Re: [Crash-utility] [PATCH 1/3] arm64: relax symbol filters

----- Original Message ----- > We need to pass some absolute symbols through, but the highest bit test > is filtering all of them out. Remove that, and filter more specifically. > --- > arm64.c | 4 ++-- > defs.h | 3 +++ > 2 files changed, 5 insertions(+), 2 deletions(-) > > diff --git a/arm64.c b/arm64.c > index 5f8e2f6852434..8cfb863d1bfe2 100644 > --- a/arm64.c > +++ b/arm64.c > @@ -305,7 +305,7 @@ arm64_verify_symbol(const char *name, ulong value, char > type) > if (!name || !strlen(name)) > return FALSE; > > - if (((type == 'A') || (type == 'a')) && (highest_bit_long(value) != 63)) > + if ((type == 'A') && (HAS_SUFFIX(name, ".c") || HAS_SUFFIX(name, ".o"))) > return FALSE; > > if ((value == 0) && > @@ -315,7 +315,7 @@ arm64_verify_symbol(const char *name, ulong value, char > type) > if (STREQ(name, "$d") || STREQ(name, "$x")) > return FALSE; > > - if ((type == 'A') && STRNEQ(name, "__crc_")) > + if ((type == 'A') && (STRNEQ(name, "__crc_") || STRNEQ(name, > "__reg_num_"))) > return FALSE; > > if (!(machdep->flags & KSYMS_START) && STREQ(name, "idmap_pg_dir")) > diff --git a/defs.h b/defs.h > index 7004619017e41..1bcd1b3b177db 100644 > --- a/defs.h > +++ b/defs.h > @@ -155,6 +155,9 @@ static inline int string_exists(char *s) { return (s ? > TRUE : FALSE); } > (strcmp((char *)(A), (char *)(B)) == 0)) > #define STRNEQ(A, B) (string_exists((char *)A) && string_exists((char > *)B) && \ > (strncmp((char *)(A), (char *)(B), strlen((char *)(B))) == 0)) > +#define HAS_SUFFIX(s, suffix) (string_exists((char *)s) && > string_exists((char *)suffix) && \ > + strlen((char *)s) > strlen((char *)suffix) && \ > + (strcmp((char *)(s) + strlen((char *)s) - strlen((char *)suffix), > (char *)suffix) == 0)) > #define BZERO(S, N) (memset(S, NULLCHAR, N)) > #define BCOPY(S, D, C) (memcpy(D, S, C)) > #define BNEG(S, N) (memset(S, 0xff, N)) > -- > 2.4.3 Hi Andrew, Hey, I appreciate the arm/arm64 interest! Let's start with this patch first... The "upper-level" symbol table kept by the crash-specific source code is only concerned with symbols that are kernel virtual addresses. Accordingly, the absolute symbols are stripped, and the ARM64 symbol table normally starts like this: crash> sym -l fffffe0000080000 (t) .head.text fffffe0000080000 (T) _text fffffe0000080000 (t) efi_head fffffe0000080040 (t) pe_header fffffe0000080044 (t) coff_header fffffe0000080058 (t) optional_header fffffe0000080070 (t) extra_header_fields fffffe00000800f8 (t) section_table fffffe0000081000 (T) stext fffffe0000081024 (t) preserve_boot_args ... With your patch 1/3 applied, it starts like this: crash> syms -l 0 (A) _kernel_flags_le 1 (a) __reg_num_x1 1 (a) __reg_num_x1 1 (a) __reg_num_x1 1 (a) __reg_num_x1 1 (a) __reg_num_x1 1 (a) __reg_num_x1 1 (a) __reg_num_x1 2 (a) __reg_num_x2 2 (a) __reg_num_x2 2 (a) __reg_num_x2 2 (a) __reg_num_x2 2 (a) __reg_num_x2 2 (a) __reg_num_x2 2 (a) __reg_num_x2 3 (a) __reg_num_x3 3 (a) __reg_num_x3 3 (a) __reg_num_x3 3 (a) __reg_num_x3 3 (a) __reg_num_x3 3 (a) __reg_num_x3 3 (a) __reg_num_x3 4 (a) __reg_num_x4 4 (a) __reg_num_x4 4 (a) __reg_num_x4 4 (a) __reg_num_x4 4 (a) __reg_num_x4 4 (a) __reg_num_x4 4 (a) __reg_num_x4 5 (a) __reg_num_x5 5 (a) __reg_num_x5 5 (a) __reg_num_x5 5 (a) __reg_num_x5 5 (a) __reg_num_x5 5 (a) __reg_num_x5 5 (a) __reg_num_x5 6 (a) __reg_num_x6 6 (a) __reg_num_x6 6 (a) __reg_num_x6 6 (a) __reg_num_x6 6 (a) __reg_num_x6 6 (a) __reg_num_x6 6 (a) __reg_num_x6 7 (a) __reg_num_x7 7 (a) __reg_num_x7 7 (a) __reg_num_x7 7 (a) __reg_num_x7 7 (a) __reg_num_x7 7 (a) __reg_num_x7 7 (a) __reg_num_x7 8 (a) __reg_num_x8 8 (a) __reg_num_x8 8 (a) __reg_num_x8 8 (a) __reg_num_x8 8 (a) __reg_num_x8 8 (a) __reg_num_x8 8 (a) __reg_num_x8 9 (a) __reg_num_x9 9 (a) __reg_num_x9 9 (a) __reg_num_x9 9 (a) __reg_num_x9 9 (a) __reg_num_x9 9 (a) __reg_num_x9 9 (a) __reg_num_x9 a (a) __reg_num_x10 a (a) __reg_num_x10 a (a) __reg_num_x10 a (a) __reg_num_x10 a (a) __reg_num_x10 a (a) __reg_num_x10 a (a) __reg_num_x10 b (a) __reg_num_x11 b (a) __reg_num_x11 b (a) __reg_num_x11 b (a) __reg_num_x11 b (a) __reg_num_x11 b (a) __reg_num_x11 b (a) __reg_num_x11 c (a) __reg_num_x12 c (a) __reg_num_x12 c (a) __reg_num_x12 c (a) __reg_num_x12 c (a) __reg_num_x12 c (a) __reg_num_x12 c (a) __reg_num_x12 d (a) __reg_num_x13 d (a) __reg_num_x13 d (a) __reg_num_x13 d (a) __reg_num_x13 d (a) __reg_num_x13 d (a) __reg_num_x13 d (a) __reg_num_x13 e (a) __reg_num_x14 e (a) __reg_num_x14 e (a) __reg_num_x14 e (a) __reg_num_x14 e (a) __reg_num_x14 e (a) __reg_num_x14 e (a) __reg_num_x14 f (a) __reg_num_x15 f (a) __reg_num_x15 f (a) __reg_num_x15 f (a) __reg_num_x15 f (a) __reg_num_x15 f (a) __reg_num_x15 f (a) __reg_num_x15 10 (a) __reg_num_x16 10 (a) __reg_num_x16 10 (a) __reg_num_x16 10 (a) __reg_num_x16 10 (a) __reg_num_x16 10 (a) __reg_num_x16 10 (a) __reg_num_x16 11 (a) __reg_num_x17 11 (a) __reg_num_x17 11 (a) __reg_num_x17 11 (a) __reg_num_x17 11 (a) __reg_num_x17 11 (a) __reg_num_x17 11 (a) __reg_num_x17 12 (a) __reg_num_x18 12 (a) __reg_num_x18 12 (a) __reg_num_x18 12 (a) __reg_num_x18 12 (a) __reg_num_x18 12 (a) __reg_num_x18 12 (a) __reg_num_x18 13 (a) __reg_num_x19 13 (a) __reg_num_x19 13 (a) __reg_num_x19 13 (a) __reg_num_x19 13 (a) __reg_num_x19 13 (a) __reg_num_x19 13 (a) __reg_num_x19 14 (a) __reg_num_x20 14 (a) __reg_num_x20 14 (a) __reg_num_x20 14 (a) __reg_num_x20 14 (a) __reg_num_x20 14 (a) __reg_num_x20 14 (a) __reg_num_x20 15 (a) __reg_num_x21 15 (a) __reg_num_x21 15 (a) __reg_num_x21 15 (a) __reg_num_x21 15 (a) __reg_num_x21 15 (a) __reg_num_x21 15 (a) __reg_num_x21 16 (a) __reg_num_x22 16 (a) __reg_num_x22 16 (a) __reg_num_x22 16 (a) __reg_num_x22 16 (a) __reg_num_x22 16 (a) __reg_num_x22 16 (a) __reg_num_x22 17 (a) __reg_num_x23 17 (a) __reg_num_x23 17 (a) __reg_num_x23 17 (a) __reg_num_x23 17 (a) __reg_num_x23 17 (a) __reg_num_x23 17 (a) __reg_num_x23 18 (a) __reg_num_x24 18 (a) __reg_num_x24 18 (a) __reg_num_x24 18 (a) __reg_num_x24 18 (a) __reg_num_x24 18 (a) __reg_num_x24 18 (a) __reg_num_x24 19 (a) __reg_num_x25 19 (a) __reg_num_x25 19 (a) __reg_num_x25 19 (a) __reg_num_x25 19 (a) __reg_num_x25 19 (a) __reg_num_x25 19 (a) __reg_num_x25 1a (a) __reg_num_x26 1a (a) __reg_num_x26 1a (a) __reg_num_x26 1a (a) __reg_num_x26 1a (a) __reg_num_x26 1a (a) __reg_num_x26 1a (a) __reg_num_x26 1b (a) __reg_num_x27 1b (a) __reg_num_x27 1b (a) __reg_num_x27 1b (a) __reg_num_x27 1b (a) __reg_num_x27 1b (a) __reg_num_x27 1b (a) __reg_num_x27 1c (a) __reg_num_x28 1c (a) __reg_num_x28 1c (a) __reg_num_x28 1c (a) __reg_num_x28 1c (a) __reg_num_x28 1c (a) __reg_num_x28 1c (a) __reg_num_x28 1d (a) __reg_num_x29 1d (a) __reg_num_x29 1d (a) __reg_num_x29 1d (a) __reg_num_x29 1d (a) __reg_num_x29 1d (a) __reg_num_x29 1d (a) __reg_num_x29 1e (a) __reg_num_x30 1e (a) __reg_num_x30 1e (a) __reg_num_x30 1e (a) __reg_num_x30 1e (a) __reg_num_x30 1e (a) __reg_num_x30 1e (a) __reg_num_x30 1f (a) __reg_num_xzr 1f (a) __reg_num_xzr 1f (a) __reg_num_xzr 1f (a) __reg_num_xzr 1f (a) __reg_num_xzr 1f (a) __reg_num_xzr 1f (a) __reg_num_xzr

200 (A) PECOFF_FILE_ALIGNMENT 1000 (A) stext_offset 80000 (A) _kernel_offset_le 1460000 (A) _kernel_size_le fffffe0000080000 (t) .head.text fffffe0000080000 (T) _text fffffe0000080000 (t) efi_head fffffe0000080040 (t) pe_header ... But keeping any absolute symbols below ".head.text" screws things up. Say for example, here's a normal "rd -S" call: crash> rd -S fffffe035a2f6580 100 fffffe035a2f6580: 0000000000000000 [kmalloc-16384] fffffe035a2f6590: 0040410000000002 0000000000000000 fffffe035a2f65a0: 0000000000000000 0000000000000001 fffffe035a2f65b0: [task_struct] 0000000000000002 fffffe035a2f65c0: 000000010c4ac06a 0000000100000000 fffffe035a2f65d0: 0000007800000078 0000000000000078 fffffe035a2f65e0: fair_sched_class 0000000000000400 fffffe035a2f65f0: 0000000000400000 0000000000000001 fffffe035a2f6600: 0000000000000000 0000000000000000 fffffe035a2f6610: fffffe03ffec5878 [task_struct] fffffe035a2f6620: 0000000000000001 000754096e1781d0 fffffe035a2f6630: 0000000157d0df88 000000004c7c03e4 fffffe035a2f6640: 0000000157cffbf4 0000000000000013 fffffe035a2f6650: 0000000000000001 [kmalloc-192] fffffe035a2f6660: [kmalloc-512] 0000000000000000 fffffe035a2f6670: 000754096e169e3c 