| Message ID | 20230630145449.2312-2-frankja@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | s390x: Improve console handling | expand |
On Fri, 30 Jun 2023 14:54:47 +0000 Janosch Frank <frankja@linux.ibm.com> wrote: > Without the \r the output of the ASCII console takes a lot of > additional effort to read in comparison to the line mode console. > > Signed-off-by: Janosch Frank <frankja@linux.ibm.com> > --- > lib/s390x/sclp-console.c | 15 ++++++++++++++- > 1 file changed, 14 insertions(+), 1 deletion(-) > > diff --git a/lib/s390x/sclp-console.c b/lib/s390x/sclp-console.c > index 19c74e46..384080b0 100644 > --- a/lib/s390x/sclp-console.c > +++ b/lib/s390x/sclp-console.c > @@ -97,14 +97,27 @@ static void sclp_print_ascii(const char *str) > { > int len = strlen(str); > WriteEventData *sccb = (void *)_sccb; > + char *str_dest = (char *)&sccb->msg; > + int i = 0; > > sclp_mark_busy(); > memset(sccb, 0, sizeof(*sccb)); > + > + for (; i < len; i++) { > + *str_dest = str[i]; > + str_dest++; > + /* Add a \r to the \n */ > + if (str[i] == '\n') { > + *str_dest = '\r'; > + str_dest++; > + } > + } > + > + len = (uintptr_t)str_dest - (uintptr_t)&sccb->msg; some strings will therefore potentially overflow the SCCB sclp_print() refuses to print more than 2kB, with this patch that limit could potentially be crossed can you please briefly explain in a comment why that is ok? (or maybe that is not ok? then fix it somehow :) ) > sccb->h.length = offsetof(WriteEventData, msg) + len; > sccb->h.function_code = SCLP_FC_NORMAL_WRITE; > sccb->ebh.length = sizeof(EventBufferHeader) + len; > sccb->ebh.type = SCLP_EVENT_ASCII_CONSOLE_DATA; > - memcpy(&sccb->msg, str, len); > > sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb); > }
On 6/30/23 17:12, Claudio Imbrenda wrote: > On Fri, 30 Jun 2023 14:54:47 +0000 > Janosch Frank <frankja@linux.ibm.com> wrote: > >> Without the \r the output of the ASCII console takes a lot of >> additional effort to read in comparison to the line mode console. >> >> Signed-off-by: Janosch Frank <frankja@linux.ibm.com> >> --- >> lib/s390x/sclp-console.c | 15 ++++++++++++++- >> 1 file changed, 14 insertions(+), 1 deletion(-) >> >> diff --git a/lib/s390x/sclp-console.c b/lib/s390x/sclp-console.c >> index 19c74e46..384080b0 100644 >> --- a/lib/s390x/sclp-console.c >> +++ b/lib/s390x/sclp-console.c >> @@ -97,14 +97,27 @@ static void sclp_print_ascii(const char *str) >> { >> int len = strlen(str); >> WriteEventData *sccb = (void *)_sccb; >> + char *str_dest = (char *)&sccb->msg; >> + int i = 0; >> >> sclp_mark_busy(); >> memset(sccb, 0, sizeof(*sccb)); >> + >> + for (; i < len; i++) { >> + *str_dest = str[i]; >> + str_dest++; >> + /* Add a \r to the \n */ >> + if (str[i] == '\n') { >> + *str_dest = '\r'; >> + str_dest++; >> + } >> + } >> + >> + len = (uintptr_t)str_dest - (uintptr_t)&sccb->msg; > > some strings will therefore potentially overflow the SCCB > > sclp_print() refuses to print more than 2kB, with this patch that limit > could potentially be crossed > > can you please briefly explain in a comment why that is ok? (or maybe > that is not ok? then fix it somehow :) ) I'd like to see someone find a useful application for printing 2kb in a single printf() call. Anyway, I could truncate the ASCII after the 2KB limit when adding the \r. I'm wondering how the line-mode console interprets the \r. If it ignores it, then we could also convert to \n\r for both consoles and check for 2kb when converting.
