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From: Adhemerval Zanella <azanella@sourceware.org> To: glibc-cvs@sourceware.org Subject: [glibc/azanella/rtld-shared] elf: Define a new dynamic section tag - DT_GNU_FLAGS_1 (BZ #22745) Date: Mon, 27 Sep 2021 18:54:02 +0000 (GMT) [thread overview] Message-ID: <20210927185402.3DF293857C6E@sourceware.org> (raw) https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=319756f2c27ed51a6011fb7e0d01251b8295a8d9 commit 319756f2c27ed51a6011fb7e0d01251b8295a8d9 Author: Vivek Das Mohapatra <vivek@collabora.com> Date: Thu Jul 8 17:32:48 2021 +0100 elf: Define a new dynamic section tag - DT_GNU_FLAGS_1 (BZ #22745) Define a new flags section DT_GNU_FLAGS_1 (no more bits are available in DT_GNU_FLAGS). One flag is currently defined: DF_GNU_1_UNIQUE. libc and its companion DSOs (libpthread et al) should have this section and flag set. Checked on x86_64-linux-gnu and i686-linux-gnu. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> Diff: --- elf/elf.h | 7 ++++++- elf/get-dynamic-info.h | 12 ++++++++++++ include/elf.h | 2 ++ include/link.h | 1 + 4 files changed, 21 insertions(+), 1 deletion(-) diff --git a/elf/elf.h b/elf/elf.h index 4738dfa28f..f24b6579b3 100644 --- a/elf/elf.h +++ b/elf/elf.h @@ -898,6 +898,7 @@ typedef struct Dyn.d_un.d_val field of the Elf*_Dyn structure. This follows Sun's approach. */ #define DT_VALRNGLO 0x6ffffd00 +#define DT_GNU_FLAGS_1 0x6ffffdf4 /* GNU extension flags */ #define DT_GNU_PRELINKED 0x6ffffdf5 /* Prelinking timestamp */ #define DT_GNU_CONFLICTSZ 0x6ffffdf6 /* Size of conflict section */ #define DT_GNU_LIBLISTSZ 0x6ffffdf7 /* Size of library list */ @@ -912,7 +913,7 @@ typedef struct #define DT_SYMINENT 0x6ffffdff /* Entry size of syminfo */ #define DT_VALRNGHI 0x6ffffdff #define DT_VALTAGIDX(tag) (DT_VALRNGHI - (tag)) /* Reverse order! */ -#define DT_VALNUM 12 +#define DT_VALNUM 13 /* DT_* entries which fall between DT_ADDRRNGHI & DT_ADDRRNGLO use the Dyn.d_un.d_ptr field of the Elf*_Dyn structure. @@ -1001,6 +1002,10 @@ typedef struct #define DF_1_WEAKFILTER 0x20000000 #define DF_1_NOCOMMON 0x40000000 +/* State flags selectable in the `d_un.d_val' element of the DT_GNU_FLAGS_1 + entry in the dynamic section. */ +#define DF_GNU_1_UNIQUE 0x00000001 /* Load max 1 copy of this DSO. */ + /* Flags for the feature selection in DT_FEATURE_1. */ #define DTF_1_PARINIT 0x00000001 #define DTF_1_CONFEXP 0x00000002 diff --git a/elf/get-dynamic-info.h b/elf/get-dynamic-info.h index 4aa2058abf..63efa94e14 100644 --- a/elf/get-dynamic-info.h +++ b/elf/get-dynamic-info.h @@ -160,6 +160,18 @@ elf_get_dynamic_info (struct link_map *l) if (l->l_flags_1 & DF_1_NOW) info[DT_BIND_NOW] = info[VERSYMIDX (DT_FLAGS_1)]; } + if (info[DT_VALTAGIDX (DT_GNU_FLAGS_1) + + DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM + DT_EXTRANUM] != NULL) + { + l->l_gnu_flags_1 = info[DT_VALTAGIDX (DT_GNU_FLAGS_1) + + DT_NUM + DT_THISPROCNUM + + DT_VERSIONTAGNUM + DT_EXTRANUM]->d_un.d_val; + + if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES) + && l->l_gnu_flags_1 & ~DT_GNU_1_SUPPORTED_MASK) + _dl_debug_printf ("\nWARNING: Unsupported flag value(s) of 0x%x in DT_GNU_FLAGS_1.\n", + l->l_gnu_flags_1 & ~DT_GNU_1_SUPPORTED_MASK); + } if (info[DT_RUNPATH] != NULL) /* If both RUNPATH and RPATH are given, the latter is ignored. */ info[DT_RPATH] = NULL; diff --git a/include/elf.h b/include/elf.h index 14ed67ff67..5eee37c294 100644 --- a/include/elf.h +++ b/include/elf.h @@ -25,5 +25,7 @@ (DF_1_NOW | DF_1_NODELETE | DF_1_INITFIRST | DF_1_NOOPEN \ | DF_1_ORIGIN | DF_1_NODEFLIB | DF_1_PIE) +#define DT_GNU_1_SUPPORTED_MASK DF_GNU_1_UNIQUE + #endif /* !_ISOMAC */ #endif /* elf.h */ diff --git a/include/link.h b/include/link.h index 484ee6cb1b..fd39c2207c 100644 --- a/include/link.h +++ b/include/link.h @@ -284,6 +284,7 @@ struct link_map unsigned int l_used; /* Various flag words. */ + ElfW(Word) l_gnu_flags_1; ElfW(Word) l_feature_1; ElfW(Word) l_flags_1; ElfW(Word) l_flags;
next reply other threads:[~2021-09-27 18:54 UTC|newest] Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-09-27 18:54 Adhemerval Zanella [this message] -- strict thread matches above, loose matches on Subject: below -- 2021-08-10 13:41 Adhemerval Zanella 2021-08-10 12:42 Adhemerval Zanella 2021-08-09 20:31 Adhemerval Zanella 2021-08-09 20:25 Adhemerval Zanella 2021-08-09 20:17 Adhemerval Zanella
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