gdb/gdb-rhel-7329-vandps-clobbers-registers-7-of-13.patch
Guinevere Larsen 3c528c0bf9 Backport amd64 decoding fixes
Resolves: RHEL-93580
2025-05-29 13:56:54 -03:00

56 lines
1.7 KiB
Diff

From FEDORA_PATCHES Mon Sep 17 00:00:00 2001
From: Tom de Vries <tdevries@suse.de>
Date: Fri, 7 Mar 2025 09:25:33 +0100
Subject: gdb-rhel-7329-vandps-clobbers-registers-7-of-13.patch
;; [gdb/tdep] Fix rip-relative insn handling in amd64_get_used_input_int_reg
;; (Tom de Vries, RHEL-7329)
I wanted to add a unit test for an an rip-relative amd64 insn, so I did:
...
$ gcc -fPIE hello.c
...
and used an rip-relative insn from main:
...
4005db: 48 8d 3d 1e 00 00 00 lea 0x1e(%rip),%rdi
...
While writing the unit test, I found that amd64_get_used_input_int_reg returns
rbp as input register.
Fix this by using rip_relative_p in amd64_get_used_input_int_reg to handle
this case.
Tested on x86_64-linux.
diff --git a/gdb/amd64-tdep.c b/gdb/amd64-tdep.c
--- a/gdb/amd64-tdep.c
+++ b/gdb/amd64-tdep.c
@@ -1264,7 +1264,7 @@ amd64_get_used_input_int_regs (const struct amd64_insn *details,
used_regs_mask |= 1 << base;
used_regs_mask |= 1 << idx;
}
- else
+ else if (!rip_relative_p (modrm))
{
used_regs_mask |= 1 << rm;
}
@@ -3447,6 +3447,17 @@ test_amd64_get_insn_details (void)
SELF_CHECK (amd64_get_used_input_int_regs (&details, false)
== ((1 << EAX_REG_NUM)));
SELF_CHECK (rip_relative_offset (&details) == 0);
+
+ /* INSN: lea 0x1e(%rip),%rdi, rex prefix. */
+ insn = { 0x48, 0x8d, 0x3d, 0x1e, 0x00, 0x00, 0x00 };
+ amd64_get_insn_details (insn.data (), &details);
+ SELF_CHECK (details.opcode_len == 1);
+ SELF_CHECK (details.enc_prefix_offset == 0);
+ SELF_CHECK (details.opcode_offset == 1);
+ SELF_CHECK (details.modrm_offset == 2);
+ SELF_CHECK (amd64_get_used_input_int_regs (&details, false)
+ == (1 << EDI_REG_NUM));
+ SELF_CHECK (rip_relative_offset (&details) == 3);
}
static void