stack trace support: fix check on symbol name presence

The output format of the stack trace is supposed to be different
depending on whether symbol names are available in the build.

However, the check only verified the validity of the pointer, not of the
string pointed to (which could be empty).

This commit fixes the check so that the original output:

mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x5e000
 > /lib/libc-2.10.1.so(_IO_file_doallocate+0x8c) [0x68a38]
 > /lib/libc-2.10.1.so(_IO_doallocbuf+0x6c) [0x78574]
 > /lib/libc-2.10.1.so(_IO_file_overflow+0x184) [0x7763c]
 > /lib/libc-2.10.1.so(_IO_file_xsputn+0x88) [0x76aac]
 > /lib/libc-2.10.1.so(_IO_puts+0xc8) [0x6b64c]
 > /bin/busybox(+0x0) [0x62c60]
 > /bin/busybox(+0x0) [0x4940]
 > /bin/busybox(+0x0) [0x499c]
 > /bin/busybox(+0x0) [0x4e08]
 > /lib/libc-2.10.1.so(__libc_init_first+0x30c) [0x1f84c]
 > /lib/libc-2.10.1.so(__libc_start_main+0xd8) [0x1f9f8]

becomes:

mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x5e000
 > /lib/libc-2.10.1.so(_IO_file_doallocate+0x8c) [0x68a38]
 > /lib/libc-2.10.1.so(_IO_doallocbuf+0x6c) [0x78574]
 > /lib/libc-2.10.1.so(_IO_file_overflow+0x184) [0x7763c]
 > /lib/libc-2.10.1.so(_IO_file_xsputn+0x88) [0x76aac]
 > /lib/libc-2.10.1.so(_IO_puts+0xc8) [0x6b64c]
 > /bin/busybox() [0x62c60]
 > /bin/busybox() [0x4940]
 > /bin/busybox() [0x499c]
 > /bin/busybox() [0x4e08]
 > /lib/libc-2.10.1.so(__libc_init_first+0x30c) [0x1f84c]
 > /lib/libc-2.10.1.so(__libc_start_main+0xd8) [0x1f9f8]

Signed-off-by: Thomas De Schampheleire <thomas.de.schampheleire@gmail.com>
Acked-by: Masatake YAMATO <yamato@redhat.com>
This commit is contained in:
Thomas De Schampheleire 2014-11-06 13:59:04 +01:00 committed by Dmitry V. Levin
parent 993198deb3
commit 22deda33c6

View File

@ -427,7 +427,7 @@ print_call_cb(void *dummy,
unw_word_t function_offset,
unsigned long true_offset)
{
if (symbol_name)
if (symbol_name && (symbol_name[0] != '\0'))
tprintf(STACK_ENTRY_SYMBOL_FMT);
else if (binary_filename)
tprintf(STACK_ENTRY_NOSYMBOL_FMT);