Messages in this thread | | | Subject | Re: [PATCH v2] kdb: Use strscpy with destination buffer size | From | Daniel Thompson <> | Date | Tue, 2 Oct 2018 16:53:16 +0100 |
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On 20/09/2018 13:59, Prarit Bhargava wrote: > gcc 8.1.0 warns with: > > kernel/debug/kdb/kdb_support.c: In function ‘kallsyms_symbol_next’: > kernel/debug/kdb/kdb_support.c:239:4: warning: ‘strncpy’ specified bound depends on the length of the source argument [-Wstringop-overflow=] > strncpy(prefix_name, name, strlen(name)+1); > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > kernel/debug/kdb/kdb_support.c:239:31: note: length computed here > > Use strscpy() with the destination buffer size, and use ellipses when > displaying truncated symbols. > > v2: Use strscpy() > > Signed-off-by: Prarit Bhargava <prarit@redhat.com> > Cc: Jonathan Toppins <jtoppins@redhat.com> > Cc: Jason Wessel <jason.wessel@windriver.com> > Cc: Daniel Thompson <daniel.thompson@linaro.org> > Cc: kgdb-bugreport@lists.sourceforge.net > --- > kernel/debug/kdb/kdb_io.c | 15 +++++++++------ > kernel/debug/kdb/kdb_private.h | 2 +- > kernel/debug/kdb/kdb_support.c | 10 +++++----- > 3 files changed, 15 insertions(+), 12 deletions(-) > > diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c > index ed5d34925ad0..6a4b41484afe 100644 > --- a/kernel/debug/kdb/kdb_io.c > +++ b/kernel/debug/kdb/kdb_io.c > @@ -216,7 +216,7 @@ static char *kdb_read(char *buffer, size_t bufsize) > int count; > int i; > int diag, dtab_count; > - int key; > + int key, buf_size, ret; > > > diag = kdbgetintenv("DTABCOUNT", &dtab_count); > @@ -336,9 +336,8 @@ static char *kdb_read(char *buffer, size_t bufsize) > else > p_tmp = tmpbuffer; > len = strlen(p_tmp); > - count = kallsyms_symbol_complete(p_tmp, > - sizeof(tmpbuffer) - > - (p_tmp - tmpbuffer)); > + buf_size = sizeof(tmpbuffer) - (p_tmp - tmpbuffer); > + count = kallsyms_symbol_complete(p_tmp, buf_size); > if (tab == 2 && count > 0) { > kdb_printf("\n%d symbols are found.", count); > if (count > dtab_count) { > @@ -350,9 +349,13 @@ static char *kdb_read(char *buffer, size_t bufsize) > } > kdb_printf("\n"); > for (i = 0; i < count; i++) { > - if (WARN_ON(!kallsyms_symbol_next(p_tmp, i))) > + ret = kallsyms_symbol_next(p_tmp, i, buf_size); > + if (WARN_ON(!ret)) > break; I'm getting confused by having two different branches on ret.
Don't get a WARN_ON() when ret == -E2BIG?
Daniel.
> - kdb_printf("%s ", p_tmp); > + if (ret != -E2BIG) > + kdb_printf("%s ", p_tmp); > + else > + kdb_printf("%s... ", p_tmp); > *(p_tmp + len) = '\0'; > } > if (i >= dtab_count)
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