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| author | Jan Beulich <jbeulich@suse.com> | 2012-09-26 11:53:38 +0200 |
|---|---|---|
| committer | Jan Beulich <jbeulich@suse.com> | 2012-09-26 11:53:38 +0200 |
| commit | 4047479dfa0ae519ecac19528e01c2816f0c34bc (patch) | |
| tree | df72d0def68210a1c01ede6c13713483b3c0d9ea /xen/common/symbols.c | |
| parent | fa23df25a24ad67035d1f361e2554a8f9b56cb28 (diff) | |
| download | xen-4047479dfa0ae519ecac19528e01c2816f0c34bc.tar.gz xen-4047479dfa0ae519ecac19528e01c2816f0c34bc.tar.bz2 xen-4047479dfa0ae519ecac19528e01c2816f0c34bc.zip | |
x86: slightly improve stack trace on debug builds
As was rather obvious from crashes recently happening in stage testing,
the debug hypervisor, in that special case, has a drawback compared to
the non-debug one: When a call through a bad pointer happens, there's
no frame, and the top level (and frequently most important for
analysis) stack entry would get skipped:
(XEN) ----[ Xen-4.3-unstable x86_64 debug=y Not tainted ]----
(XEN) CPU: 1
(XEN) RIP: e008:[<0000000000000000>] ???
(XEN) RFLAGS: 0000000000010046 CONTEXT: hypervisor
(XEN) rax: 0000000000000008 rbx: 0000000000000001 rcx: 0000000000000003
(XEN) rdx: 0000003db54eb700 rsi: 7fffffffffffffff rdi: 0000000000000001
(XEN) rbp: ffff8302357e7ee0 rsp: ffff8302357e7e58 r8: 0000000000000000
(XEN) r9: 000000000000003e r10: ffff8302357e7f18 r11: ffff8302357e7f18
(XEN) r12: ffff8302357ee340 r13: ffff82c480263980 r14: ffff8302357ee3d0
(XEN) r15: 0000000000000001 cr0: 000000008005003b cr4: 00000000000026f0
(XEN) cr3: 00000000bf473000 cr2: 0000000000000000
(XEN) ds: 0000 es: 0000 fs: 0000 gs: 0000 ss: 0000 cs: e008
(XEN) Xen stack trace from rsp=ffff8302357e7e58:
(XEN) ffff82c4801a3d05 ffff8302357eca70 0000000800000020 ffff82c4802ead60
(XEN) 0000000000000001 ffff8302357e7ea0 ffff82c48016bf07 0000000000000000
(XEN) 0000000000000000 ffff8302357e7ee0 fffff830fffff830 0000000000000046
(XEN) ffff8302357e7f18 ffff82c480263980 ffff8302357e7f18 0000000000000000
(XEN) 0000000000000000 ffff8302357e7f10 ffff82c48015c2be 8302357dc0000fff
...
(XEN) Xen call trace:
(XEN) [<0000000000000000>] ???
(XEN) [<ffff82c48015c2be>] idle_loop+0x6c/0x7a
(XEN)
(XEN) Pagetable walk from 0000000000000000:
Since the bad pointer is being printed anyway (as part of the register
state), replace it with the top of stack value in such a case.
With the introduction of is_active_kernel_text(), use it also at the
(few) other suitable places (I intentionally didn't replace the use in
xen/arch/arm/mm.c - while it would be functionally correct, the
dependency on system_state wouldn't be from an abstract perspective).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
Diffstat (limited to 'xen/common/symbols.c')
| -rw-r--r-- | xen/common/symbols.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/xen/common/symbols.c b/xen/common/symbols.c index 4054ba01cc..83b2b58b59 100644 --- a/xen/common/symbols.c +++ b/xen/common/symbols.c @@ -93,6 +93,12 @@ static unsigned int get_symbol_offset(unsigned long pos) return name - symbols_names; } +bool_t is_active_kernel_text(unsigned long addr) +{ + return (is_kernel_text(addr) || + (system_state == SYS_STATE_boot && is_kernel_inittext(addr))); +} + const char *symbols_lookup(unsigned long addr, unsigned long *symbolsize, unsigned long *offset, @@ -104,7 +110,7 @@ const char *symbols_lookup(unsigned long addr, namebuf[KSYM_NAME_LEN] = 0; namebuf[0] = 0; - if (!is_kernel_text(addr) && !is_kernel_inittext(addr)) + if (!is_active_kernel_text(addr)) return NULL; /* do a binary search on the sorted symbols_addresses array */ |