On Mon, 3 Jul 2023 13:46:29 +0200 Janosch Frank <frankja@linux.ibm.com> wrote: > On 6/30/23 17:12, Claudio Imbrenda wrote: > > On Fri, 30 Jun 2023 14:54:47 +0000 > > Janosch Frank <frankja@linux.ibm.com> wrote: > > > >> Without the \r the output of the ASCII console takes a lot of > >> additional effort to read in comparison to the line mode console. > >> > >> Signed-off-by: Janosch Frank <frankja@linux.ibm.com> > >> --- > >> lib/s390x/sclp-console.c | 15 ++++++++++++++- > >> 1 file changed, 14 insertions(+), 1 deletion(-) > >> > >> diff --git a/lib/s390x/sclp-console.c b/lib/s390x/sclp-console.c > >> index 19c74e46..384080b0 100644 > >> --- a/lib/s390x/sclp-console.c > >> +++ b/lib/s390x/sclp-console.c > >> @@ -97,14 +97,27 @@ static void sclp_print_ascii(const char *str) > >> { > >> int len = strlen(str); > >> WriteEventData *sccb = (void *)_sccb; > >> + char *str_dest = (char *)&sccb->msg; > >> + int i = 0; > >> > >> sclp_mark_busy(); > >> memset(sccb, 0, sizeof(*sccb)); > >> + > >> + for (; i < len; i++) { > >> + *str_dest = str[i]; > >> + str_dest++; > >> + /* Add a \r to the \n */ > >> + if (str[i] == '\n') { > >> + *str_dest = '\r'; > >> + str_dest++; > >> + } > >> + } > >> + > >> + len = (uintptr_t)str_dest - (uintptr_t)&sccb->msg; > > > > some strings will therefore potentially overflow the SCCB > > > > sclp_print() refuses to print more than 2kB, with this patch that limit > > could potentially be crossed > > > > can you please briefly explain in a comment why that is ok? (or maybe > > that is not ok? then fix it somehow :) ) > > I'd like to see someone find a useful application for printing 2kb in a > single printf() call. I'm with you there > > Anyway, I could truncate the ASCII after the 2KB limit when adding the \r. sounds like a plan > > I'm wondering how the line-mode console interprets the \r. If it ignores > it, then we could also convert to \n\r for both consoles and check for > 2kb when converting. is \n\r the right order? what about \r\n ?
diff --git a/lib/s390x/sclp-console.c b/lib/s390x/sclp-console.c index 19c74e46..384080b0 100644 --- a/lib/s390x/sclp-console.c +++ b/lib/s390x/sclp-console.c @@ -97,14 +97,27 @@ static void sclp_print_ascii(const char *str) { int len = strlen(str); WriteEventData *sccb = (void *)_sccb; + char *str_dest = (char *)&sccb->msg; + int i = 0; sclp_mark_busy(); memset(sccb, 0, sizeof(*sccb)); + + for (; i < len; i++) { + *str_dest = str[i]; + str_dest++; + /* Add a \r to the \n */ + if (str[i] == '\n') { + *str_dest = '\r'; + str_dest++; + } + } + + len = (uintptr_t)str_dest - (uintptr_t)&sccb->msg; sccb->h.length = offsetof(WriteEventData, msg) + len; sccb->h.function_code = SCLP_FC_NORMAL_WRITE; sccb->ebh.length = sizeof(EventBufferHeader) + len; sccb->ebh.type = SCLP_EVENT_ASCII_CONSOLE_DATA; - memcpy(&sccb->msg, str, len); sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb); }
Without the \r the output of the ASCII console takes a lot of additional effort to read in comparison to the line mode console. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> --- lib/s390x/sclp-console.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-)