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| author | Chuck Ebbert <76306.1226@compuserve.com> | 2006-03-23 02:59:30 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-03-23 07:38:03 -0800 |
| commit | 4d7d8c82c181711d28c8336108330a9121f5ef07 (patch) | |
| tree | 2e1537702c1e8447dfbe5b5917333f58f4416c1a /arch | |
| parent | b824eb605ccba995fd32c6590aed365f93d48002 (diff) | |
| download | lwn-4d7d8c82c181711d28c8336108330a9121f5ef07.tar.gz lwn-4d7d8c82c181711d28c8336108330a9121f5ef07.zip | |
[PATCH] i386: multi-column stack backtraces
Print stack backtraces in multiple columns, saving screen space. Number of
columns is configurable and defaults to one so behavior is
backwards-compatible.
Also removes the brackets around addresses when printing more
that one entry per line so they print as:
<address>
instead of:
[<address>]
This helps multiple entries fit better on one line.
Original idea by Dave Jones, taken from x86_64.
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/i386/Kconfig.debug | 9 | ||||
| -rw-r--r-- | arch/i386/kernel/traps.c | 32 |
2 files changed, 36 insertions, 5 deletions
diff --git a/arch/i386/Kconfig.debug b/arch/i386/Kconfig.debug index bf32ecc9ad04..00108ba9a78d 100644 --- a/arch/i386/Kconfig.debug +++ b/arch/i386/Kconfig.debug @@ -31,6 +31,15 @@ config DEBUG_STACK_USAGE This option will slow down process creation somewhat. +config STACK_BACKTRACE_COLS + int "Stack backtraces per line" if DEBUG_KERNEL + range 1 3 + default 2 + help + Selects how many stack backtrace entries per line to display. + + This can save screen space when displaying traces. + comment "Page alloc debug is incompatible with Software Suspend on i386" depends on DEBUG_KERNEL && SOFTWARE_SUSPEND diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c index b814dbdcc91e..ee61988f61b5 100644 --- a/arch/i386/kernel/traps.c +++ b/arch/i386/kernel/traps.c @@ -112,12 +112,30 @@ static inline int valid_stack_ptr(struct thread_info *tinfo, void *p) p < (void *)tinfo + THREAD_SIZE - 3; } -static void print_addr_and_symbol(unsigned long addr, char *log_lvl) +/* + * Print CONFIG_STACK_BACKTRACE_COLS address/symbol entries per line. + */ +static inline int print_addr_and_symbol(unsigned long addr, char *log_lvl, + int printed) { - printk(log_lvl); + if (!printed) + printk(log_lvl); + +#if CONFIG_STACK_BACKTRACE_COLS == 1 printk(" [<%08lx>] ", addr); +#else + printk(" <%08lx> ", addr); +#endif print_symbol("%s", addr); - printk("\n"); + + printed = (printed + 1) % CONFIG_STACK_BACKTRACE_COLS; + + if (printed) + printk(" "); + else + printk("\n"); + + return printed; } static inline unsigned long print_context_stack(struct thread_info *tinfo, @@ -125,20 +143,24 @@ static inline unsigned long print_context_stack(struct thread_info *tinfo, char *log_lvl) { unsigned long addr; + int printed = 0; /* nr of entries already printed on current line */ #ifdef CONFIG_FRAME_POINTER while (valid_stack_ptr(tinfo, (void *)ebp)) { addr = *(unsigned long *)(ebp + 4); - print_addr_and_symbol(addr, log_lvl); + printed = print_addr_and_symbol(addr, log_lvl, printed); ebp = *(unsigned long *)ebp; } #else while (valid_stack_ptr(tinfo, stack)) { addr = *stack++; if (__kernel_text_address(addr)) - print_addr_and_symbol(addr, log_lvl); + printed = print_addr_and_symbol(addr, log_lvl, printed); } #endif + if (printed) + printk("\n"); + return ebp; } |