* [PATCH] mm: do not export ioremap_page_range symbol for external module @ 2017-01-22 12:58 ` zhongjiang 0 siblings, 0 replies; 10+ messages in thread From: zhongjiang @ 2017-01-22 12:58 UTC (permalink / raw) To: akpm, minchan, mhocko; +Cc: linux-mm, linux-kernel From: zhong jiang <zhongjiang@huawei.com> Recently, I find the ioremap_page_range had been abusing. The improper address mapping is a issue. it will result in the crash. so, remove the symbol. It can be replaced by the ioremap_cache or others symbol. Signed-off-by: zhong jiang <zhongjiang@huawei.com> --- lib/ioremap.c | 1 - 1 file changed, 1 deletion(-) diff --git a/lib/ioremap.c b/lib/ioremap.c index 86c8911..a3e14ce 100644 --- a/lib/ioremap.c +++ b/lib/ioremap.c @@ -144,4 +144,3 @@ int ioremap_page_range(unsigned long addr, return err; } -EXPORT_SYMBOL_GPL(ioremap_page_range); -- 1.8.3.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH] mm: do not export ioremap_page_range symbol for external module @ 2017-01-22 12:58 ` zhongjiang 0 siblings, 0 replies; 10+ messages in thread From: zhongjiang @ 2017-01-22 12:58 UTC (permalink / raw) To: akpm, minchan, mhocko; +Cc: linux-mm, linux-kernel From: zhong jiang <zhongjiang@huawei.com> Recently, I find the ioremap_page_range had been abusing. The improper address mapping is a issue. it will result in the crash. so, remove the symbol. It can be replaced by the ioremap_cache or others symbol. Signed-off-by: zhong jiang <zhongjiang@huawei.com> --- lib/ioremap.c | 1 - 1 file changed, 1 deletion(-) diff --git a/lib/ioremap.c b/lib/ioremap.c index 86c8911..a3e14ce 100644 --- a/lib/ioremap.c +++ b/lib/ioremap.c @@ -144,4 +144,3 @@ int ioremap_page_range(unsigned long addr, return err; } -EXPORT_SYMBOL_GPL(ioremap_page_range); -- 1.8.3.1 ^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH] mm: do not export ioremap_page_range symbol for external module 2017-01-22 12:58 ` zhongjiang @ 2017-01-22 22:25 ` John Hubbard -1 siblings, 0 replies; 10+ messages in thread From: John Hubbard @ 2017-01-22 22:25 UTC (permalink / raw) To: zhongjiang, akpm, minchan, mhocko; +Cc: linux-mm, linux-kernel On 01/22/2017 04:58 AM, zhongjiang wrote: > From: zhong jiang <zhongjiang@huawei.com> > > Recently, I find the ioremap_page_range had been abusing. The improper > address mapping is a issue. it will result in the crash. so, remove > the symbol. It can be replaced by the ioremap_cache or others symbol. Hi Zhong, After thinking about this for a bit, and looking through our own (out-of-tree) kernel modules, I think you have a good point. I just can't see any reason for a driver to call ioremap_page_range directly. So the code change looks good to me. For the commit description, here is a proposed re-wording, optional, that perhaps may be a little clearer. See if you like it? ------- Recently, I've found cases in which ioremap_page_range was used incorrectly, in external modules, leading to crashes. This can be partly attributed to the fact that ioremap_page_range is lower-level, with fewer protections, as compared to the other functions that an external module would typically call. Those include: ioremap_cache ioremap_nocache ioremap_prot ioremap_uc ioremap_wc ioremap_wt ...each of which wraps __ioremap_caller, which in turn provides a safer way to achieve the mapping. Therefore, stop EXPORT-ing ioremap_page_range. ------- I may get some heat for this if another out-of-tree driver needs that symbol, but if no one else pops up and shrieks, you can add: Reviewed-by: John Hubbard <jhubbard@nvidia.com> thanks, john h > > Signed-off-by: zhong jiang <zhongjiang@huawei.com> > --- > lib/ioremap.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/lib/ioremap.c b/lib/ioremap.c > index 86c8911..a3e14ce 100644 > --- a/lib/ioremap.c > +++ b/lib/ioremap.c > @@ -144,4 +144,3 @@ int ioremap_page_range(unsigned long addr, > > return err; > } > -EXPORT_SYMBOL_GPL(ioremap_page_range); > -- > 1.8.3.1 > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] mm: do not export ioremap_page_range symbol for external module @ 2017-01-22 22:25 ` John Hubbard 0 siblings, 0 replies; 10+ messages in thread From: John Hubbard @ 2017-01-22 22:25 UTC (permalink / raw) To: zhongjiang, akpm, minchan, mhocko; +Cc: linux-mm, linux-kernel On 01/22/2017 04:58 AM, zhongjiang wrote: > From: zhong jiang <zhongjiang@huawei.com> > > Recently, I find the ioremap_page_range had been abusing. The improper > address mapping is a issue. it will result in the crash. so, remove > the symbol. It can be replaced