| Message ID | 20230912082950.856977-1-hbathini@linux.ibm.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 86328b338c3996b814417dd68e3f899a1a649059 |
| Headers | show |
| Series | [v3,1/2] vmcore: remove dependency with is_kdump_kernel() for exporting vmcore | expand |
On 09/12/23 at 01:59pm, Hari Bathini wrote: > Currently, is_kdump_kernel() returns true when elfcorehdr_addr is set. > While elfcorehdr_addr is set for kexec based kernel dump mechanism, > alternate dump capturing methods like fadump [1] also set it to export > the vmcore. Since, is_kdump_kernel() is used to restrict resources in > crash dump capture kernel and such restrictions may not be desirable > for fadump, allow is_kdump_kernel() to be defined differently for such > scenarios. With this, is_kdump_kernel() could be false while vmcore is > usable. So, remove unnecessary dependency with is_kdump_kernel(), for > exporting vmcore. > > [1] https://docs.kernel.org/powerpc/firmware-assisted-dump.html > > Suggested-by: Michael Ellerman <mpe@ellerman.id.au> > Signed-off-by: Hari Bathini <hbathini@linux.ibm.com> > --- > > Changes in v3: > * Decoupled is_vmcore_usable() & vmcore_unusable() from is_kdump_kernel() > as suggested here: > https://lore.kernel.org/linuxppc-dev/ZP7si3UMVpPfYV+w@MiWiFi-R3L-srv/T/#m13ae5a7e4ba6f4d8397f0f66581832292eee3a85 > > > include/linux/crash_dump.h | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) LGTM, Acked-by: Baoquan He <bhe@redhat.com> > > diff --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h > index 0f3a656293b0..acc55626afdc 100644 > --- a/include/linux/crash_dump.h > +++ b/include/linux/crash_dump.h > @@ -50,6 +50,7 @@ void vmcore_cleanup(void); > #define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x)) > #endif > > +#ifndef is_kdump_kernel > /* > * is_kdump_kernel() checks whether this kernel is booting after a panic of > * previous kernel or not. This is determined by checking if previous kernel > @@ -64,6 +65,7 @@ static inline bool is_kdump_kernel(void) > { > return elfcorehdr_addr != ELFCORE_ADDR_MAX; > } > +#endif > > /* is_vmcore_usable() checks if the kernel is booting after a panic and > * the vmcore region is usable. > @@ -75,7 +77,8 @@ static inline bool is_kdump_kernel(void) > > static inline int is_vmcore_usable(void) > { > - return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0; > + return elfcorehdr_addr != ELFCORE_ADDR_ERR && > + elfcorehdr_addr != ELFCORE_ADDR_MAX ? 1 : 0; > } > > /* vmcore_unusable() marks the vmcore as unusable, > @@ -84,8 +87,7 @@ static inline int is_vmcore_usable(void) > > static inline void vmcore_unusable(void) > { > - if (is_kdump_kernel()) > - elfcorehdr_addr = ELFCORE_ADDR_ERR; > + elfcorehdr_addr = ELFCORE_ADDR_ERR; > } > > /** > -- > 2.41.0 >
On Tue, 12 Sep 2023 13:59:49 +0530, Hari Bathini wrote: > Currently, is_kdump_kernel() returns true when elfcorehdr_addr is set. > While elfcorehdr_addr is set for kexec based kernel dump mechanism, > alternate dump capturing methods like fadump [1] also set it to export > the vmcore. Since, is_kdump_kernel() is used to restrict resources in > crash dump capture kernel and such restrictions may not be desirable > for fadump, allow is_kdump_kernel() to be defined differently for such > scenarios. With this, is_kdump_kernel() could be false while vmcore is > usable. So, remove unnecessary dependency with is_kdump_kernel(), for > exporting vmcore. > > [...] Applied to powerpc/next. [1/2] vmcore: remove dependency with is_kdump_kernel() for exporting vmcore https://git.kernel.org/powerpc/c/86328b338c3996b814417dd68e3f899a1a649059 [2/2] powerpc/fadump: make is_kdump_kernel() return false when fadump is active https://git.kernel.org/powerpc/c/b098f1c32365304633077d73e4ae21c72d4241b3 cheers
diff --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h index 0f3a656293b0..acc55626afdc 100644 --- a/include/linux/crash_dump.h +++ b/include/linux/crash_dump.h @@ -50,6 +50,7 @@ void vmcore_cleanup(void); #define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x)) #endif +#ifndef is_kdump_kernel /* * is_kdump_kernel() checks whether this kernel is booting after a panic of * previous kernel or not. This is determined by checking if previous kernel @@ -64,6 +65,7 @@ static inline bool is_kdump_kernel(void) { return elfcorehdr_addr != ELFCORE_ADDR_MAX; } +#endif /* is_vmcore_usable() checks if the kernel is booting after a panic and * the vmcore region is usable. @@ -75,7 +77,8 @@ static inline bool is_kdump_kernel(void) static inline int is_vmcore_usable(void) { - return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0; + return elfcorehdr_addr != ELFCORE_ADDR_ERR && + elfcorehdr_addr != ELFCORE_ADDR_MAX ? 1 : 0; } /* vmcore_unusable() marks the vmcore as unusable, @@ -84,8 +87,7 @@ static inline int is_vmcore_usable(void) static inline void vmcore_unusable(void) { - if (is_kdump_kernel()) - elfcorehdr_addr = ELFCORE_ADDR_ERR; + elfcorehdr_addr = ELFCORE_ADDR_ERR; } /**
Currently, is_kdump_kernel() returns true when elfcorehdr_addr is set. While elfcorehdr_addr is set for kexec based kernel dump mechanism, alternate dump capturing methods like fadump [1] also set it to export the vmcore. Since, is_kdump_kernel() is used to restrict resources in crash dump capture kernel and such restrictions may not be desirable for fadump, allow is_kdump_kernel() to be defined differently for such scenarios. With this, is_kdump_kernel() could be false while vmcore is usable. So, remove unnecessary dependency with is_kdump_kernel(), for exporting vmcore. [1] https://docs.kernel.org/powerpc/firmware-assisted-dump.html Suggested-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Hari Bathini <hbathini@linux.ibm.com> --- Changes in v3: * Decoupled is_vmcore_usable() & vmcore_unusable() from is_kdump_kernel() as suggested here: https://lore.kernel.org/linuxppc-dev/ZP7si3UMVpPfYV+w@MiWiFi-R3L-srv/T/#m13ae5a7e4ba6f4d8397f0f66581832292eee3a85 include/linux/crash_dump.h | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)