0000000000000000 fffffe035a2f6680: 0000000000000000 0000000000000000 fffffe035a2f6690: 0000b9f100000026 0000000000000026 fffffe035a2f66a0: [task_struct] [task_struct] fffffe035a2f66b0: 0000000000000000 0000000000000000 fffffe035a2f66c0: 000000000000000a 0000000000000000 fffffe035a2f66d0: 0000000000000000 fffffe03ffec5050 fffffe035a2f66e0: 0000000000000000 [kmalloc-1024] fffffe035a2f66f0: [task_struct] 0000000000000000 fffffe035a2f6700: 0000000000000000 0000000000000000 fffffe035a2f6710: 0000000000000000 0000000000000000 fffffe035a2f6720: 0000000000000000 0000000000000000 fffffe035a2f6730: 0000000000000000 0000000000000000 fffffe035a2f6740: 0000000000000001 0000000000000000 fffffe035a2f6750: [task_struct] 0000000000000000 fffffe035a2f6760: 0000000000000000 0000000000000000 crash> With your patch applied, it looks like this: crash> rd -S fffffe035a2f6580 100 fffffe035a2f6580: __reg_num_x1 [kmalloc-16384] fffffe035a2f6590: _kernel_size_le+18085866743922690 _kernel_flags_le fffffe035a2f65a0: _kernel_flags_le _kernel_flags_le fffffe035a2f65b0: [task_struct] __reg_num_x3 fffffe035a2f65c0: _kernel_size_le+4479828301 __reg_num_x1 fffffe035a2f65d0: _kernel_size_le+515374710904 __reg_num_xzr+89 fffffe035a2f65e0: fair_sched_class PECOFF_FILE_ALIGNMENT+512 fffffe035a2f65f0: _kernel_offset_le+3670016 __reg_num_x1 fffffe035a2f6600: _kernel_flags_le _kernel_flags_le fffffe035a2f6610: [task_struct] [task_struct] fffffe035a2f6620: _kernel_flags_le _kernel_size_le+2062727142285104 fffffe035a2f6630: _kernel_size_le+5760795604 _kernel_size_le+1409972385 fffffe035a2f6640: _kernel_size_le+5760749924 __reg_num_x20 fffffe035a2f6650: __reg_num_x1 [kmalloc-192] fffffe035a2f6660: [kmalloc-512] _kernel_flags_le fffffe035a2f6670: _kernel_size_le+2062727142285104 _kernel_size_le+1945805182 fffffe035a2f6680: _kernel_flags_le _kernel_flags_le fffffe035a2f6690: _kernel_size_le+204101119508525 __reg_num_xzr+14 fffffe035a2f66a0: [task_struct] [task_struct] fffffe035a2f66b0: _kernel_flags_le _kernel_flags_le fffffe035a2f66c0: __reg_num_x10 _kernel_flags_le fffffe035a2f66d0: _kernel_flags_le fffffe03ffee5050 fffffe035a2f66e0: _kernel_flags_le [kmalloc-1024] fffffe035a2f66f0: [task_struct] _kernel_flags_le fffffe035a2f6700: _kernel_flags_le _kernel_flags_le fffffe035a2f6710: _kernel_flags_le _kernel_flags_le fffffe035a2f6720: _kernel_flags_le _kernel_flags_le fffffe035a2f6730: _kernel_flags_le _kernel_flags_le fffffe035a2f6740: __reg_num_x1 _kernel_flags_le fffffe035a2f6750: [task_struct] _kernel_flags_le fffffe035a2f6760: _kernel_flags_le _kernel_flags_le crash>

As I understand it, you're only interested in the "_kernel_flags_le" value, so let's just key on that particular absolute symbol in arm64_verify_symbol(), and stash it aside for later use.