xen: fix unspecified behavior in tr invocation

[XEN PATCH] xen: fix unspecified behavior in tr invocation

Nicola Vetrini posted 1 patch 4 months ago

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git fetch https://gitlab.com/xen-project/patchew/xen tags/patchew/df5119a0e5f617ed1a2756dfca77368596e2c369.1750949938.git.nicola.vetrini@bugseng.com

xen/scripts/Makefile.asm-generic | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

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[XEN PATCH] xen: fix unspecified behavior in tr invocation

Posted by Nicola Vetrini 4 months ago

The result of the command is undefined according to the specification if
the "string2" argument in tr is shorter than "string1". GNU tr behaves
correctly by extending "string2" to repeat the last character.

Fixes: eb61a4fb14d2 ("xen: fix header guard generation for asm-generic headers")
Reported-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
---
 xen/scripts/Makefile.asm-generic | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/scripts/Makefile.asm-generic b/xen/scripts/Makefile.asm-generic
index f6850758c54b..4e628e116adf 100644
--- a/xen/scripts/Makefile.asm-generic
+++ b/xen/scripts/Makefile.asm-generic
@@ -34,7 +34,7 @@ unwanted    := $(filter-out $(generic-y) $(generated-y),$(old-headers))
 quiet_cmd_wrap = WRAP    $@
       cmd_wrap = \
 	arch=$$(echo $@ | sed -n 's:.*arch/\([^/]*\)/.*:\1:p' | tr a-z A-Z); \
-	upper=$$(echo $*.h | tr a-z A-Z | tr '/.-' '__'); \
+	upper=$$(echo $*.h | tr a-z A-Z | tr '/.-' '___'); \
 	echo "\#ifndef $${arch}_GENERIC_$${upper}" > $@.new; \
 	echo "\#define $${arch}_GENERIC_$${upper}" >> $@.new; \
 	echo "\#include <asm-generic/$*.h>" >> $@.new; \
-- 
2.43.0

Re: [XEN PATCH] xen: fix unspecified behavior in tr invocation

Posted by Jan Beulich 4 months ago

On 26.06.2025 16:59, Nicola Vetrini wrote:
> The result of the command is undefined according to the specification if
> the "string2" argument in tr is shorter than "string1". GNU tr behaves
> correctly by extending "string2" to repeat the last character.
> 
> Fixes: eb61a4fb14d2 ("xen: fix header guard generation for asm-generic headers")
> Reported-by: Jan Beulich <jbeulich@suse.com>
> Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>

Reviewed-by: Jan Beulich <jbeulich@suse.com>