by the ioremap_cache or others symbol. Hi Zhong, After thinking about this for a bit, and looking through our own (out-of-tree) kernel modules, I think you have a good point. I just can't see any reason for a driver to call ioremap_page_range directly. So the code change looks good to me. For the commit description, here is a proposed re-wording, optional, that perhaps may be a little clearer. See if you like it? ------- Recently, I've found cases in which ioremap_page_range was used incorrectly, in external modules, leading to crashes. This can be partly attributed to the fact that ioremap_page_range is lower-level, with fewer protections, as compared to the other functions that an external module would typically call. Those include: ioremap_cache ioremap_nocache ioremap_prot ioremap_uc ioremap_wc ioremap_wt ...each of which wraps __ioremap_caller, which in turn provides a safer way to achieve the mapping. Therefore, stop EXPORT-ing ioremap_page_range. ------- I may get some heat for this if another out-of-tree driver needs that symbol, but if no one else pops up and shrieks, you can add: Reviewed-by: John Hubbard <jhubbard@nvidia.com> thanks, john h > > Signed-off-by: zhong jiang <zhongjiang@huawei.com> > --- > lib/ioremap.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/lib/ioremap.c b/lib/ioremap.c > index 86c8911..a3e14ce 100644 > --- a/lib/ioremap.c > +++ b/lib/ioremap.c > @@ -144,4 +144,3 @@ int ioremap_page_range(unsigned long addr, > > return err; > } > -EXPORT_SYMBOL_GPL(ioremap_page_range); > -- > 1.8.3.1 > ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] mm: do not export ioremap_page_range symbol for external module 2017-01-22 12:58 ` zhongjiang @ 2017-01-23 1:14 ` zhong jiang -1 siblings, 0 replies; 10+ messages in thread From: zhong jiang @ 2017-01-23 1:14 UTC (permalink / raw) To: akpm, minchan, mhocko; +Cc: linux-mm, linux-kernel On 2017/1/22 20:58, zhongjiang wrote: > From: zhong jiang <zhongjiang@huawei.com> > > Recently, I find the ioremap_page_range had been abusing. The improper > address mapping is a issue. it will result in the crash. so, remove > the symbol. It can be replaced by the ioremap_cache or others symbol. > > Signed-off-by: zhong jiang <zhongjiang@huawei.com> > --- > lib/ioremap.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/lib/ioremap.c b/lib/ioremap.c > index 86c8911..a3e14ce 100644 > --- a/lib/ioremap.c > +++ b/lib/ioremap.c > @@ -144,4 +144,3 @@ int ioremap_page_range(unsigned long addr, > > return err; > } > -EXPORT_SYMBOL_GPL(ioremap_page_range); self nack -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] mm: do not export ioremap_page_range symbol for external module @ 2017-01-23 1:14 ` zhong jiang 0 siblings, 0 replies; 10+ messages in thread From: zhong jiang @ 2017-01-23 1:14 UTC (permalink / raw) To: akpm, minchan, mhocko; +Cc: linux-mm, linux-kernel On 2017/1/22 20:58, zhongjiang wrote: > From: zhong jiang <zhongjiang@huawei.com> > > Recently, I find the ioremap_page_range had been abusing. The improper > address mapping is a issue. it will result in the crash. so, remove > the symbol. It can be replaced by the ioremap_cache or others symbol. > > Signed-off-by: zhong jiang <zhongjiang@huawei.com> > --- > lib/ioremap.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/lib/ioremap.c b/lib/ioremap.c > index 86c8911..a3e14ce 100644 > --- a/lib/ioremap.c > +++ b/lib/ioremap.c > @@ -144,4 +144,3 @@ int ioremap_page_range(unsigned long addr, > > return err; > } > -EXPORT_SYMBOL_GPL(ioremap_page_range); self nack ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] mm: do not export ioremap_page_range symbol for external module 2017-01-23 1:14 ` zhong jiang @ 2017-01-23 1:30 ` John Hubbard -1 siblings, 0 replies; 10+ messages in thread From: John Hubbard @ 2017-01-23 1:30 UTC (permalink / raw) To: zhong jiang, akpm, minchan, mhocko; +Cc: linux-mm, linux-kernel On 01/22/2017 05:14 PM, zhong jiang wrote: > On 2017/1/22 20:58, zhongjiang wrote: >> From: zhong jiang <zhongjiang@huawei.com> >> >> Recently, I find the ioremap_page_range had been abusing. The improper >> address mapping is a issue. it will result in the crash. so, remove >> the symbol. It can be replaced by the ioremap_cache or others symbol. >> >> Signed-off-by: zhong jiang <zhongjiang@huawei.com> >> --- >> lib/ioremap.c | 1 - >> 1 file changed, 1 deletion(-) >> >> diff --git a/lib/ioremap.c b/lib/ioremap.c >> index 86c8911..a3e14ce 100644 >> --- a/lib/ioremap.c >> +++ b/lib/ioremap.c >> @@ -144,4 +144,3 @@ int ioremap_page_range(unsigned long addr, >> >> return err; >> } >> -EXPORT_SYMBOL_GPL(ioremap_page_range); > self nack > heh. What changed your mind? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] mm: do not export ioremap_page_range symbol for external module @ 2017-01-23 1:30 ` John Hubbard 0 siblings, 0 replies; 10+ messages in thread From: John Hubbard @ 2017-01-23 1:30 UTC (permalink / raw) To: zhong jiang, akpm, minchan, mhocko; +Cc: linux-mm, linux-kernel On 01/22/2017 05:14 PM, zhong jiang wrote: > On 2017/1/22 20:58, zhongjiang wrote: >> From: zhong jiang <zhongjiang@huawei.com> >> >> Recently, I find the ioremap_page_range had been abusing. The improper >> address mapping is a issue. it will result in the crash. so, remove >> the symbol. It can be replaced by the ioremap_cache or others symbol. >> >> Signed-off-by: zhong jiang <zhongjiang@huawei.com> >> --- >> lib/ioremap.c | 1 - >> 1 file changed, 1 deletion(-) >> >> diff --git a/lib/ioremap.c b/lib/ioremap.c >> index 86c8911..a3e14ce 100644 >> --- a/lib/ioremap.c >> +++ b/lib/ioremap.c >> @@ -144,4 +144,3 @@ int ioremap_page_range(unsigned long addr, >> >> return err; >> } >> -EXPORT_SYMBOL_GPL(ioremap_page_range); > self nack > heh. What changed your mind? ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] mm: do not export ioremap_page_range symbol for external module 2017-01-23 1:30 ` John Hubbard @ 2017-01-23 11:52 ` zhong jiang -1 siblings, 0 replies; 10+ messages in thread From: zhong jiang @ 2017-01-23 11:52 UTC (permalink / raw) To: John Hubbard; +Cc: akpm, minchan, mhocko, linux-mm, linux-kernel On 2017/1/23 9:30, John Hubbard wrote: > > > On 01/22/2017 05:14 PM, zhong jiang wrote: >> On 2017/1/22 20:58, zhongjiang wrote: >>> From: zhong jiang <zhongjiang@huawei.com> >>> >>> Recently, I find the ioremap_page_range had been abusing. The improper >>> address mapping is a issue. it will result in the crash. so, remove >>> the symbol. It can be replaced by the ioremap_cache or others symbol. >>> >>> Signed-off-by: zhong jiang <zhongjiang@huawei.com> >>> --- >>> lib/ioremap.c | 1 - >>> 1 file changed, 1 deletion(-) >>> >>> diff --git a/lib/ioremap.c b/lib/ioremap.c >>> index 86c8911..a3e14ce 100644 >>> --- a/lib/ioremap.c >>> +++ b/lib/ioremap.c >>> @@ -144,4 +144,3 @@ int ioremap_page_range(unsigned long addr, >>> >>> return err; >>> } >>> -EXPORT_SYMBOL_GPL(ioremap_page_range); >> self nack >> > > heh. What changed your mind? > Very sorry, I mistake own kernel modules call it directly. Thank you review the patch . I will take your changelog and send it in v2. Thanks zhongjiang > . > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] mm: do not export ioremap_page_range symbol for external module @ 2017-01-23 11:52 ` zhong jiang 0 siblings, 0 replies; 10+ messages in thread From: zhong jiang @ 2017-01-23 11:52 UTC (permalink / raw) To: John Hubbard; +Cc: akpm, minchan, mhocko, linux-mm, linux-kernel On 2017/1/23 9:30, John Hubbard wrote: > > > On 01/22/2017 05:14 PM, zhong jiang wrote: >> On 2017/1/22 20:58, zhongjiang wrote: >>> From: zhong jiang <zhongjiang@huawei.com> >>> >>> Recently, I find the ioremap_page_range had been abusing. The improper >>> address mapping is a issue. it will result in the crash. so, remove >>> the symbol. It can be replaced by the ioremap_cache or others symbol. >>> >>> Signed-off-by: zhong jiang <zhongjiang@huawei.com> >>> --- >>> lib/ioremap.c | 1 - >>> 1 file changed, 1 deletion(-) >>> >>> diff --git a/lib/ioremap.c b/lib/ioremap.c >>> index 86c8911..a3e14ce 100644 >>> --- a/lib/ioremap.c >>> +++ b/lib/ioremap.c >>> @@ -144,4 +144,3 @@ int ioremap_page_range(unsigned long addr, >>> >>> return err; >>> } >>> -EXPORT_SYMBOL_GPL(ioremap_page_range); >> self nack >> > > heh. What changed your mind? > Very sorry, I mistake own kernel modules call it directly. Thank you review the patch . I will take your changelog and send it in v2. Thanks zhongjiang > . > ^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2017-01-23 11:57 UTC | newest] Thread overview: 10+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2017-01-22 12:58 [PATCH] mm: do not export ioremap_page_range symbol for external module zhongjiang 2017-01-22 12:58 ` zhongjiang 2017-01-22 22:25 ` John Hubbard 2017-01-22 22:25 ` John Hubbard 2017-01-23 1:14 ` zhong jiang 2017-01-23 1:14 ` zhong jiang 2017-01-23 1:30 ` John Hubbard 2017-01-23 1:30 ` John Hubbard 2017-01-23 11:52 ` zhong jiang 2017-01-23 11:52 ` zhong jiang
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