From 7e61560628d17ea6b1d8ee370f6d42694cff8758 Mon Sep 17 00:00:00 2001 From: Ulises Mendez Martinez Date: Fri, 4 Sep 2026 15:07:09 +0000 Subject: objtool: Validate disassembler headers in libopcodes probe 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 Additionally, the probe invokes $(HOSTCC) without $(HOSTCFLAGS), ignoring any sysroot or include flags specified for the host compiler. Fix this by including and directly in the test snippet, passing $(HOSTCFLAGS) so host compiler options are respected, and defining PACKAGE="objtool" to satisfy the configuration check in . Fixes: 3f2de814c059 ("objtool: Fix libopcodes linking with static libraries") Fixes: 436326bc525d ("objtool: fix build failure due to missing libopcodes check") Reported-by: Alice Ryhl Assisted-by: Antigravity:Gemini-Next Signed-off-by: Ulises Mendez Martinez Link: https://patch.msgid.link/20260904150710.2997558-1-umendez@google.com Signed-off-by: Josh Poimboeuf --- lib/test_bitops.c | 139 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 139 insertions(+) create mode 100644 lib/test_bitops.c (limited to 'lib/test_bitops.c') diff --git a/lib/test_bitops.c b/lib/test_bitops.c new file mode 100644 index 000000000..55669624b --- /dev/null +++ b/lib/test_bitops.c @@ -0,0 +1,139 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2020 Intel Corporation + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include + +/* a tiny module only meant to test + * + * set/clear_bit + * get_count_order/long + */ + +/* use an enum because that's the most common BITMAP usage */ +enum bitops_fun { + BITOPS_4 = 4, + BITOPS_7 = 7, + BITOPS_11 = 11, + BITOPS_31 = 31, + BITOPS_88 = 88, + BITOPS_LAST = 255, + BITOPS_LENGTH = 256 +}; + +static DECLARE_BITMAP(g_bitmap, BITOPS_LENGTH); + +static unsigned int order_comb[][2] = { + {0x00000003, 2}, + {0x00000004, 2}, + {0x00001fff, 13}, + {0x00002000, 13}, + {0x50000000, 31}, + {0x80000000, 31}, + {0x80003000, 32}, +}; + +#ifdef CONFIG_64BIT +static unsigned long order_comb_long[][2] = { + {0x0000000300000000, 34}, + {0x0000000400000000, 34}, + {0x00001fff00000000, 45}, + {0x0000200000000000, 45}, + {0x5000000000000000, 63}, + {0x8000000000000000, 63}, + {0x8000300000000000, 64}, +}; +#endif + +static int __init test_fns(void) +{ + static volatile __always_used unsigned long tmp __initdata; + unsigned long *buf __free(kfree) = NULL; + unsigned int i, n; + ktime_t time; + + buf = kmalloc_array(10000, sizeof(unsigned long), GFP_KERNEL); + if (!buf) + return -ENOMEM; + + get_random_bytes(buf, 10000 * sizeof(unsigned long)); + time = ktime_get(); + + for (n = 0; n < BITS_PER_LONG; n++) + for (i = 0; i < 10000; i++) + tmp = fns(buf[i], n); + + time = ktime_get() - time; + pr_err("fns: %18llu ns\n", time); + + return 0; +} + +static int __init test_bitops_startup(void) +{ + int i, bit_set; + + pr_info("Starting bitops test\n"); + set_bit(BITOPS_4, g_bitmap); + set_bit(BITOPS_7, g_bitmap); + set_bit(BITOPS_11, g_bitmap); + set_bit(BITOPS_31, g_bitmap); + set_bit(BITOPS_88, g_bitmap); + + for (i = 0; i < ARRAY_SIZE(order_comb); i++) { + if (order_comb[i][1] != get_count_order(order_comb[i][0])) + pr_warn("get_count_order wrong for %x\n", + order_comb[i][0]); + } + + for (i = 0; i < ARRAY_SIZE(order_comb); i++) { + if (order_comb[i][1] != get_count_order_long(order_comb[i][0])) + pr_warn("get_count_order_long wrong for %x\n", + order_comb[i][0]); + } + +#ifdef CONFIG_64BIT + for (i = 0; i < ARRAY_SIZE(order_comb_long); i++) { + if (order_comb_long[i][1] != + get_count_order_long(order_comb_long[i][0])) + pr_warn("get_count_order_long wrong for %lx\n", + order_comb_long[i][0]); + } +#endif + + barrier(); + + clear_bit(BITOPS_4, g_bitmap); + clear_bit(BITOPS_7, g_bitmap); + clear_bit(BITOPS_11, g_bitmap); + clear_bit(BITOPS_31, g_bitmap); + clear_bit(BITOPS_88, g_bitmap); + + bit_set = find_first_bit(g_bitmap, BITOPS_LAST); + if (bit_set != BITOPS_LAST) + pr_err("ERROR: FOUND SET BIT %d\n", bit_set); + + test_fns(); + + pr_info("Completed bitops test\n"); + + return 0; +} + +static void __exit test_bitops_unstartup(void) +{ +} + +module_init(test_bitops_startup); +module_exit(test_bitops_unstartup); + +MODULE_AUTHOR("Jesse Brandeburg , Wei Yang "); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Bit testing module"); -- cgit v1.3.1