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| author | Chris Down <chris@chrisdown.name> | 2021-06-15 17:52:45 +0100 |
|---|---|---|
| committer | Petr Mladek <pmladek@suse.com> | 2021-07-19 11:39:28 +0200 |
| commit | 91027d0a7a0e309b94674923dc1b245b709b5c1e (patch) | |
| tree | 237323e76bbba832797eb067315c7b9e1d232c0c /lib/string_helpers.c | |
| parent | e73f0f0ee7541171d89f2e2491130c7771ba58d3 (diff) | |
string_helpers: Escape double quotes in escape_special
From an abstract point of view, escape_special's counterpart,
unescape_special, already handles the unescaping of blackslashed double
quote sequences.
As a more practical example, printk indexing is an example case where
this is already practically useful. Compare an example with
`ESCAPE_SPECIAL | ESCAPE_SPACE`, with quotes not escaped:
[root@ktst ~]# grep drivers/pci/pci-stub.c:69 /sys/kernel/debug/printk/index/vmlinux
<4> drivers/pci/pci-stub.c:69 pci_stub_init "pci-stub: invalid ID string "%s"\n"
...and the same after this patch:
[root@ktst ~]# grep drivers/pci/pci-stub.c:69 /sys/kernel/debug/printk/index/vmlinux
<4> drivers/pci/pci-stub.c:69 pci_stub_init "pci-stub: invalid ID string \"%s\"\n"
One can of course, alternatively, use ESCAPE_APPEND with a quote in
@only, but without this patch quotes are coerced into hex or octal which
can hurt readability quite significantly.
I've checked uses of ESCAPE_SPECIAL and %pE across the codebase, and I'm
pretty confident that this shouldn't affect any stable interfaces.
Signed-off-by: Chris Down <chris@chrisdown.name>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/af144c5b75e41ce417386253ba2694456bc04118.1623775748.git.chris@chrisdown.name
Diffstat (limited to 'lib/string_helpers.c')
| -rw-r--r-- | lib/string_helpers.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/lib/string_helpers.c b/lib/string_helpers.c index 5a35c7e16e96..3806a52ce697 100644 --- a/lib/string_helpers.c +++ b/lib/string_helpers.c @@ -361,6 +361,9 @@ static bool escape_special(unsigned char c, char **dst, char *end) case '\e': to = 'e'; break; + case '"': + to = '"'; + break; default: return false; } @@ -474,6 +477,7 @@ static bool escape_hex(unsigned char c, char **dst, char *end) * '\t' - horizontal tab * '\v' - vertical tab * %ESCAPE_SPECIAL: + * '\"' - double quote * '\\' - backslash * '\a' - alert (BEL) * '\e' - escape |