From: Jan Beulich <jbeulich@suse.com>
To: Binutils <binutils@sourceware.org>
Subject: [PATCH] x86-64: restrict PC32 -> PLT32 conversion
Date: Wed, 5 Jan 2022 12:14:40 +0100 [thread overview]
Message-ID: <bdbd75b4-68b1-0a67-a957-648fed3845d9@suse.com> (raw)
Neither non-64-bit code nor uses with a non-zero offset from a symbol
should be converted to PLT32, as an eventual PLT entry would not express
what was requested.
--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -8857,6 +8857,8 @@ output_branch (void)
off = 0;
}
+ frag_now->tc_frag_data.code64 = flag_code == CODE_64BIT;
+
/* 1 possible extra opcode + 4 byte displacement go in var part.
Pass reloc in fr_var. */
frag_var (rs_machine_dependent, 5, i.reloc[0], subtype, sym, off, p);
@@ -8985,8 +8987,8 @@ output_jump (void)
}
#if defined (OBJ_ELF) || defined (OBJ_MAYBE_ELF)
- if (size == 4
- && jump_reloc == NO_RELOC
+ if (flag_code == CODE_64BIT && size == 4
+ && jump_reloc == NO_RELOC && i.op[0].disps->X_add_number == 0
&& need_plt32_p (i.op[0].disps->X_add_symbol))
jump_reloc = BFD_RELOC_X86_64_PLT32;
#endif
@@ -12289,7 +12291,8 @@ md_estimate_size_before_relax (fragS *fr
else if (size == 2)
reloc_type = BFD_RELOC_16_PCREL;
#if defined (OBJ_ELF) || defined (OBJ_MAYBE_ELF)
- else if (need_plt32_p (fragP->fr_symbol))
+ else if (fragP->tc_frag_data.code64 && fragP->fr_offset == 0
+ && need_plt32_p (fragP->fr_symbol))
reloc_type = BFD_RELOC_X86_64_PLT32;
#endif
else
--- a/gas/config/tc-i386.h
+++ b/gas/config/tc-i386.h
@@ -283,6 +283,7 @@ struct i386_tc_frag_data
unsigned int mf_type : 3;
unsigned int classified : 1;
unsigned int branch_type : 3;
+ unsigned int code64 : 1; /* Only set by output_branch for now. */
};
/* We need to emit the right NOP pattern in .align frags. This is
next reply other threads:[~2022-01-05 11:14 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-05 11:14 Jan Beulich [this message]
2022-01-05 14:54 ` H.J. Lu
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