| Message ID | 20180305090806.32211-1-cascardo@canonical.com |
|---|---|
| State | New |
| Headers | show |
| Series | [Artful,SRU] kdump: write correct address of mem_section into vmcoreinfo | expand |
On 03/05/18 10:08, Thadeu Lima de Souza Cascardo wrote: > From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> > > BugLink: http://bugs.launchpad.net/bugs/1750021 > > Depending on configuration mem_section can now be an array or a pointer > to an array allocated dynamically. In most cases, we can continue to > refer to it as 'mem_section' regardless of what it is. > > But there's one exception: '&mem_section' means "address of the array" > if mem_section is an array, but if mem_section is a pointer, it would > mean "address of the pointer". > > We've stepped onto this in kdump code. VMCOREINFO_SYMBOL(mem_section) > writes down address of pointer into vmcoreinfo, not array as we wanted. > > Let's introduce VMCOREINFO_SYMBOL_ARRAY() that would handle the > situation correctly for both cases. > > Link: http://lkml.kernel.org/r/20180112162532.35896-1-kirill.shutemov@linux.intel.com > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > Fixes: 83e3c48729d9 ("mm/sparsemem: Allocate mem_section at runtime for CONFIG_SPARSEMEM_EXTREME=y") > Acked-by: Baoquan He <bhe@redhat.com> > Acked-by: Dave Young <dyoung@redhat.com> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: "H. Peter Anvin" <hpa@zytor.com> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: Dave Young <dyoung@redhat.com> > Cc: Baoquan He <bhe@redhat.com> > Cc: Vivek Goyal <vgoyal@redhat.com> > Cc: <stable@vger.kernel.org> > Signed-off-by: Andrew Morton <akpm@linux-foundation.org> > Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> > (cherry picked from commit a0b1280368d1e91ab72f849ef095b4f07a39bbf1) > Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> > --- > include/linux/crash_core.h | 2 ++ > kernel/crash_core.c | 2 +- > 2 files changed, 3 insertions(+), 1 deletion(-) > > diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h > index 2df2118fbe13..b1c889225e9a 100644 > --- a/include/linux/crash_core.h > +++ b/include/linux/crash_core.h > @@ -41,6 +41,8 @@ phys_addr_t paddr_vmcoreinfo_note(void); > vmcoreinfo_append_str("PAGESIZE=%ld\n", value) > #define VMCOREINFO_SYMBOL(name) \ > vmcoreinfo_append_str("SYMBOL(%s)=%lx\n", #name, (unsigned long)&name) > +#define VMCOREINFO_SYMBOL_ARRAY(name) \ > + vmcoreinfo_append_str("SYMBOL(%s)=%lx\n", #name, (unsigned long)name) > #define VMCOREINFO_SIZE(name) \ > vmcoreinfo_append_str("SIZE(%s)=%lu\n", #name, \ > (unsigned long)sizeof(name)) > diff --git a/kernel/crash_core.c b/kernel/crash_core.c > index 6db80fc0810b..2d90996dbe77 100644 > --- a/kernel/crash_core.c > +++ b/kernel/crash_core.c > @@ -409,7 +409,7 @@ static int __init crash_save_vmcoreinfo_init(void) > VMCOREINFO_SYMBOL(contig_page_data); > #endif > #ifdef CONFIG_SPARSEMEM > - VMCOREINFO_SYMBOL(mem_section); > + VMCOREINFO_SYMBOL_ARRAY(mem_section); > VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS); > VMCOREINFO_STRUCT_SIZE(mem_section); > VMCOREINFO_OFFSET(mem_section, section_mem_map); > Clean cherry pick, tested to fix a regression. Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Acked-by: Marcelo Henrique Cerri <marcelo.cerri@canonical.com>
