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author | 2022-05-31 15:38:19 -0700 | |
---|---|---|
committer | 2022-06-06 14:17:23 +0200 | |
commit | 7e29ac5b51573b3370414810895fbcc959dddd45 (patch) | |
tree | 1dc9de7509e3c7ef6084067ea9de5e2f770049dd | |
parent | AArch64: Enable FP16 by default for Armv9-A. (diff) | |
download | binutils-gdb-gentoo/binutils-2.38.tar.gz binutils-gdb-gentoo/binutils-2.38.tar.bz2 binutils-gdb-gentoo/binutils-2.38.zip |
x86: Properly handle IFUNC function pointer referencegentoo/binutils-2.38
Update
commit 68c4956b1401de70173848a6bdf620cb42fa9358
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Tue Apr 26 09:08:54 2022 -0700
x86: Properly handle function pointer reference
to properly handle IFUNC function pointer reference. Since IFUNC symbol
value is only known at run-time, set pointer_equality_needed for IFUNC
function pointer reference in PDE so that it will be resolved to its PLT
entry directly.
bfd/
PR ld/29216
* elf32-i386.c (elf_i386_scan_relocs): Set pointer_equality_needed
for IFUNC function pointer reference in PDE.
* elf64-x86-64.c (elf_x86_64_scan_relocs): Likewise.
ld/
PR ld/29216
* testsuite/ld-ifunc/ifunc.exp: Run PR ld/29216 test.
* testsuite/ld-ifunc/pr29216.c: New file.
(cherry picked from commit 98a1627f19ca125476d5d58d9999c7a8d381f403)
(cherry picked from commit e1ea1dafff64a9be37d275dbcfc71ef08ef84324)
-rw-r--r-- | bfd/elf32-i386.c | 8 | ||||
-rw-r--r-- | bfd/elf64-x86-64.c | 8 | ||||
-rw-r--r-- | ld/testsuite/ld-ifunc/ifunc.exp | 9 | ||||
-rw-r--r-- | ld/testsuite/ld-ifunc/pr29216.c | 62 |
4 files changed, 85 insertions, 2 deletions
diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c index b034154fb97..3bc710096aa 100644 --- a/bfd/elf32-i386.c +++ b/bfd/elf32-i386.c @@ -1778,7 +1778,13 @@ elf_i386_scan_relocs (bfd *abfd, if (r_type == R_386_32 && (sec->flags & SEC_READONLY) == 0) func_pointer_ref = true; - else + + /* IFUNC symbol needs pointer equality in PDE so that + function pointer reference will be resolved to its + PLT entry directly. */ + if (!func_pointer_ref + || (bfd_link_pde (info) + && h->type == STT_GNU_IFUNC)) h->pointer_equality_needed = 1; } diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c index 7cf7959cdb1..16229b39dca 100644 --- a/bfd/elf64-x86-64.c +++ b/bfd/elf64-x86-64.c @@ -2221,7 +2221,13 @@ elf_x86_64_scan_relocs (bfd *abfd, struct bfd_link_info *info, && (r_type == R_X86_64_32 || r_type == R_X86_64_32S)))) func_pointer_ref = true; - else + + /* IFUNC symbol needs pointer equality in PDE so that + function pointer reference will be resolved to its + PLT entry directly. */ + if (!func_pointer_ref + || (bfd_link_pde (info) + && h->type == STT_GNU_IFUNC)) h->pointer_equality_needed = 1; } diff --git a/ld/testsuite/ld-ifunc/ifunc.exp b/ld/testsuite/ld-ifunc/ifunc.exp index 1cd8d388b26..fdb65d01f9f 100644 --- a/ld/testsuite/ld-ifunc/ifunc.exp +++ b/ld/testsuite/ld-ifunc/ifunc.exp @@ -714,6 +714,15 @@ run_ld_link_exec_tests [list \ "pr18841cn" \ "pr18841.out" \ ] \ + [list \ + "Run pr29216" \ + "$NOPIE_LDFLAGS" \ + "" \ + { pr29216.c } \ + "pr29216" \ + "pass.out" \ + "-fPIC" \ + ] \ ] # The pr23169 testcase is not valid. In general, you can't call ifunc diff --git a/ld/testsuite/ld-ifunc/pr29216.c b/ld/testsuite/ld-ifunc/pr29216.c new file mode 100644 index 00000000000..5019c723c2b --- /dev/null +++ b/ld/testsuite/ld-ifunc/pr29216.c @@ -0,0 +1,62 @@ +#include <stdio.h> + +static int +one (void) +{ + return -30; +} + +int foo (void) __attribute__ ((ifunc ("resolve_foo"))); + +void * +resolve_foo (void) +{ + return (void *) one; +} + +typedef int (*foo_p) (void); + +foo_p foo_ptr = foo; + +foo_p +__attribute__ ((noinline)) +get_foo_p (void) +{ + return foo_ptr; +} + +foo_p +__attribute__ ((noinline)) +get_foo (void) +{ + return foo; +} + +int +main (void) +{ + foo_p p; + + p = get_foo (); + if (p != foo) + __builtin_abort (); + if ((*p) () != -30) + __builtin_abort (); + + p = get_foo_p (); + if (p != foo) + __builtin_abort (); + if ((*p) () != -30) + __builtin_abort (); + + if (foo_ptr != foo) + __builtin_abort (); + if ((*foo_ptr) () != -30) + __builtin_abort (); + if (foo () != -30) + __builtin_abort (); + + printf ("PASS\n"); + + return 0; +} |