lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Wed, 1 Nov 2017 09:55:06 +0000 From: Suzuki K Poulose <Suzuki.Poulose@....com> To: Julien Thierry <julien.thierry@....com>, linux-arm-kernel@...ts.infradead.org Cc: mathieu.poirier@...aro.org, coresight@...ts.linaro.org, linux-kernel@...r.kernel.org, rob.walker@....com, mike.leach@...aro.org Subject: Re: [PATCH 02/17] coresight tmc: Hide trace buffer handling for file read On 20/10/17 13:34, Julien Thierry wrote: > Hi Suzuki, > > On 19/10/17 18:15, Suzuki K Poulose wrote: >> At the moment we adjust the buffer pointers for reading the trace >> data via misc device in the common code for ETF/ETB and ETR. Since >> we are going to change how we manage the buffer for ETR, let us >> move the buffer manipulation to the respective driver files, hiding >> it from the common code. We do so by adding type specific helpers >> for finding the length of data and the pointer to the buffer, >> for a given length at a file position. >> >> Cc: Mathieu Poirier <mathieu.poirier@...aro.org> >> Signed-off-by: Suzuki K Poulose <suzuki.poulose@....com> >> --- >> drivers/hwtracing/coresight/coresight-tmc-etf.c | 16 ++++++++++++ >> drivers/hwtracing/coresight/coresight-tmc-etr.c | 33 ++++++++++++++++++++++++ >> drivers/hwtracing/coresight/coresight-tmc.c | 34 ++++++++++++++----------- >> drivers/hwtracing/coresight/coresight-tmc.h | 4 +++ >> 4 files changed, 72 insertions(+), 15 deletions(-) >> >> diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c >> index e2513b786242..0b6f1eb746de 100644 >> --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c >> +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c >> @@ -120,6 +120,22 @@ static void tmc_etf_disable_hw(struct tmc_drvdata *drvdata) >> CS_LOCK(drvdata->base); >> } >> +/* >> + * Return the available trace data in the buffer from @pos, with >> + * a maximum limit of @len, updating the @bufpp on where to >> + * find it. >> + */ >> +ssize_t tmc_etb_get_sysfs_trace(struct tmc_drvdata *drvdata, >> + loff_t pos, size_t len, char **bufpp) >> +{ >> + /* Adjust the len to available size @pos */ >> + if (pos + len > drvdata->len) >> + len = drvdata->len - pos; >> + if (len > 0) > > Do we have some guarantee that "pos <= drvdata->len"? because since len is unsigned this check only covers the case were len is 0. > > Maybe it would be better to use a signed variable to store the result of the difference. > >> + *bufpp = drvdata->buf + pos; >> + * Return the available trace data in the buffer @pos, with a maximum >> + * limit of @len, also updating the @bufpp on where to find it. >> + */ >> +ssize_t tmc_etr_get_sysfs_trace(struct tmc_drvdata *drvdata, >> + loff_t pos, size_t len, char **bufpp) >> +{ >> + char *bufp = drvdata->buf + pos; >> + char *bufend = (char *)(drvdata->vaddr + drvdata->size); >> + >> + /* Adjust the len to available size @pos */ >> + if (pos + len > drvdata->len) >> + len = drvdata->len - pos; >> + >> + if (len <= 0) >> + return len; > > Similar issue here. Thanks for spotting. I will fix it. Cheers
Powered by blists - more mailing lists