map *, const ElfW(Sym) *,
+				 ElfW(Addr));
 
 /* Initialize function pointer code. Call before relocation processing.  */
 extern void _dl_fptr_init (void);