On 03/05/18 10:08, Thadeu Lima de Souza Cascardo wrote: > From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> > > BugLink: http://bugs.launchpad.net/bugs/1750021 > > Depending on configuration mem_section can now be an array or a pointer > to an array allocated dynamically. In most cases, we can continue to > refer to it as 'mem_section' regardless of what it is. > > But there's one exception: '&mem_section' means "address of the array" > if mem_section is an array, but if mem_section is a pointer, it would > mean "address of the pointer". > > We've stepped onto this in kdump code. VMCOREINFO_SYMBOL(mem_section) > writes down address of pointer into vmcoreinfo, not array as we wanted. > > Let's introduce VMCOREINFO_SYMBOL_ARRAY() that would handle the > situation correctly for both cases. > > Link: http://lkml.kernel.org/r/20180112162532.35896-1-kirill.shutemov@linux.intel.com > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > Fixes: 83e3c48729d9 ("mm/sparsemem: Allocate mem_section at runtime for CONFIG_SPARSEMEM_EXTREME=y") > Acked-by: Baoquan He <bhe@redhat.com> > Acked-by: Dave Young <dyoung@redhat.com> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: "H. Peter Anvin" <hpa@zytor.com> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: Dave Young <dyoung@redhat.com> > Cc: Baoquan He <bhe@redhat.com> > Cc: Vivek Goyal <vgoyal@redhat.com> > Cc: <stable@vger.kernel.org> > Signed-off-by: Andrew Morton <akpm@linux-foundation.org> > Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> > (cherry picked from commit a0b1280368d1e91ab72f849ef095b4f07a39bbf1) > Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> > --- > include/linux/crash_core.h | 2 ++ > kernel/crash_core.c | 2 +- > 2 files changed, 3 insertions(+), 1 deletion(-) > > diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h > index 2df2118fbe13..b1c889225e9a 100644 > --- a/include/linux/crash_core.h > +++ b/include/linux/crash_core.h > @@ -41,6 +41,8 @@ phys_addr_t paddr_vmcoreinfo_note(void); > vmcoreinfo_append_str("PAGESIZE=%ld\n", value) > #define VMCOREINFO_SYMBOL(name) \ > vmcoreinfo_append_str("SYMBOL(%s)=%lx\n", #name, (unsigned long)&name) > +#define VMCOREINFO_SYMBOL_ARRAY(name) \ > + vmcoreinfo_append_str("SYMBOL(%s)=%lx\n", #name, (unsigned long)name) > #define VMCOREINFO_SIZE(name) \ > vmcoreinfo_append_str("SIZE(%s)=%lu\n", #name, \ > (unsigned long)sizeof(name)) > diff --git a/kernel/crash_core.c b/kernel/crash_core.c > index 6db80fc0810b..2d90996dbe77 100644 > --- a/kernel/crash_core.c > +++ b/kernel/crash_core.c > @@ -409,7 +409,7 @@ static int __init crash_save_vmcoreinfo_init(void) > VMCOREINFO_SYMBOL(contig_page_data); > #endif > #ifdef CONFIG_SPARSEMEM > - VMCOREINFO_SYMBOL(mem_section); > + VMCOREINFO_SYMBOL_ARRAY(mem_section); > VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS); > VMCOREINFO_STRUCT_SIZE(mem_section); > VMCOREINFO_OFFSET(mem_section, section_mem_map); > Applied to artful/master-next-backlog branch. Thanks, Kleber
diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h index 2df2118fbe13..b1c889225e9a 100644 --- a/include/linux/crash_core.h +++ b/include/linux/crash_core.h @@ -41,6 +41,8 @@ phys_addr_t paddr_vmcoreinfo_note(void); vmcoreinfo_append_str("PAGESIZE=%ld\n", value) #define VMCOREINFO_SYMBOL(name) \ vmcoreinfo_append_str("SYMBOL(%s)=%lx\n", #name, (unsigned long)&name) +#define VMCOREINFO_SYMBOL_ARRAY(name) \ + vmcoreinfo_append_str("SYMBOL(%s)=%lx\n", #name, (unsigned long)name) #define VMCOREINFO_SIZE(name) \ vmcoreinfo_append_str("SIZE(%s)=%lu\n", #name, \ (unsigned long)sizeof(name)) diff --git a/kernel/crash_core.c b/kernel/crash_core.c index 6db80fc0810b..2d90996dbe77 100644 --- a/kernel/crash_core.c +++ b/kernel/crash_core.c @@ -409,7 +409,7 @@ static int __init crash_save_vmcoreinfo_init(void) VMCOREINFO_SYMBOL(contig_page_data); #endif #ifdef CONFIG_SPARSEMEM - VMCOREINFO_SYMBOL(mem_section); + VMCOREINFO_SYMBOL_ARRAY(mem_section); VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS); VMCOREINFO_STRUCT_SIZE(mem_section); VMCOREINFO_OFFSET(mem_section, section_mem_map);