From 2301ed1c9af1316b4bad3747d2b03f7d44940f87 Mon Sep 17 00:00:00 2001 From: Szabolcs Nagy Date: Thu, 25 Apr 2019 13:46:01 +0100 Subject: [PATCH] aarch64: add STO_AARCH64_VARIANT_PCS and DT_AARCH64_VARIANT_PCS The bottom 2 bits of st_other are used for visibility, the top 6 bits are de facto reserved for processor specific use. This patch defines a bits to mark function symbols that follow a variant procedure call standard with different register usage convention. A dynamic tag is also defined that marks modules with R__JUMP_SLOT relocations referencing symbols marked with STO_AARCH64_VARIANT_PCS. This can be used by dynamic linkers that support lazy binding to decide what registers need to be preserved during symbol resolution. binutils/ChangeLog: * readelf.c (get_aarch64_dynamic_type): Handle DT_AARCH64_VARIANT_PCS. (get_aarch64_symbol_other): New, handles STO_AARCH64_VARIANT_PCS. (get_symbol_other): Call get_aarch64_symbol_other. include/ChangeLog: * elf/aarch64.h (DT_AARCH64_VARIANT_PCS): Define. (STO_AARCH64_VARIANT_PCS): Define. --- binutils/ChangeLog | 6 ++++++ binutils/readelf.c | 20 ++++++++++++++++++++ include/ChangeLog | 5 +++++ include/elf/aarch64.h | 5 +++++ 4 files changed, 36 insertions(+) diff --git a/binutils/ChangeLog b/binutils/ChangeLog index 79bfaee9086..ef9fa5ac712 100644 --- a/binutils/ChangeLog +++ b/binutils/ChangeLog @@ -1,3 +1,9 @@ +2019-05-24 Szabolcs Nagy + + * readelf.c (get_aarch64_dynamic_type): Handle DT_AARCH64_VARIANT_PCS. + (get_aarch64_symbol_other): New, handles STO_AARCH64_VARIANT_PCS. + (get_symbol_other): Call get_aarch64_symbol_other. + 2019-05-24 Alan Modra * objdump.c (disassemble_bytes): Set WIDE_OUTPUT in flags. diff --git a/binutils/readelf.c b/binutils/readelf.c index 9d2810437e4..23ffd866003 100644 --- a/binutils/readelf.c +++ b/binutils/readelf.c @@ -1810,6 +1810,7 @@ get_aarch64_dynamic_type (unsigned long type) { case DT_AARCH64_BTI_PLT: return "AARCH64_BTI_PLT"; case DT_AARCH64_PAC_PLT: return "AARCH64_PAC_PLT"; + case DT_AARCH64_VARIANT_PCS: return "AARCH64_VARIANT_PCS"; default: return NULL; } @@ -11101,6 +11102,22 @@ get_solaris_symbol_visibility (unsigned int visibility) } } +static const char * +get_aarch64_symbol_other (unsigned int other) +{ + static char buf[32]; + + if (other & STO_AARCH64_VARIANT_PCS) + { + other &= ~STO_AARCH64_VARIANT_PCS; + if (other == 0) + return "VARIANT_PCS"; + snprintf (buf, sizeof buf, "VARIANT_PCS | %x", other); + return buf; + } + return NULL; +} + static const char * get_mips_symbol_other (unsigned int other) { @@ -11212,6 +11229,9 @@ get_symbol_other (Filedata * filedata, unsigned int other) switch (filedata->file_header.e_machine) { + case EM_AARCH64: + result = get_aarch64_symbol_other (other); + break; case EM_MIPS: result = get_mips_symbol_other (other); break; diff --git a/include/ChangeLog b/include/ChangeLog index 2e8408402fb..4132bfec3d3 100644 --- a/include/ChangeLog +++ b/include/ChangeLog @@ -1,3 +1,8 @@ +2019-05-24 Szabolcs Nagy + + * elf/aarch64.h (DT_AARCH64_VARIANT_PCS): Define. + (STO_AARCH64_VARIANT_PCS): Define. + 2019-05-24 Alan Modra * elf/ppc64.h (R_PPC64_PLTSEQ_NOTOC, R_PPC64_PLTCALL_NOTOC), diff --git a/include/elf/aarch64.h b/include/elf/aarch64.h index 44665476265..721378abf86 100644 --- a/include/elf/aarch64.h +++ b/include/elf/aarch64.h @@ -38,6 +38,11 @@ /* Processor specific dynamic array tags. */ #define DT_AARCH64_BTI_PLT (DT_LOPROC + 1) #define DT_AARCH64_PAC_PLT (DT_LOPROC + 3) +#define DT_AARCH64_VARIANT_PCS (DT_LOPROC + 5) + +/* AArch64-specific values for st_other. */ +#define STO_AARCH64_VARIANT_PCS 0x80 /* Symbol may follow different call + convention from the base PCS. */ /* Relocation types. */ -- 2.30.2