* [PATCH] powerpc/xmon: Fix whitespace handling in getstring()
@ 2020-02-17 4:13 Oliver O'Halloran
2020-02-19 12:40 ` Michael Ellerman
0 siblings, 1 reply; 2+ messages in thread
From: Oliver O'Halloran @ 2020-02-17 4:13 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Oliver O'Halloran
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 2d9b332d99b ("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: 2d9b332d99b ("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>
---
arch/powerpc/xmon/xmon.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index e8c84d26..0ec9640 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -3435,6 +3435,11 @@ getstring(char *s, int size)
int c;
c = skipbl();
+ if (c == '\n') {
+ *s = 0;
+ return;
+ }
+
do {
if( size > 1 ){
*s++ = c;
--
2.9.5
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] powerpc/xmon: Fix whitespace handling in getstring()
2020-02-17 4:13 [PATCH] powerpc/xmon: Fix whitespace handling in getstring() Oliver O'Halloran
@ 2020-02-19 12:40 ` Michael Ellerman
0 siblings, 0 replies; 2+ messages in thread
From: Michael Ellerman @ 2020-02-19 12:40 UTC (permalink / raw)
To: Oliver O'Halloran, linuxppc-dev; +Cc: Oliver O'Halloran
On Mon, 2020-02-17 at 04:13:43 UTC, Oliver O'Halloran wrote:
> 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 2d9b332d99b ("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: 2d9b332d99b ("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>
Applied to powerpc fixes, thanks.
https://git.kernel.org/powerpc/c/066bc3576e653b615ee3f5230a89d69c8ebeeb71
cheers
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