From 4dca2d3a7b43bf99bd6a567870a3144af4e763ef Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Fri, 4 Feb 2022 15:54:59 -0300 Subject: [PATCH] hppa: Fix bind-now audit (BZ #28857) On hppa, a function pointer returned by la_symbind is actually a function descriptor has the plabel bit set (bit 30). This must be cleared to get the actual address of the descriptor. If the descriptor has been bound, the first word of the descriptor is the physical address of theA function, otherwise, the first word of the descriptor points to a trampoline in the PLT. This patch also adds a workaround on tests because on hppa (and it seems to be the only ABI I have see it), some shared library adds a dynamic PLT relocation to am empty symbol name: $ readelf -r elf/tst-audit25mod1.so [...] Relocation section '.rela.plt' at offset 0x464 contains 6 entries: Offset Info Type Sym.Value Sym. Name + Addend 00002008 00000081 R_PARISC_IPLT 508 [...] It breaks some assumptions on the test, where a symbol with an empty name ("") is passed on la_symbind. Checked on x86_64-linux-gnu and hppa-linux-gnu. (cherry picked from commit 9e94f57484a2aba0fe67ea2059b5843f651887c2) --- elf/Makefile | 2 +- elf/dl-audit.c | 3 ++- elf/tst-auditmod24a.c | 4 +++- elf/tst-auditmod24d.c | 4 +++- elf/tst-auditmod25.c | 2 +- sysdeps/hppa/dl-lookupcfg.h | 8 +++++--- 6 files changed, 15 insertions(+), 8 deletions(-) diff --git a/elf/Makefile b/elf/Makefile index 38e5793f35..fe954374c9 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -2072,7 +2072,7 @@ $(objpfx)tst-audit24c.out: $(objpfx)tst-auditmod24c.so $(objpfx)tst-audit24c: $(objpfx)tst-audit24amod1.so \ $(objpfx)tst-audit24amod2.so tst-audit24c-ENV = LD_BIND_NOW=1 LD_AUDIT=$(objpfx)tst-auditmod24c.so -LDFLAGS-tst-audit24b = -Wl,-z,lazy +LDFLAGS-tst-audit24c = -Wl,-z,lazy $(objpfx)tst-audit24d.out: $(objpfx)tst-auditmod24d.so $(objpfx)tst-audit24d: $(objpfx)tst-audit24dmod1.so \ diff --git a/elf/dl-audit.c b/elf/dl-audit.c index 72a50717ef..ec9b032eae 100644 --- a/elf/dl-audit.c +++ b/elf/dl-audit.c @@ -257,7 +257,8 @@ _dl_audit_symbind (struct link_map *l, struct reloc_result *reloc_result, reloc_result->flags = flags; } - DL_FIXUP_BINDNOW_RELOC (value, new_value, sym.st_value); + if (flags & LA_SYMB_ALTVALUE) + DL_FIXUP_BINDNOW_RELOC (value, new_value, sym.st_value); } void diff --git a/elf/tst-auditmod24a.c b/elf/tst-auditmod24a.c index d8e88f3984..3075dfae2f 100644 --- a/elf/tst-auditmod24a.c +++ b/elf/tst-auditmod24a.c @@ -110,5 +110,7 @@ la_symbind32 (Elf32_Sym *sym, unsigned int ndx, return sym->st_value; } - abort (); + if (symname[0] != '\0') + abort (); + return sym->st_value; } diff --git a/elf/tst-auditmod24d.c b/elf/tst-auditmod24d.c index 8c803ecc0a..badc6be451 100644 --- a/elf/tst-auditmod24d.c +++ b/elf/tst-auditmod24d.c @@ -116,5 +116,7 @@ la_symbind32 (Elf32_Sym *sym, unsigned int ndx, } } - abort (); + if (symname[0] != '\0') + abort (); + return sym->st_value; } diff --git a/elf/tst-auditmod25.c b/elf/tst-auditmod25.c index 526f5c54bc..20640a8daf 100644 --- a/elf/tst-auditmod25.c +++ b/elf/tst-auditmod25.c @@ -72,7 +72,7 @@ la_symbind32 (Elf32_Sym *sym, unsigned int ndx, unsigned int *flags, const char *symname) #endif { - if (*refcook != -1 && *defcook != -1) + if (*refcook != -1 && *defcook != -1 && symname[0] != '\0') fprintf (stderr, "la_symbind: %s %u\n", symname, *flags & (LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT) ? 1 : 0); return sym->st_value; diff --git a/sysdeps/hppa/dl-lookupcfg.h b/sysdeps/hppa/dl-lookupcfg.h index f4f00714fa..92fd0b7c84 100644 --- a/sysdeps/hppa/dl-lookupcfg.h +++ b/sysdeps/hppa/dl-lookupcfg.h @@ -80,7 +80,9 @@ void attribute_hidden _dl_unmap (struct link_map *map); /* Extract the code address from a fixup value */ #define DL_FIXUP_VALUE_CODE_ADDR(value) ((value).ip) #define DL_FIXUP_VALUE_ADDR(value) ((uintptr_t) &(value)) -#define DL_FIXUP_ADDR_VALUE(addr) (*(struct fdesc *) (addr)) +/* Clear the plabel bit to get the actual address of the descriptor. */ +#define DL_FIXUP_ADDR_VALUE(addr) \ + (*(DL_FIXUP_VALUE_TYPE *) ((uintptr_t) (addr) & ~2)) #define DL_FIXUP_BINDNOW_ADDR_VALUE(addr) (addr) -#define DL_FIXUP_BINDNOW_RELOC(value, new_value, st_value) \ - (*value) = *(struct fdesc *) (st_value) +#define DL_FIXUP_BINDNOW_RELOC(value, new_value, st_value) \ + *(value) = *(DL_FIXUP_VALUE_TYPE *) ((uintptr_t) (new_value) & ~2)