The ls (lookup symbol) and zr (reboot) commands use xmon's getstring()
helper to read a string argument from the xmon prompt. This function
skips over leading whitespace, but doesn't check if the first
"non-whitespace" character is a newline which causes some odd
behaviour (<enter> indicates a the enter key was pressed):
0:mon> ls printk<enter>
printk: c0000000001680c4
0:mon> ls<enter>
printk<enter>
Symbol '
printk' not found.
0:mon>
With commit 2d9b332d99 ("powerpc/xmon: Allow passing an argument to
ppc_md.restart()") we have a similar problem with the zr command.
Previously zr took no arguments so "zr<enter> would trigger a reboot.
With that patch applied a second newline needs to be sent in order for
the reboot to occur. Fix this by checking if the leading whitespace
ended on a newline:
0:mon> ls<enter>
Symbol '' not found.
Fixes: 2d9b332d99 ("powerpc/xmon: Allow passing an argument to ppc_md.restart()")
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200217041343.2454-1-oohall@gmail.com
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