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authorUlises Mendez Martinez <umendez@google.com>2026-09-04 15:07:09 +0000
committerJosh Poimboeuf <jpoimboe@kernel.org>2026-09-13 18:15:43 -0700
commit7e61560628d17ea6b1d8ee370f6d42694cff8758 (patch)
treee6080164b2f4c4c419894bdb3ce4d956ca9a98c5 /arch/arm/lib/delay-loop.S
downloadlinux-stable-7e61560628d17ea6b1d8ee370f6d42694cff8758.tar.gz
linux-stable-7e61560628d17ea6b1d8ee370f6d42694cff8758.zip
objtool: Validate disassembler headers in libopcodes probegrafted
commit 3f2de814c059 ("objtool: Fix libopcodes linking with static libraries") tested for libopcodes availability by linking a test snippet with a forward declaration of disassemble_init_for_target(). However, testing symbol linkage with an extern declaration only verifies the presence of the library (.so/.a) and bypasses checking for development headers (binutils-dev). On systems where libopcodes is present without development headers installed, the probe succeeds, enabling BUILD_DISAS. Subsequent compilation of objtool then fails: fatal error: 'bfd.h' file not found 113 | #include <bfd.h> Additionally, the probe invokes $(HOSTCC) without $(HOSTCFLAGS), ignoring any sysroot or include flags specified for the host compiler. Fix this by including <bfd.h> and <dis-asm.h> directly in the test snippet, passing $(HOSTCFLAGS) so host compiler options are respected, and defining PACKAGE="objtool" to satisfy the configuration check in <bfd.h>. Fixes: 3f2de814c059 ("objtool: Fix libopcodes linking with static libraries") Fixes: 436326bc525d ("objtool: fix build failure due to missing libopcodes check") Reported-by: Alice Ryhl <aliceryhl@google.com> Assisted-by: Antigravity:Gemini-Next Signed-off-by: Ulises Mendez Martinez <umendez@google.com> Link: https://patch.msgid.link/20260904150710.2997558-1-umendez@google.com Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Diffstat (limited to 'arch/arm/lib/delay-loop.S')
-rw-r--r--arch/arm/lib/delay-loop.S67
1 files changed, 67 insertions, 0 deletions
diff --git a/arch/arm/lib/delay-loop.S b/arch/arm/lib/delay-loop.S
new file mode 100644
index 000000000..33b08ca1c
--- /dev/null
+++ b/arch/arm/lib/delay-loop.S
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * linux/arch/arm/lib/delay.S
+ *
+ * Copyright (C) 1995, 1996 Russell King
+ */
+#include <linux/linkage.h>
+#include <linux/cfi_types.h>
+#include <asm/assembler.h>
+#include <asm/delay.h>
+
+#ifdef CONFIG_ARCH_RPC
+ .arch armv4
+#endif
+
+ .text
+
+.LC0: .word loops_per_jiffy
+.LC1: .word UDELAY_MULT
+
+/*
+ * loops = r0 * HZ * loops_per_jiffy / 1000000
+ *
+ * r0 <= 2000
+ * HZ <= 1000
+ */
+
+SYM_TYPED_FUNC_START(__loop_udelay)
+ ldr r2, .LC1
+ mul r0, r2, r0 @ r0 = delay_us * UDELAY_MULT
+ b __loop_const_udelay
+SYM_FUNC_END(__loop_udelay)
+
+SYM_TYPED_FUNC_START(__loop_const_udelay) @ 0 <= r0 <= 0xfffffaf0
+ ldr r2, .LC0
+ ldr r2, [r2]
+ umull r1, r0, r2, r0 @ r0-r1 = r0 * loops_per_jiffy
+ adds r1, r1, #0xffffffff @ rounding up ...
+ adcs r0, r0, r0 @ and right shift by 31
+ reteq lr
+ b __loop_delay
+SYM_FUNC_END(__loop_const_udelay)
+
+ .align 3
+
+@ Delay routine
+SYM_TYPED_FUNC_START(__loop_delay)
+ subs r0, r0, #1
+#if 0
+ retls lr
+ subs r0, r0, #1
+ retls lr
+ subs r0, r0, #1
+ retls lr
+ subs r0, r0, #1
+ retls lr
+ subs r0, r0, #1
+ retls lr
+ subs r0, r0, #1
+ retls lr
+ subs r0, r0, #1
+ retls lr
+ subs r0, r0, #1
+#endif
+ bhi __loop_delay
+ ret lr
+SYM_FUNC_END(__loop_delay)